Designing Buildings - User contributions [en]

National Graphene Institute

2015-11-05T11:00:09Z

CIBSE:

Article from the November 2015 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Ian MacAskill. 

The first big breakthrough in graphene took place in Manchester, and now the city has a £61m facility aimed at developing the material for everyday use. CH2M Hill’s Ian MacAskill describes the challenge of designing services for the extraordinarily complex National Graphene Institute. In 2004, two professors at the University of Manchester Andre Geim and Kostya Novoselov isolated graphene, and such is the fascination with the possibilities and properties of graphene, they wereawarded the Nobel Prize for Physics in 2010. Graphene is the world’s thinnest material and even though it’s only one-atom thick, it is 200 times stronger than steel and its superior strength, conductivity, stiffness and transparency mean its revolutionary properties have applications in electronics, energy and medicine. To capitalise on the work done by Geim and Novoselov, the University of Mancheseter has built a £61m state-of-the-art laboratory dedicated to the research and commercial development of graphene. The National Graphene Institute (NGI), designed by Jestico + Whiles is a five-storey glazed building containing 7,600m2 of research space. Its aim is to bring academics and commercial partners under one roof to explore potential applications for graphene. The facilities will allow the development of prototypes that could potentially enter into full production. Commercial partners include BAE and Rolls Royce. Funded by the UK government and the European Regional Development Fund, the NGI is one of the most advanced research laboratories targeting graphene and other two-dimensional materials (one-atom thick). The building is designed for use by 200 researchers and includes laser, optical, metrology and chemical laboratories. It has offices, seminar rooms and two cleanrooms (spaces with very low levels of contaminants), including one that takes up the whole lower ground floor. Carrying out research at an atomic level requires highly controlled environments. As well as being clear of contaminants, temperatures must be stable and rooms free from vibration, magnetic and noise interference. The facility also has huge energy requirements – the heat gains from the vacuum pumps, fans and magnets, servicing the specialist equipment is 3-400W/m2. The cost of the services accounts for 50% of the construction cost, which gives you an indication of the scale of the challenge faced by the MEP designer. 

== Laboratory design ==

The scale and sophistication of the building services and the required power and cooling capacities for research are similar to those found in industrial research and manufacturing facilities. Capabilities to achieve power distribution for research equipment alone in excess of 200W/m2 result in the potential for large cooling loads. The system is designed so that any space can have environmental cooling for occupants or process cooling for equipment, where it is currently built out as a lab or not. The client brief required the cleanroom and labs to accommodate interdisciplinary research, which meant designing flexible spaces that can meet future research needs. The lab spaces are in a modularised structural grid, which allows the floor area to be reconfigured into specialised zones or open-plan research space. Process service distribution is through a fixed spine in each floor plate. Standard lab zones have two recirculation air-handling units capable of meeting the high room gains. Control can be done per lab module in parallel or master slave, or by grouped control if labs are opened up. Centralised make-up air is provided to compensate for the three segregated process extraction systems that remove solvents, gases and general fumes. The exhaust from fume cabinets, wet decks and other ancillary exhausts are considerable, and the systems are designed to remove and treat up to 24m3/s of exhaust. As such, the make-up air plants are extensive, with a cleanroom plant including pressurisation capacity of 27m3/s and a laboratory make-up air and supply system capable of supplying 11m3/s and recirculating up to 7m3/s. Heat recovery run-around coils were installed between the process exhaust streams and

makeup air handling units. The centralised plants control relative humidity within the labs and cleanroom to 45%+/-5%.

== Cleanrooms ==

The centrepieces of the facility are the 1,500m2 cleanrooms at basement and first floor level. These are configured as a bay and chase layout on a raised floor construction. In this arrangement, the clean bay area contains the process tools and equipment, and clean air is supplied downward from the ceiling mounted FFU (fan filter unit). The air passes into the room through the raised floor and then recirculates up through the adjacent clean bay chase. The cleanrooms consist of three main areas: the 1 metre deep raised floor, the 3 metre high cleanroom and finally the plenum space which is 4 metres at its highest point. The plenum height is required to contain the numerous service and ducts. Air inside the plenum is pushed down into the cleanroom. Facilities are interconnected by dedicated clean stairs and clean lifts. The lift is fitted out to cleanroom material standards – the lift shaft is epoxy coated, the car has fan filter units in the roof and the shaft is at a negative pressure with respect to doors, landing and adjacent areas. Bays are linked by a work-in-process corridor allowing easy inter-disciplinary movement between shared facilities. The basement area cleanrooms are currently fitted out with a combination of ISO 5/6 (Class 1,00/1000), which means air must contain no more than 100 particles (0.5 microns or larger) per cubic foot of air for ISO 5 and 1000 particles for ISO 6. By comparison, air in a typical office contains between 500,000 to 1,000,000 particles (0.5 microns or larger) per cubic foot of air, so the least contaminated NGI spaces are 10,000 times cleaner. The 400m2 first-floor cleanroom provides an ISO 6 (Class 1000) space which can be adapted to improve cleanliness if required. The clean air management system has programmable variable speed control, allowing individual spaces to be tailored to the research demands and night time set-back of air flows while still maintaining cleanliness levels. This ensures energy use and room cooling is minimised throughout its lifecycle. Additionally, the cleanrooms have to comply with stringent vibration criteria of VC-D at the basement level and VC-B on the first-floor area. Rigorous vibration control is essential for research at an atomic level. Extensive design effort was made to isolate the main mechanical, process services and electrical plant from the sensitive laboratory spaces in a structurally independent central utility block (CUB). Not one, but two frames were acoustically and structurally isolated from the main building via a 50mm isolation joint.

The smaller frame contains plant equipment while the second houses the principal laboratory, cleanroom and office accommodation. Specialist and electrical services Contained within the main clean space is a suite of microscopy rooms, each with individual air temperature controls capable of maintaining +/- 0.1K over periods of 12 minutes. Increased acoustic attenuation is provided to mitigate potential noise contamination of the scientific measurements which are completed in this suite.

Facilities such as NGI cannot exist without special services that integrate with

scientific equipment. Providing for these services, emergency power, early smoke detection and security systems means there are more than 75 different HVAC, electrical and process flow systems and streams covering 3,000m2 of laboratories, cleanrooms and support space. The electrical services follow some of the traditional laboratory and cleanroom approaches by dedicating and separating power by research lab or cell. This also requires specialist earthing systems for each laboratory. A total diversified power load of over 3MW is required to serve the research demands as well as the cooling and HVAC plant powerrequirements. All systems are backed up by a standby generator.

== The benefits of BIM ==

The complexity of the services required for cleanrooms, labs and support spaces within a restricted building footprint made BIM invaluable on the project, and a fully federated model was prepared to ensure the usable research space was maximised. Clash detection meetings and reviews between consultants and subcontractors occurred every two weeks when the team identified and resolved the main clash points. An example of the benefits of this ongoing dialogue was a problem relating to the footing of a 12-tonne roof mounted extraction unit that was overlapping the movement joint and had the potential to cause vibrations throughout the building. Had BIM not highlighted this, the contractor estimated it would have cost in excess of £30,000 to rectify the issue. Research facilities such as NGI are highenergy users, and it is a big challenge to minimise unregulated and regulated carbon. This starts with passive elements such as the form and façade, which reduce heat gains in research spaces using lots of power. The demands of low/zero carbon technology and Part L compliance has meant that sustainable engineered solutions are a cornerstone of the project. High efficiency plants, equipment and motors, low energy filters and variable volume flow systems were specified and there is extensive monitoring and automatic controls. Although the plant was designed with a standalone capability, the long-term intention is to integrate the primary energy supply onto the University of Manchester’s steam distribution infrastructure fuelled by waste heat from proposed CHP developments. With a view to this, the high-efficiency aircooled central chiller plant has been designed with a lead absorption chiller utilising this waste heat to provide up to 900kW of base load cooling requirements for the facility. Much of this cooling can be used at night and weekends as the facility requires continual operation of the cleanroom and process cooling water plant for research equipment. There is also a 17kW array of photovoltaic cells, which helped the building to achieve a BREEAM rating of very good, along with the wild meadow garden terrace and selection of sustainable building materials and methods. The university believes graphene’s potential will best be developed by creating a second dedicated building, and CH2M is designing the MEP services for the £60m Graphene Engineering Innovation Centre (GEIC), which is designed to progress the research of NGI from technology readiness (TR) level 2 to TR levels 3-6 in the GEIC. Due to open in 2017, the 8,400m2 facility will be used to develop industryled applications into prototype and early production. It will also help to consolidate Manchester’s global position in graphene research, and help the university live up to its claim of being the home of graphene.

== Avoiding magnetic interference ==

The equipment necessary for research into atom particles, such as electron beam machinery, is very sensitive to magnetic interference. Some of the equipment is so sensitive to magnetic fields that the turning of a metal handle can skew results. To prevent/minimise interference of sensitive electromagnetic equipment, their metals have to be designed out within a 5m radius. This means that re-bars in some areas are made from stainless steel rather than ferrous steel. If rooms are small, faraday shields have to be built into adjoining spaces to ensure the magnetic field is not disturbed. The control gear required for LEDs has to be moved out of plenum spaces because of their high magnetic fields.

== Built-in resilience ==

Resilience was a key requirement in terms of future proofing the building and ensuring research is never lost. All major plant has redundancy built in with spare air-handling units, chiller, transformer, pumps and fans.

More specialised systems include leak detection, gas detection and monitoring, aspirated smoke detection (necessary due to high air change rates), and extensive telecom/data systems including more than 100km of Cat 6a cabling. The facility was designed to be able to adapt to new 2D material research as well as research on graphene. The building is highly modularised to allow spaces to change and reflect new areas of research. The process and HVAC services are universally distributed from the CUB to meet the primary demands of each space. The spaces are built at a scale that allows secondary systems, such as recirculation cooling, to be added or modified in each laboratory. Plant areas share access to the 3,000kg goods lift, which was sized and planned for delivery of scientific equipment, and there is plant maintenance access at 3.0 x 4.0m with a 2.7m door opening height.

The through and-through lift opens on each floor to the individual plant spaces as well as the access corridors serving the labs and cleanrooms. Although the NGI was an exceptionally tight build, which used 100% of the site curtilage, main distribution headers and cable trays have been installed with some flexibility to allow for higher capacity. Gas and process pipe racks were spaced and coordinated to allow capacity for additional future services. Consideration was also given to the potential future addition of a helium bulk storage tank and basement helium recovery plant to meet the cryogenic research demands of graphene.

== Specialist Services ==

Scientific specifications required by NGI
*Compressed air quality complying with standard ISO 8573-1:2010 [1:1:1]
*High purity 99.999% pure bulk nitrogen gas
*Process vacuum for handling systems
*American Society for Testing and Materials (ASTM) D5127 Class E-1 standard for ultra-pure water
*Waste water drainage and collection system
*Twenty-three separate high-purity process gases (pyrophoric, flammable, toxic and inert)

== Project Team ==
*Client: University Of Manchester
*Technical architect and M&E consultant: CH2M HILL
*Building architect: Jestico + Whiles
*Main contractor: BAM Construct
*Structural engineer: Ramboll
*Project manager & QS: EC Harris
*CDM cordinator: Keelagher Okey Klein
*Approved building inspector: HCD

For the full article on the CIBSE website click here.

National Graphene Institute

2015-11-05T10:53:13Z

CIBSE: Created page with " Article from the November 2015 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Ian MacAskill. The first big breakthrough in graphene took plac..."

Article from the November 2015 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Ian MacAskill. 

The first big breakthrough in graphene took place in Manchester, and now the city has a £61m facility aimed at developing the material for everyday use. CH2M Hill’s Ian MacAskill describes the challenge of designing services for the extraordinarily complex National Graphene Institute. In 2004, two professors at the University of Manchester Andre Geim and Kostya Novoselov isolated graphene, and such is the fascination with the possibilities and properties of graphene, they wereawarded the Nobel Prize for Physics in 2010. Graphene is the world’s thinnest material and even though it’s only one-atom thick, it is 200 times stronger than steel and its superior strength, conductivity, stiffness and transparency mean its revolutionary properties have applications in electronics, energy and medicine. To capitalise on the work done by Geim and Novoselov, the University of Mancheseter has built a £61m state-of-the-art laboratory dedicated to the research and commercial development of graphene. The National Graphene Institute (NGI), designed by Jestico + Whiles is a five-storey glazed building containing 7,600m2 of research space. Its aim is to bring academics and commercial partners under one roof to explore potential applications for graphene. The facilities will allow the development of prototypes that could potentially enter into full production. Commercial partners include BAE and Rolls Royce. Funded by the UK government and the European Regional Development Fund, the NGI is one of the most advanced research laboratories targeting graphene and other two-dimensional materials (one-atom thick). The building is designed for use by 200 researchers and includes laser, optical, metrology and chemical laboratories. It has offices, seminar rooms and two cleanrooms (spaces with very low levels of contaminants), including one that takes up the whole lower ground floor. Carrying out research at an atomic level requires highly controlled environments. As well as being clear of contaminants, temperatures must be stable and rooms free from vibration, magnetic and noise interference. The facility also has huge energy requirements – the heat gains from the vacuum pumps, fans and magnets, servicing the specialist equipment is 3-400W/m2. The cost of the services accounts for 50% of the construction cost, which gives you an indication of the scale of the challenge faced by the MEP designer. 

== Laboratory design ==

The scale and sophistication of the building services and the required power and cooling capacities for research are similar to those found in industrial research and manufacturing facilities. Capabilities to achieve power distribution for research equipment alone in excess of 200W/m2 result in the potential for large cooling loads. The system is designed so that any space can have environmental cooling for occupants or process cooling for equipment, where it is currently built out as a lab or not. The client brief required the cleanroom and labs to accommodate interdisciplinary research, which meant designing flexible spaces that can meet future research needs. The lab spaces are in a modularised structural grid, which allows the floor area to be reconfigured into specialised zones or open-plan research space. Process service distribution is through a fixed spine in each floor plate. Standard lab zones have two recirculation air-handling units capable of meeting the high room gains. Control can be done per lab module in parallel or master slave, or by grouped control if labs are opened up. Centralised make-up air is provided to compensate for the three segregated process extraction systems that remove solvents, gases and general fumes. The exhaust from fume cabinets, wet decks and other ancillary exhausts are considerable, and the systems are designed to remove and treat up to 24m3/s of exhaust. As such, the make-up air plants are extensive, with a cleanroom plant including pressurisation capacity of 27m3/s and a laboratory make-up air and supply system capable of supplying 11m3/s and recirculating up to 7m3/s. Heat recovery

run-around coils were installed between the process exhaust streams and
makeup air handling units. The centralised plants control relative
humidity within the labs and cleanroom to 45%+/-5%.
== Cleanrooms ==

The centrepieces of the facility are the 1,500m2 cleanrooms at basement and first floor level. These are configured as a bay and chase layout on a raised floor construction. In this arrangement, the clean bay area contains the process tools and equipment, and clean air is supplied downward from the ceiling mounted FFU (fan filter unit). The air passes into the room through the raised floor and then recirculates up through the adjacent clean bay chase. The cleanrooms consist of three main areas: the 1 metre deep raised floor, the 3 metre high cleanroom and finally the plenum space which is 4 metres at its highest point. The plenum height is required to contain the numerous service and ducts. Air inside the plenum is pushed down into the cleanroom. Facilities are interconnected by dedicated clean stairs and clean lifts. The lift is fitted out to cleanroom material standards – the lift shaft is epoxy coated, the car has fan filter units in the roof and the shaft is at a negative pressure with respect to doors, landing and adjacent areas. Bays are linked by a work-in-process corridor allowing easy inter-disciplinary movement between shared facilities. The basement area cleanrooms are currently fitted out with a combination of ISO 5/6 (Class 1,00/1000), which means air must contain no more than 100 particles (0.5 microns or larger) per cubic foot of air for ISO 5 and 1000 particles for ISO 6. By comparison, air in a typical office contains between 500,000 to 1,000,000 particles (0.5 microns or larger) per cubic foot of air, so the least contaminated NGI spaces are 10,000 times cleaner. The 400m2 first-floor cleanroom provides an ISO 6 (Class 1000) space which can be adapted to improve cleanliness if required. The clean air management system has programmable variable speed control, allowing individual spaces to be tailored to the research demands and night time set-back of air flows while still maintaining cleanliness levels. This ensures energy use and room cooling is minimised throughout its lifecycle. Additionally, the cleanrooms have to comply with stringent vibration criteria of VC-D at the basement level and VC-B on the first-floor area. Rigorous vibration control is essential for research at an atomic level. Extensive design effort was made to isolate the main mechanical, process services and electrical plant from the sensitive laboratory spaces in a structurally independent central utility block (CUB). Not one, but two frames were acoustically and structurally isolated from the main building via a 50mm isolation joint.

The smaller frame contains plant equipment while the second houses the principal laboratory, cleanroom and office accommodation. Specialist and electrical services Contained within the main clean space is a suite of microscopy rooms, each with individual air temperature controls capable of maintaining +/- 0.1K over periods of 12 minutes. Increased acoustic attenuation is provided to mitigate potential noise contamination of the scientific measurements which are completed in this suite.

Facilities such as NGI cannot exist without special services that integrate with
scientific equipment. Providing for these services, emergency power, early smoke detection and security systems means there are more than 75 different HVAC, electrical and process flow systems and streams covering 3,000m2 of laboratories, cleanrooms and support space. The electrical services follow some of the traditional laboratory and cleanroom approaches by dedicating and separating power by research lab or cell. This also requires specialist earthing systems for each laboratory. A total diversified power load of over 3MW is required to serve the research demands as well as the cooling and HVAC plant powerrequirements. All systems are backed up by a standby generator.

== The benefits of BIM ==

The complexity of the services required for cleanrooms, labs and support spaces within a restricted building footprint made BIM invaluable on the project, and a fully federated model was prepared to ensure the usable research space was maximised. Clash detection meetings and reviews between consultants and subcontractors occurred every two weeks when the team identified and resolved the main clash points. An example of the benefits of this ongoing dialogue was a problem relating to the footing of a 12-tonne roof mounted extraction unit that was overlapping the movement joint and had the potential to cause vibrations throughout the building. Had BIM not highlighted this, the contractor estimated it would have cost in excess of £30,000 to rectify the issue. Research facilities such as NGI are highenergy users, and it is a big challenge to minimise unregulated and regulated carbon. This starts with passive elements such as the form and façade, which reduce heat gains in research spaces using lots of power. The demands of low/zero carbon technology and Part L compliance has meant that sustainable engineered solutions are a cornerstone of the project. High efficiency plants, equipment and motors, low energy filters and variable volume flow systems were specified and there is extensive monitoring and automatic controls. Although the plant was designed with a standalone capability, the long-term intention is to integrate the primary energy supply onto the University of Manchester’s steam distribution infrastructure fuelled by waste heat from proposed CHP developments. With a view to this, the high-efficiency aircooled central chiller plant has been designed with a lead absorption chiller utilising this waste heat to provide up to 900kW of base load cooling requirements for the facility. Much of this cooling can be used at night and weekends as the facility requires continual operation of the cleanroom and process cooling water plant for research equipment. There is also a 17kW array of photovoltaic cells, which helped the building to achieve a BREEAM rating of very good, along with the wild meadow garden terrace and selection of sustainable building materials and methods. The university believes graphene’s potential will best be developed by creating a second dedicated building, and CH2M is designing the MEP services for the £60m Graphene Engineering Innovation Centre (GEIC), which is designed to progress the research of NGI from technology readiness (TR) level 2 to TR levels 3-6 in the GEIC. Due to open in 2017, the 8,400m2 facility will be used to develop industryled applications into prototype and early production. It will also help to consolidate Manchester’s global position in graphene research, and help the university live up to its claim of being the home of graphene.

== Avoiding magnetic interference ==

The equipment necessary for research into atom particles, such as electron beam machinery, is very sensitive to magnetic interference. Some of the equipment is so sensitive to magnetic fields that the turning of a metal handle can skew results. To prevent/minimise interference of sensitive electromagnetic equipment, their metals have to be designed out within a 5m radius. This means that re-bars in some areas are made from stainless steel rather than ferrous steel. If rooms are small, faraday shields have to be built into adjoining spaces to ensure the magnetic field is not disturbed. The control gear required for LEDs has to be moved out of plenum spaces because of their high magnetic fields.

== Built-in resilience ==

Resilience was a key requirement in terms of future proofing the building and ensuring research is never lost. All major plant has redundancy built in with spare air-handling units, chiller, transformer, pumps and fans.

More specialised systems include leak detection, gas detection and monitoring, aspirated smoke detection (necessary due to high air change rates), and extensive telecom/data systems including more than 100km of Cat 6a cabling. The facility was designed to be able to adapt to new 2D material research as well as research on graphene. The building is highly modularised to allow spaces to change and reflect new areas of research. The process and HVAC services are universally distributed from the CUB to meet the primary demands of each space. The spaces are built at a scale that allows secondary systems, such as recirculation cooling, to be added or modified in each laboratory. Plant areas share access to the 3,000kg goods lift, which was sized and planned for delivery of scientific equipment, and there is plant maintenance access at 3.0 x 4.0m with a 2.7m door opening height. The through and-through lift opens on each floor to the individual plant spaces as well as the access corridors serving the labs and cleanrooms. Although the NGI was an exceptionally tight build, which used 100% of the site curtilage, main distribution headers and cable trays have been installed with some flexibility to allow for higher capacity. Gas and process pipe racks were spaced and coordinated to allow capacity for additional future services. Consideration was also given to the potential future addition of a helium bulk storage tank and basement helium recovery plant to meet the cryogenic research demands of graphene.

== Specialist Services ==

Scientific specifications required by NGI
*Compressed air quality complying with standard ISO 8573-1:2010 [1:1:1]
*High purity 99.999% pure bulk nitrogen gas
*Process vacuum for handling systems
*American Society for Testing and Materials (ASTM) D5127 Class E-1 standard for ultra-pure water
*Waste water drainage and collection system
*Twenty-three separate high-purity process gases (pyrophoric, flammable, toxic and inert)

== Project Team ==
*Client: University Of Manchester
*Technical architect and M&E consultant: CH2M HILL
*Building architect: Jestico + Whiles
*Main contractor: BAM Construct
*Structural engineer: Ramboll
*Project manager & QS: EC Harris
*CDM cordinator: Keelagher Okey Klein
*Approved building inspector: HCD

University of East London’s new library in Stratford

2015-10-08T16:12:42Z

CIBSE:

Article from the October 2015 edition of the [http://www.cibsejournal.com CIBSE Journal] by Andy Pearson.

Soft landings is instrumental in helping Aecom target tough energy requirements for the University of East London’s new library in Stratford. Find out how continual refinement of the building, once in operation, helped it win CIBSE’s New Build Project of the Year (up to £10m) award. The University of East London’s brief to Hopkins Architects and services consultant Aecom was clear: design a new library for its Stratford campus that would meet its exacting sustainability agenda and extremely low operational energy targets. 

Its brief set an annual energy target of 100kWh/m2 for both regulated and unregulated energy consumption, including small power and IT systems, for the new threestorey building. ‘It was quite a tight target for a library open 24seven,’ says Sara Kassam, CIBSE’s head of sustainability development, who – at the time – was UEL’s sustainability manager and one of the team responsible for setting the energy standards that were integral to this challenging brief. 

To put the target into context: the Elizabeth Fry Building, widely recognised as one of the most energy efficient university buildings in the UK, has an annual energy use of 98.8kWh/m2 based on a daytime, weekday occupancy. ‘The building we set out to design was effectively operating three times longer than the building we were trying to match it against,’ says Martin McLaughlin, a regional director at Aecom. Aecom’s solution for the £8.6m scheme has been to develop a demandled building services design, which – according to McLaughlin – means energyconsuming plant ‘is only ever on when it is needed’. It is a solution that is starting to reap rewards; the building is still undergoing intensive finetuning as part of its soft landings programme but currently its annual energy consumption is 164kWh/m2. 

The design team’s efforts were recognised at this year’s CIBSE Building Performance Awards, where the scheme won the New Build Project of the Year (for schemes with a value of up to £10m) category. The judges described the scheme as ‘A fantastic achievement for a very complicated project with clear and ambitious targets’. The starting point in the development of the low energy design for the 4,200m2 library was in gaining an understanding of how the new building was likely to be used at different times of the day throughout a year. ‘Having an in-use energy target meant that we had to understand occupational use,’ explains McLaughlin. 

Fortunately the university had occupancy data for the campus’s current library. This showed, as expected, that the number of students using the library dropped significantly overnight, but that there were still sufficient students present and equipment operating to create a small services demand. ‘The risk with this is that if you put up a simple building that operates with simple controls, there is a danger that all the lights will be switched on and all the plant will run,’ McLaughlin says. ‘Developing a demandbased solution meant that actual operational loads could be minimised by operating plant only when it is needed’. 

A demand-led displacement ventilation system keeps the building supplied with fresh air through an underfloor variable air volume (VAV) system. To ensure the system can cope with occupancy levels, which vary from several hundred during the day to as few as 15 insomniacs dotted about the three-storey library at night, the floor plates have been sub-divided into 6m by 6m ventilation cells. 

Each cell has its own VAV box, complete with temperature and carbon dioxide sensors to control the quantity of fresh air supplied to the cell. ‘This system ensures that at night, ventilation to each cell can be shut off unless the controls say it is needed,’ explains McLaughlin. Cooling, for example will only be provided to a particular zone when it is occupied and when its temperature rises above the set-point. Air returns from the floors to four roofmounted air handling units (AHUs) via the building’s central light well – a duct-free solution that helps eliminate duct friction losses to keep fan power to a minimum. 

The AHUs have been selected to minimise energy consumption. ‘We opted for a bigger air handling box to keep air speeds and specific fan powers low, which is important for a fan that will operate 24-seven,’ says McLaughlin. In addition to their generous dimensions, each AHU is fitted with a mixing box controlled by a CO2 sensor to maximise recirculation of treated air and minimise the energy needed for treating fresh air. Heat is also recovered from the exhaust air by a thermal wheel. 

‘During the day the library is very heavily occupied so we set the units up with the best possible set-point for energy efficiency, meaning the CO2 level is at the higher end of the acceptable range, but with the option of the university switching to a lower CO2 setting using the building management system, if the library starts to feel stuffy,’ McLaughlin explains. 

To help keep the building cool, the AHUs incorporate a cooling coil. ‘Because we’re using a displacement ventilation system, it means the chillers can make use of free cooling for the 85% of the year when the outside temperature is below 18°C.’ The design team did look at other cooling options, including an underground thermal labyrinth and a TermoDeck-type solution, where the supply air passes through hollow-core floor planks. These were developed and analysed with a lifecycle costing analysis undertaken to develop the solution. The university’s facilities team involved with system selection as part of the soft landings pre-construction review, dismissed both systems. 

The TermoDeck solution wasn’t taken forward for energy and flexibility reasons, and the labyrinth solution wasn’t pursued because of both cost and maintenance reasons. The maintenance team was concerned about keeping the air shaft and labyrinth clean and maintaining good fresh air quality with a low level air intake that would have to be located in the main students courtyard. The designers also looked at natural and stack ventilation-based solutions and a mixed mode option but, after a detailed energy appraisal, the demand controlled solution using big AHUs still proved the most energy efficient option. 

To keep plant operation to a minimum, the rectangular building has been designed as a tightly sealed, insulated box. Every element of the building’s fabric has been designed to be more energy efficient than the minimum standards demanded by Part L (see panel ‘Stratford Library fabric U-values’). In addition, fabric air leakage was measured at a meagre 2.9m3/hr/m2 at 50Pa (far lower than the 10m3/hr/m2 at 50Pa permitted under Part L of the Building Regulations). ‘Because of the 24-hour operation we don’t have to heat the building quickly, or cool it back down again, because we’ve designed it to be kept at a steady temperature,’ McLaughlin says. Thermal mass provided by the building’s exposed concrete soffits and reinforced concrete frame help to minimise internal temperature fluctuations further. For most of the year the soffits help moderate temperatures by absorbing heat during the day, when occupancy, solar gains and small power loads are at their peak; this heat is then released back to the space at night, when heat gains and occupancy are reduced. 

The only exception to this method of operation is during the summer break, when the library closes at night; the system will then operate on a night-ventilation strategy, purging the concrete of excess heat to recharge the thermal mass. In winter, two gas-fired condensing boilers provide space heating for when temperatures drop below -1°C. The boilers feed a series of trench heating coils, which have been set into the base of the window reveals. The boilers also supply heat to the hot water system thermal stores through a plate heat exchanger, which helps keep the boiler return water temperature low enough to ensure the boilers run in full condensing mode to maximise their energy efficiency. 

In addition to the design of the heating and ventilation systems, the designers also followed the demand-led approach to reduce lighting and small power loads. ‘When we looked at the initial energy appraisal for the building, a big chunk of energy use sat with small power and lighting,’ says McLaughlin. He said that a mixture of high frequency T5 lighting and LED’s were used throughout the building. 

Rather than use high levels of illumination across the floors, the team opted for the lower energy solution of using task lighting focused on the bookshelves and desks, supplemented by minimal background lighting. In keeping with the demand-led approach, all light fittings incorporate presence detectors, while light fittings around the building’s perimeter and atrium additionally incorporate daylight sensors to make the most of natural light. 

The building’s electrical supply is supplemented by a 409m2 area of photovoltaic panels covering its roof. These are expected to provide 55,075 kWh/y of electricity, giving a present value payback in the range of 11-16 years. To keep IT power loads to a minimum, the university’s IT team worked hard to incorporate energy saving features into the building’s PCs. In addition, IT server rooms are cooled using outside air blown into the room by a fan. In winter, this warmed air is used to provide additional heating to the library, while in summer it is returned outside. Only when the outside temperature rises above 25°C does a DX cooling system start to operate. 

A soft landings engineer (SLE) was engaged during construction and, prior to commissioning, to witness development of the controls and metering strategy. The SLE worked closely with the sub-contractors and project specialists to lead the client training sessions ensuring that, on handover, the UEL team was familiar with the building’s engineering systems. Following the June 2013 handover, a post-completion soft landings monitoring programme was established to help fine tune the systems and achieve the client’s 100kWh/y/m2 target. When the scheme opened, for the first two weeks engineers were based on site two days a week, and one day a week for the following month to help optimise the systems in operation. 

After the initial six weeks, the soft landings project was continued with monthly on-site meetings for the remainder of the first year of operation. The engineers’ continued presence has allowed the design team to adjust the services in response to use and performance. For example, the library’s night time occupancy has been lower than expected, which has allowed the operations team to shut down the building’s top floor at night, saving further energy. 

The soft landings team’s job has been even more challenging because of problems with some of the sub-meters, which meant the total energy from the sub-meters failed to equal the total energy consumed on the main meter. ‘We had challenges around sub-metering, which were due to a couple of meters giving incorrect readings,’ explains McLaughlin. This has now been resolved. The soft landings team also found that the library’s energy consumption was higher than expected. One reason for this was found to have been down to the CO2 set point in one of the VAV boxes having been adjusted from the original position. ‘In future we will strongly advocate that there is a BMS head-end screen that gives a detailed explanation as to why each particular set point is important, what its operating range should be, and the likely impact of adjusting the setting operational energy use,’ McLaughlin says. 

Currently the BREEAM Excellent scheme is consuming 164kWh/y/m2. When compared to the original design predictions, actual use has delivered 54% less lighting kWh, 63% less small power kWh, and the server rooms have consumed 80% less energy for both IT and cooling. However, the mechanical systems are consuming more energy than expected, which will require a further period of controls finetuning to match the building’s services to its operation to meet the clients target of 100kWh/y/m2. Aecom’s building performance awards hat-trick In addition to winning the New Build Project of the Year (value up to £10m) category, Aecom also scooped the Collaborative Working Partnership and the Building Services Consultancy of the Year (over 100 employees) awards. The Collaborative Working award went to Aecom’s team working with the BBC on the transformation of Broadcasting House in London. The judges said: ‘The team did so much and achieved a great result.’ The Building Services Consultancy award went to Aecom for its provision of a broad range of consultancy and sustainability services, its commitment to training development of its workforce and its investment in research. The judges said Aecom had submitted ‘a comprehensive submission that provided really good examples of building performance'. Project Team 
*Client: University of East London 
*Architect: Hopkins Architects
*Building services engineer:Aecom
*Project manager: JLL
*QS: Turner and Townsend
*Contractor: Volker Fitzpatrick

To read this article on the --[http://www.designingbuildings.co.uk/wiki/User:CIBSE CIBSE] website, please click [http://www.cibse.org/knowledge/building-services-case-studies here].

University of East London’s new library in Stratford

2015-10-08T16:10:39Z

CIBSE:

Article from the October 2015 edition of the [http://www.cibsejournal.com CIBSE Journal] by Andy Pearson.

Soft landings is instrumental in helping Aecom target tough energy requirements for the University of East London’s new library in Stratford. Find out how continual refinement of the building, once in operation, helped it win CIBSE’s New Build Project of the Year (up to £10m) award. The University of East London’s brief to Hopkins Architects and services consultant Aecom was clear: design a new library for its Stratford campus that would meet its exacting sustainability agenda and extremely low operational energy targets. 

Its brief set an annual energy target of 100kWh/m2 for both regulated and unregulated energy consumption, including small power and IT systems, for the new threestorey building. ‘It was quite a tight target for a library open 24seven,’ says Sara Kassam, CIBSE’s head of sustainability development, who – at the time – was UEL’s sustainability manager and one of the team responsible for setting the energy standards that were integral to this challenging brief. 

To put the target into context: the Elizabeth Fry Building, widely recognised as one of the most energy efficient university buildings in the UK, has an annual energy use of 98.8kWh/m2 based on a daytime, weekday occupancy. ‘The building we set out to design was effectively operating three times longer than the building we were trying to match it against,’ says Martin McLaughlin, a regional director at Aecom. Aecom’s solution for the £8.6m scheme has been to develop a demandled building services design, which – according to McLaughlin – means energyconsuming plant ‘is only ever on when it is needed’. It is a solution that is starting to reap rewards; the building is still undergoing intensive finetuning as part of its soft landings programme but currently its annual energy consumption is 164kWh/m2. 

The design team’s efforts were recognised at this year’s CIBSE Building Performance Awards, where the scheme won the New Build Project of the Year (for schemes with a value of up to £10m) category. The judges described the scheme as ‘A fantastic achievement for a very complicated project with clear and ambitious targets’. The starting point in the development of the low energy design for the 4,200m2 library was in gaining an understanding of how the new building was likely to be used at different times of the day throughout a year. ‘Having an in-use energy target meant that we had to understand occupational use,’ explains McLaughlin. 

Fortunately the university had occupancy data for the campus’s current library. This showed, as expected, that the number of students using the library dropped significantly overnight, but that there were still sufficient students present and equipment operating to create a small services demand. ‘The risk with this is that if you put up a simple building that operates with simple controls, there is a danger that all the lights will be switched on and all the plant will run,’ McLaughlin says. ‘Developing a demandbased solution meant that actual operational loads could be minimised by operating plant only when it is needed’. 

A demand-led displacement ventilation system keeps the building supplied with fresh air through an underfloor variable air volume (VAV) system. To ensure the system can cope with occupancy levels, which vary from several hundred during the day to as few as 15 insomniacs dotted about the three-storey library at night, the floor plates have been sub-divided into 6m by 6m ventilation cells. 

Each cell has its own VAV box, complete with temperature and carbon dioxide sensors to control the quantity of fresh air supplied to the cell. ‘This system ensures that at night, ventilation to each cell can be shut off unless the controls say it is needed,’ explains McLaughlin. Cooling, for example will only be provided to a particular zone when it is occupied and when its temperature rises above the set-point. Air returns from the floors to four roofmounted air handling units (AHUs) via the building’s central light well – a duct-free solution that helps eliminate duct friction losses to keep fan power to a minimum. 

The AHUs have been selected to minimise energy consumption. ‘We opted for a bigger air handling box to keep air speeds and specific fan powers low, which is important for a fan that will operate 24-seven,’ says McLaughlin. In addition to their generous dimensions, each AHU is fitted with a mixing box controlled by a CO2 sensor to maximise recirculation of treated air and minimise the energy needed for treating fresh air. Heat is also recovered from the exhaust air by a thermal wheel. 

‘During the day the library is very heavily occupied so we set the units up with the best possible set-point for energy efficiency, meaning the CO2 level is at the higher end of the acceptable range, but with the option of the university switching to a lower CO2 setting using the building management system, if the library starts to feel stuffy,’ McLaughlin explains. 

To help keep the building cool, the AHUs incorporate a cooling coil. ‘Because we’re using a displacement ventilation system, it means the chillers can make use of free cooling for the 85% of the year when the outside temperature is below 18°C.’ The design team did look at other cooling options, including an underground thermal labyrinth and a TermoDeck-type solution, where the supply air passes through hollow-core floor planks. These were developed and analysed with a lifecycle costing analysis undertaken to develop the solution. The university’s facilities team involved with system selection as part of the soft landings pre-construction review, dismissed both systems. 

The TermoDeck solution wasn’t taken forward for energy and flexibility reasons, and the labyrinth solution wasn’t pursued because of both cost and maintenance reasons. The maintenance team was concerned about keeping the air shaft and labyrinth clean and maintaining good fresh air quality with a low level air intake that would have to be located in the main students courtyard. The designers also looked at natural and stack ventilation-based solutions and a mixed mode option but, after a detailed energy appraisal, the demand controlled solution using big AHUs still proved the most energy efficient option. 

To keep plant operation to a minimum, the rectangular building has been designed as a tightly sealed, insulated box. Every element of the building’s fabric has been designed to be more energy efficient than the minimum standards demanded by Part L (see panel ‘Stratford Library fabric U-values’). In addition, fabric air leakage was measured at a meagre 2.9m3/hr/m2 at 50Pa (far lower than the 10m3/hr/m2 at 50Pa permitted under Part L of the Building Regulations). ‘Because of the 24-hour operation we don’t have to heat the building quickly, or cool it back down again, because we’ve designed it to be kept at a steady temperature,’ McLaughlin says. Thermal mass provided by the building’s exposed concrete soffits and reinforced concrete frame help to minimise internal temperature fluctuations further. For most of the year the soffits help moderate temperatures by absorbing heat during the day, when occupancy, solar gains and small power loads are at their peak; this heat is then released back to the space at night, when heat gains and occupancy are reduced. 

The only exception to this method of operation is during the summer break, when the library closes at night; the system will then operate on a night-ventilation strategy, purging the concrete of excess heat to recharge the thermal mass. In winter, two gas-fired condensing boilers provide space heating for when temperatures drop below -1°C. The boilers feed a series of trench heating coils, which have been set into the base of the window reveals. The boilers also supply heat to the hot water system thermal stores through a plate heat exchanger, which helps keep the boiler return water temperature low enough to ensure the boilers run in full condensing mode to maximise their energy efficiency. 

In addition to the design of the heating and ventilation systems, the designers also followed the demand-led approach to reduce lighting and small power loads. ‘When we looked at the initial energy appraisal for the building, a big chunk of energy use sat with small power and lighting,’ says McLaughlin. He said that a mixture of high frequency T5 lighting and LED’s were used throughout the building. 

Rather than use high levels of illumination across the floors, the team opted for the lower energy solution of using task lighting focused on the bookshelves and desks, supplemented by minimal background lighting. In keeping with the demand-led approach, all light fittings incorporate presence detectors, while light fittings around the building’s perimeter and atrium additionally incorporate daylight sensors to make the most of natural light. 

The building’s electrical supply is supplemented by a 409m2 area of photovoltaic panels covering its roof. These are expected to provide 55,075 kWh/y of electricity, giving a present value payback in the range of 11-16 years. To keep IT power loads to a minimum, the university’s IT team worked hard to incorporate energy saving features into the building’s PCs. In addition, IT server rooms are cooled using outside air blown into the room by a fan. In winter, this warmed air is used to provide additional heating to the library, while in summer it is returned outside. Only when the outside temperature rises above 25°C does a DX cooling system start to operate. 

A soft landings engineer (SLE) was engaged during construction and, prior to commissioning, to witness development of the controls and metering strategy. The SLE worked closely with the sub-contractors and project specialists to lead the client training sessions ensuring that, on handover, the UEL team was familiar with the building’s engineering systems. Following the June 2013 handover, a post-completion soft landings monitoring programme was established to help fine tune the systems and achieve the client’s 100kWh/y/m2 target. When the scheme opened, for the first two weeks engineers were based on site two days a week, and one day a week for the following month to help optimise the systems in operation. 

After the initial six weeks, the soft landings project was continued with monthly on-site meetings for the remainder of the first year of operation. The engineers’ continued presence has allowed the design team to adjust the services in response to use and performance. For example, the library’s night time occupancy has been lower than expected, which has allowed the operations team to shut down the building’s top floor at night, saving further energy. 

The soft landings team’s job has been even more challenging because of problems with some of the sub-meters, which meant the total energy from the sub-meters failed to equal the total energy consumed on the main meter. ‘We had challenges around sub-metering, which were due to a couple of meters giving incorrect readings,’ explains McLaughlin. This has now been resolved. The soft landings team also found that the library’s energy consumption was higher than expected. One reason for this was found to have been down to the CO2 set point in one of the VAV boxes having been adjusted from the original position. ‘In future we will strongly advocate that there is a BMS head-end screen that gives a detailed explanation as to why each particular set point is important, what its operating range should be, and the likely impact of adjusting the setting operational energy use,’ McLaughlin says. 

Currently the BREEAM Excellent scheme is consuming 164kWh/y/m2. When compared to the original design predictions, actual use has delivered 54% less lighting kWh, 63% less small power kWh, and the server rooms have consumed 80% less energy for both IT and cooling. However, the mechanical systems are consuming more energy than expected, which will require a further period of controls finetuning to match the building’s services to its operation to meet the clients target of 100kWh/y/m2. Aecom’s building performance awards hat-trick In addition to winning the New Build Project of the Year (value up to £10m) category, Aecom also scooped the Collaborative Working Partnership and the Building Services Consultancy of the Year (over 100 employees) awards. The Collaborative Working award went to Aecom’s team working with the BBC on the transformation of Broadcasting House in London. The judges said: ‘The team did so much and achieved a great result.’ The Building Services Consultancy award went to Aecom for its provision of a broad range of consultancy and sustainability services, its commitment to training development of its workforce and its investment in research. The judges said Aecom had submitted ‘a comprehensive submission that provided really good examples of building performance'. Project Team 
*Client: University of East London 
*Architect: Hopkins Architects
*Building services engineer:Aecom
*Project manager: JLL
*QS: Turner and Townsend
*Contractor: Volker Fitzpatrick

University of East London’s new library in Stratford

2015-10-08T10:44:59Z

CIBSE: Created page with " Article from the October 2015 edition of the [http://www.cibsejournal.com CIBSE Journal] by Andy Pearson. "

Article from the October 2015 edition of the [http://www.cibsejournal.com CIBSE Journal] by Andy Pearson.

University of East Anglia Enterprise Centre

2015-09-01T16:22:29Z

CIBSE:

Article from the September 2015 edition of the [http://www.cibsejournal.com CIBSE Journal] by Andy Pearson. 

== Introduction ==

In aiming for Passivhaus the project team at the Enterprise Centre worked to the tightest of parameters leading to the use of 70% bio-based materials, a superairtight envelope and minimal plug loads. Is this the UK’s greenest commercial building? The Enterprise Centre at the University of East Anglia (UEA) in Norwich is targeting BREEAM Outstanding and Passivhaus certification. Designed to last for 100 years, it has been built on a brownfield site using 70% bio-based materials, many of which have been sourced locally. And it exceeds local planning requirements for 10% of the building’s energy to be from renewables, with a 480m2 roof-mounted photovoltaic array, predicted to generate 44MWh a year. 

Consequently, over its lifetime the building’s embodied carbon is predicted to be one quarter that of a conventionally constructed building. This pioneering two-storey 3,400m2 building is the new home for the Adapt Low Carbon Group, which was created to commercialise graduate start-up firms that have grown out of UEA’s world-class environmental sciences. Adapt wanted its new facilities to be an exemplar of sustainability. ‘There is no point in being a lead institution on climate change if we don’t act on our values and build a site that can help mitigate climate change and can cope with its impacts,’ says group CEO John French. The biggest clue to the £11.6m building’s climate mitigation aspirations is its cladding – the building is wrapped in thatch. In a dramatic reinterpretation of the use of this traditional Norfolk roofing material, the thatch is formed of 250mm thick layers of straw set in prefabricated, vertically-hung timber cassettes – a world first according to Morgan Sindall’s senior site manager Ken Bassett. The thatch holds the carbon absorbed by plants photosynthesising for 100 years or so. ‘We recognised thatch would be a good carbon negative local material,’ Bassett explains. The unique cassette system was developed under a single point delivery contract by Morgan Sindall and project architect Architype. The cassettes were thatched horizontally by local thatchers, who were able to carry out the work safely in barns through the winter when traditionally there is very little work for them. ‘Once all the panels were in place, a thatcher came along and dressed the wall with a machine like a large hedge cutter to give the building a haircut,’ says Bassett. The use of cassettes has enabled this traditional material to be installed in much the same way as conventional cladding panels. Significantly, the panels sit outside of the building’s airtightness and insulation line and are not part of the structure. Thatch cladding features on every elevation of this E-shaped building. The building’s form was the result of the need to maximise the amount of daylight. The top and bottom elements of the E are formed by the two main wings, one of which is for teaching, and the other for start-ups. The building is orientated such that the wing façades face north and south. A predominantly transparent block links the wings, in its centre, and forming the middle of the E is a 300-seat auditorium. 

== Achieving CO2 targets ==

The amount of carbon embodied in the building’s thatch cladding cassettes was calculated by Architype using its newly developed Rapiere software, using information taken from the project BIM model. The client set the design team a target of 500kg of emitted CO2 per square metre over the 100-year life of the building. This meant that every material was selected based on an assessment of embodied carbon and cost. ‘Normally I’d look at cost and programme when selecting materials but here it was a complex equation. We had to look holistically to ensure we reached the optimum balance between achieving BREEAM and Passivhaus targets, minimised embodied energy and lifecycle costs while ensuring we met the construction programme,’ explains Bassett. The building’s foundations were one area where the team had to work extremely hard to find an appropriate solution. The building is supported on a glulam timber frame. Originally it was proposed the frame would be supported on small concrete pad foundations and that the building would feature a timber ground floor supported from the glulam columns. However, Morgan Sindall’s geotechnical investigation revealed a site dotted with sinkholes and the remnants of a glacial riverbed. This resulted in the pad proposal being abandoned, along with the timber ground floor, in favour of a 375mm thick concrete raft foundation incorporating three layers of 98% recycled steel reinforcement.

== Not just a cement mix ==

Concrete has a high level of embodied carbon as a result of the use of cement produced by heating Portland stone to about 1,400°C. ‘Using 1,000m3 of ordinary concrete for the raft would have knocked the project way off its carbon target,’ Bassett explains. Morgan Sindall worked in partnership with its concrete supplier to produce a mix incorporating ground granulated blast furnace slag, which allowed 70% of the cement to be removed from the mix. In addition, recycled sand and responsibly sourced aggregate were also used. ‘This concrete had 38% embodied carbon when compared to ordinary concrete of a comparable mix,’ proclaims Bassett. The raft was cast on a base of Isoquick polystyrene insulation, positioned on a subbase formed from crushed, recycled basement salvaged from the demolition of a nearby hospital. For this project the manufacturer developed special polystyrene kerb units which not only removed the need for shuttering but, equally importantly, enabled the insulating envelope to continue from under the concrete raft to join up with the insulation in the wall minimising heat losses.

‘The solution worked brilliantly,’ says Bassett. In keeping with the low-carbon philosophy, the raft’s top surface has been ground and polished to save on floor finishes. A carpet had been proposed as a covering for the ground floor; this would have been replaced under UEA’s maintenance strategy every seven years. ‘When we looked at the carbon embedded in using a carpet, it was actually more than was in the raft foundation, so we got rid of the carpet and went for a ground finish,’ says Gareth Selby, an associate at architect Architype. The building’s glulam structural frame is supported by the raft. It was sourced from abroad because there are no commercial-scale glulam makers in the UK. The project does, however, make use of Corsican Pine – sourced from Thetford Forest some 30 miles away – in the construction of internal studwork walls. Timber is also used for construction of the façade brise soleil. Future climate data was generated for this project by EA’s Climate Team for an 87-year period. Using this information, Architype simulated a range of design scenarios in Passivhaus Planning Package (PHPP) to optimise the façade design. The analysis highlighted the need to rethink slightly the allocation of south-facing windows deemed essential by Passivhaus as a source of passive heating, to help limit internal gains. ‘From the analysis we boosted shading slightly by setting the windows further back into the reveals,’ explains Selby. ‘From a future perspective we developed a timber brise soleil, which can be adapted to allow more louvres to be added in the future.’

== Keeping cool ==

While the building’s lightweight construction has helped save on embodied carbon, there were some concerns that its lack of thermal mass could result in the building overheating, even in the current climate. These concerns were mitigated, in part, by floor-to-ceiling heights in excess of 3.3m on both floors which helped create sufficient volume to cope with temperature rises and ensure good daylight levels on the floorplates.

Aided by LED lighting and an intelligent control system this helped keep lighting loads to a minimum and kept the primary energy demand below 120kWh/m2/y. The building is exceptionally airtight, even by Passivhaus standards. ‘We achieved an airtightness of 0.21m3/m2 at 50Pa, which is three times better than needed for Passivhaus compliance, and about 100 times better than is required under Part L,’ laughs Bassett. A demand-led ventilation system controlled by occupancy and CO2 sensors delivers fresh air to keep occupants comfortable. The building has three ventilation plantrooms: one in each wing and one in the central auditorium. Each plantoom houses a Swegon Gold, Passivhaus certified, air handling unit (AHU) incorporating a thermal wheel. Air from AHUs is ducted to the floors and distributed via Trox VAV units mounted in a services distribution bulkhead that doubles as an attenuated return air plenum. Air is extracted from the wings via the toilet blocks (there are no toilet extract fans); extracted air is then passed through the thermal wheel before being discharged to outside. Unusually for a Passivhaus project, the Enterprise Centre does include a small amount of cooling in the 300-seat auditorium to ensure it remains comfortable in summer. This is provided by a small direct expansion system with a cooling coil positioned in the supply air stream and a heat rejection unit situated in the exhaust air steam. ‘We’re using cooling just to peak-lop the fresh air supply temperature in summer because the students will be dressed appropriately for the conditions,’ explains James Hepburn, engineer director at BDP, the project’s services engineer. In the main floor areas there is no cooling. Instead occupants can open the building’s windows to provide ventilation. The ventilation strategy, and other aspects of the scheme, were agreed with the UEA’s estates team, who were involved with the project under its Soft Landings initiative and led by Stuart Thompson, senior design manager at Morgan Sindall. This is a good thing because estates will probably need to be proactive in managing the operation of this highly value engineered ventilation solution and innovative building. Heat for the building comes from the UEA’s district heating system. The heating mains ran close to the building, which was fortunate because heat loss from the spur to the building had to be included in the Passivhaus compliance criteria. A heat interface unit incorporating two heat exchangers, one for the heating and one for the hot water – separates the building from the mains. 

One of the biggest challenges in achieving Passivhaus compliance was the provision of hot water to toilet blocks. This is because standing heat losses from hot water pipes are factored into the PHPP spreadsheet. The form of the building with its two wings meant the losses were so high that hot water in the southern wing, the one furthest from the heat interface unit, had to be provided by point-of-use local electric water heaters. Microbore pipework, which has lower standing heat losses, feeds the remaining hot water outlets. 

As far as minimising embodied carbon goes, Hepburn says: ‘We did a fair amount of research looking at different materials but we were not satisfied with the robustness of alternatives in meeting the building’s 100 year life. The best you can do is install less M&E.’ One of the constraints of Passivhaus is becoming apparent now the building is in use. One challenge of gaining certification is that small power loads are included in the Primary Energy Demand maximum. As a result, the design team spent a lot of time selecting the building’s AV systems and, to keep small power loads to a minimum, the client was keen not to flood the building with electrical sockets. ‘Passivhaus is very challenging because it limits what you can do in terms of computers and catering, which we’re finding a little bit constraining,’ remarks French. Bassett, meanwhile, has submitted his last spreadsheets for carbon emissions from deliveries and from the workforce.

The sheets include all deliveries to site, including such details as where the vehicle was from, miles driven, type of vehicle, and fuel. ‘The threshold was less than 500kg/m2 emitted CO2 over the 100-year life including construction carbon – we think we’ll be 10% below that figure,’ says Adapt’s John French. ‘From my perspective we’ve set a new standard in sustainable architecture and it has not cost the earth’.

== Window of opportunity ==

There is no cooling to the main floor areas. However, when conditions allow, the occupants can open the building’s triple-glazed windows to provide ventilation. A display panel in each room contains two LED lamps, which are illuminated when outside air temperatures are suitable to allow windows to be opened. The CO2 sensors in the room will then detect improved air quality and back off the VAV damper serving that room.

If temperatures are very hot, occupants are encouraged to leave the windows open overnight to allow night ventilation. In winter heating availability is limited and controlled by the BMS. Heat in occupied rooms is provided by ‘tiny’ radiators, each fitted with a TRV. ‘We didn’t want to run the risk of not having heating in these rooms, because the building does not have automatic windows so there is a chance a window could be left open overnight,’ explains Hepburn.

To read this article on the CIBSE website, please click [http://www.cibse.org/knowledge/building-services-case-studies here].

University of East Anglia Enterprise Centre

2015-09-01T16:22:02Z

CIBSE:

Article from the September 2015 edition of the [http://www.cibsejournal.com CIBSE Journal] by Andy Pearson. 

Introduction

In aiming for Passivhaus the project team at the Enterprise Centre worked to the tightest of parameters leading to the use of 70% bio-based materials, a superairtight envelope and minimal plug loads. Is this the UK’s greenest commercial building? The Enterprise Centre at the University of East Anglia (UEA) in Norwich is targeting BREEAM Outstanding and Passivhaus certification. Designed to last for 100 years, it has been built on a brownfield site using 70% bio-based materials, many of which have been sourced locally. And it exceeds local planning requirements for 10% of the building’s energy to be from renewables, with a 480m2 roof-mounted photovoltaic array, predicted to generate 44MWh a year. 

Consequently, over its lifetime the building’s embodied carbon is predicted to be one quarter that of a conventionally constructed building. This pioneering two-storey 3,400m2 building is the new home for the Adapt Low Carbon Group, which was created to commercialise graduate start-up firms that have grown out of UEA’s world-class environmental sciences. Adapt wanted its new facilities to be an exemplar of sustainability. ‘There is no point in being a lead institution on climate change if we don’t act on our values and build a site that can help mitigate climate change and can cope with its impacts,’ says group CEO John French. The biggest clue to the £11.6m building’s climate mitigation aspirations is its cladding – the building is wrapped in thatch. In a dramatic reinterpretation of the use of this traditional Norfolk roofing material, the thatch is formed of 250mm thick layers of straw set in prefabricated, vertically-hung timber cassettes – a world first according to Morgan Sindall’s senior site manager Ken Bassett. The thatch holds the carbon absorbed by plants photosynthesising for 100 years or so. ‘We recognised thatch would be a good carbon negative local material,’ Bassett explains. The unique cassette system was developed under a single point delivery contract by Morgan Sindall and project architect Architype. The cassettes were thatched horizontally by local thatchers, who were able to carry out the work safely in barns through the winter when traditionally there is very little work for them. ‘Once all the panels were in place, a thatcher came along and dressed the wall with a machine like a large hedge cutter to give the building a haircut,’ says Bassett. The use of cassettes has enabled this traditional material to be installed in much the same way as conventional cladding panels. Significantly, the panels sit outside of the building’s airtightness and insulation line and are not part of the structure. Thatch cladding features on every elevation of this E-shaped building. The building’s form was the result of the need to maximise the amount of daylight. The top and bottom elements of the E are formed by the two main wings, one of which is for teaching, and the other for start-ups. The building is orientated such that the wing façades face north and south. A predominantly transparent block links the wings, in its centre, and forming the middle of the E is a 300-seat auditorium. 

== Achieving CO2 targets ==

The amount of carbon embodied in the building’s thatch cladding cassettes was calculated by Architype using its newly developed Rapiere software, using information taken from the project BIM model. The client set the design team a target of 500kg of emitted CO2 per square metre over the 100-year life of the building. This meant that every material was selected based on an assessment of embodied carbon and cost. ‘Normally I’d look at cost and programme when selecting materials but here it was a complex equation. We had to look holistically to ensure we reached the optimum balance between achieving BREEAM and Passivhaus targets, minimised embodied energy and lifecycle costs while ensuring we met the construction programme,’ explains Bassett. The building’s foundations were one area where the team had to work extremely hard to find an appropriate solution. The building is supported on a glulam timber frame. Originally it was proposed the frame would be supported on small concrete pad foundations and that the building would feature a timber ground floor supported from the glulam columns. However, Morgan Sindall’s geotechnical investigation revealed a site dotted with sinkholes and the remnants of a glacial riverbed. This resulted in the pad proposal being abandoned, along with the timber ground floor, in favour of a 375mm thick concrete raft foundation incorporating three layers of 98% recycled steel reinforcement.

== Not just a cement mix ==

Concrete has a high level of embodied carbon as a result of the use of cement produced by heating Portland stone to about 1,400°C. ‘Using 1,000m3 of ordinary concrete for the raft would have knocked the project way off its carbon target,’ Bassett explains. Morgan Sindall worked in partnership with its concrete supplier to produce a mix incorporating ground granulated blast furnace slag, which allowed 70% of the cement to be removed from the mix. In addition, recycled sand and responsibly sourced aggregate were also used. ‘This concrete had 38% embodied carbon when compared to ordinary concrete of a comparable mix,’ proclaims Bassett. The raft was cast on a base of Isoquick polystyrene insulation, positioned on a subbase formed from crushed, recycled basement salvaged from the demolition of a nearby hospital. For this project the manufacturer developed special polystyrene kerb units which not only removed the need for shuttering but, equally importantly, enabled the insulating envelope to continue from under the concrete raft to join up with the insulation in the wall minimising heat losses.

‘The solution worked brilliantly,’ says Bassett. In keeping with the low-carbon philosophy, the raft’s top surface has been ground and polished to save on floor finishes. A carpet had been proposed as a covering for the ground floor; this would have been replaced under UEA’s maintenance strategy every seven years. ‘When we looked at the carbon embedded in using a carpet, it was actually more than was in the raft foundation, so we got rid of the carpet and went for a ground finish,’ says Gareth Selby, an associate at architect Architype. The building’s glulam structural frame is supported by the raft. It was sourced from abroad because there are no commercial-scale glulam makers in the UK. The project does, however, make use of Corsican Pine – sourced from Thetford Forest some 30 miles away – in the construction of internal studwork walls. Timber is also used for construction of the façade brise soleil. Future climate data was generated for this project by EA’s Climate Team for an 87-year period. Using this information, Architype simulated a range of design scenarios in Passivhaus Planning Package (PHPP) to optimise the façade design. The analysis highlighted the need to rethink slightly the allocation of south-facing windows deemed essential by Passivhaus as a source of passive heating, to help limit internal gains. ‘From the analysis we boosted shading slightly by setting the windows further back into the reveals,’ explains Selby. ‘From a future perspective we developed a timber brise soleil, which can be adapted to allow more louvres to be added in the future.’

== Keeping cool ==

While the building’s lightweight construction has helped save on embodied carbon, there were some concerns that its lack of thermal mass could result in the building overheating, even in the current climate. These concerns were mitigated, in part, by floor-to-ceiling heights in excess of 3.3m on both floors which helped create sufficient volume to cope with temperature rises and ensure good daylight levels on the floorplates.

Aided by LED lighting and an intelligent control system this helped keep lighting loads to a minimum and kept the primary energy demand below 120kWh/m2/y. The building is exceptionally airtight, even by Passivhaus standards. ‘We achieved an airtightness of 0.21m3/m2 at 50Pa, which is three times better than needed for Passivhaus compliance, and about 100 times better than is required under Part L,’ laughs Bassett. A demand-led ventilation system controlled by occupancy and CO2 sensors delivers fresh air to keep occupants comfortable. The building has three ventilation plantrooms: one in each wing and one in the central auditorium. Each plantoom houses a Swegon Gold, Passivhaus certified, air handling unit (AHU) incorporating a thermal wheel. Air from AHUs is ducted to the floors and distributed via Trox VAV units mounted in a services distribution bulkhead that doubles as an attenuated return air plenum. Air is extracted from the wings via the toilet blocks (there are no toilet extract fans); extracted air is then passed through the thermal wheel before being discharged to outside. Unusually for a Passivhaus project, the Enterprise Centre does include a small amount of cooling in the 300-seat auditorium to ensure it remains comfortable in summer. This is provided by a small direct expansion system with a cooling coil positioned in the supply air stream and a heat rejection unit situated in the exhaust air steam. ‘We’re using cooling just to peak-lop the fresh air supply temperature in summer because the students will be dressed appropriately for the conditions,’ explains James Hepburn, engineer director at BDP, the project’s services engineer. In the main floor areas there is no cooling. Instead occupants can open the building’s windows to provide ventilation. The ventilation strategy, and other aspects of the scheme, were agreed with the UEA’s estates team, who were involved with the project under its Soft Landings initiative and led by Stuart Thompson, senior design manager at Morgan Sindall. This is a good thing because estates will probably need to be proactive in managing the operation of this highly value engineered ventilation solution and innovative building. Heat for the building comes from the UEA’s district heating system. The heating mains ran close to the building, which was fortunate because heat loss from the spur to the building had to be included in the Passivhaus compliance criteria. A heat interface unit incorporating two heat exchangers, one for the heating and one for the hot water – separates the building from the mains. 

One of the biggest challenges in achieving Passivhaus compliance was the provision of hot water to toilet blocks. This is because standing heat losses from hot water pipes are factored into the PHPP spreadsheet. The form of the building with its two wings meant the losses were so high that hot water in the southern wing, the one furthest from the heat interface unit, had to be provided by point-of-use local electric water heaters. Microbore pipework, which has lower standing heat losses, feeds the remaining hot water outlets. 

As far as minimising embodied carbon goes, Hepburn says: ‘We did a fair amount of research looking at different materials but we were not satisfied with the robustness of alternatives in meeting the building’s 100 year life. The best you can do is install less M&E.’ One of the constraints of Passivhaus is becoming apparent now the building is in use. One challenge of gaining certification is that small power loads are included in the Primary Energy Demand maximum. As a result, the design team spent a lot of time selecting the building’s AV systems and, to keep small power loads to a minimum, the client was keen not to flood the building with electrical sockets. ‘Passivhaus is very challenging because it limits what you can do in terms of computers and catering, which we’re finding a little bit constraining,’ remarks French. Bassett, meanwhile, has submitted his last spreadsheets for carbon emissions from deliveries and from the workforce.

The sheets include all deliveries to site, including such details as where the vehicle was from, miles driven, type of vehicle, and fuel. ‘The threshold was less than 500kg/m2 emitted CO2 over the 100-year life including construction carbon – we think we’ll be 10% below that figure,’ says Adapt’s John French. ‘From my perspective we’ve set a new standard in sustainable architecture and it has not cost the earth’.

== Window of opportunity ==

There is no cooling to the main floor areas. However, when conditions allow, the occupants can open the building’s triple-glazed windows to provide ventilation. A display panel in each room contains two LED lamps, which are illuminated when outside air temperatures are suitable to allow windows to be opened. The CO2 sensors in the room will then detect improved air quality and back off the VAV damper serving that room.

If temperatures are very hot, occupants are encouraged to leave the windows open overnight to allow night ventilation. In winter heating availability is limited and controlled by the BMS. Heat in occupied rooms is provided by ‘tiny’ radiators, each fitted with a TRV. ‘We didn’t want to run the risk of not having heating in these rooms, because the building does not have automatic windows so there is a chance a window could be left open overnight,’ explains Hepburn.

To read this article on the CIBSE website, please click [http://www.cibse.org/knowledge/building-services-case-studies here].

University of East Anglia Enterprise Centre

2015-09-01T16:09:07Z

CIBSE:

Article from the September 2015 edition of the [http://www.cibsejournal.com CIBSE Journal] by Andy Pearson. 

In aiming for Passivhaus the project team at the Enterprise Centre worked to the tightest of parameters leading to the use of 70% bio-based materials, a superairtight envelope and minimal plug loads. Is this the UK’s greenest commercial building? The Enterprise Centre at the University of East Anglia (UEA) in Norwich is targeting BREEAM Outstanding and Passivhaus certification. Designed to last for 100 years, it has been built on a brownfield site using 70% bio-based materials, many of which have been sourced locally. And it exceeds local planning requirements for 10% of the building’s energy to be from renewables, with a 480m2 roof-mounted photovoltaic array, predicted to generate 44MWh a year. 

Consequently, over its lifetime the building’s embodied carbon is predicted to be one quarter that of a conventionally constructed building. This pioneering two-storey 3,400m2 building is the new home for the Adapt Low Carbon Group, which was created to commercialise graduate start-up firms that have grown out of UEA’s world-class environmental sciences. Adapt wanted its new facilities to be an exemplar of sustainability. ‘There is no point in being a lead institution on climate change if we don’t act on our values and build a site that can help mitigate climate change and can cope with its impacts,’ says group CEO John French. The biggest clue to the £11.6m building’s climate mitigation aspirations is its cladding – the building is wrapped in thatch. In a dramatic reinterpretation of the use of this traditional Norfolk roofing material, the thatch is formed of 250mm thick layers of straw set in prefabricated, vertically-hung timber cassettes – a world first according to Morgan Sindall’s senior site manager Ken Bassett. The thatch holds the carbon absorbed by plants photosynthesising for 100 years or so. ‘We recognised thatch would be a good carbon negative local material,’ Bassett explains. The unique cassette system was developed under a single point delivery contract by Morgan Sindall and project architect Architype. The cassettes were thatched horizontally by local thatchers, who were able to carry out the work safely in barns through the winter when traditionally there is very little work for them. ‘Once all the panels were in place, a thatcher came along and dressed the wall with a machine like a large hedge cutter to give the building a haircut,’ says Bassett. The use of cassettes has enabled this traditional material to be installed in much the same way as conventional cladding panels. Significantly, the panels sit outside of the building’s airtightness and insulation line and are not part of the structure. Thatch cladding features on every elevation of this E-shaped building. The building’s form was the result of the need to maximise the amount of daylight. The top and bottom elements of the E are formed by the two main wings, one of which is for teaching, and the other for start-ups. The building is orientated such that the wing façades face north and south. A predominantly transparent block links the wings, in its centre, and forming the middle of the E is a 300-seat auditorium. 

== Achieving CO2 targets ==

The amount of carbon embodied in the building’s thatch cladding cassettes was calculated by Architype using its newly developed Rapiere software, using information taken from the project BIM model. The client set the design team a target of 500kg of emitted CO2 per square metre over the 100-year life of the building. This meant that every material was selected based on an assessment of embodied carbon and cost. ‘Normally I’d look at cost and programme when selecting materials but here it was a complex equation. We had to look holistically to ensure we reached the optimum balance between achieving BREEAM and Passivhaus targets, minimised embodied energy and lifecycle costs while ensuring we met the construction programme,’ explains Bassett. The building’s foundations were one area where the team had to work extremely hard to find an appropriate solution. The building is supported on a glulam timber frame. Originally it was proposed the frame would be supported on small concrete pad foundations and that the building would feature a timber ground floor supported from the glulam columns. However, Morgan Sindall’s geotechnical investigation revealed a site dotted with sinkholes and the remnants of a glacial riverbed. This resulted in the pad proposal being abandoned, along with the timber ground floor, in favour of a 375mm thick concrete raft foundation incorporating three layers of 98% recycled steel reinforcement.

== Not just a cement mix ==

Concrete has a high level of embodied carbon as a result of the use of cement produced by heating Portland stone to about 1,400°C. ‘Using 1,000m3 of ordinary concrete for the raft would have knocked the project way off its carbon target,’ Bassett explains. Morgan Sindall worked in partnership with its concrete supplier to produce a mix incorporating ground granulated blast furnace slag, which allowed 70% of the cement to be removed from the mix. In addition, recycled sand and responsibly sourced aggregate were also used. ‘This concrete had 38% embodied carbon when compared to ordinary concrete of a comparable mix,’ proclaims Bassett. The raft was cast on a base of Isoquick polystyrene insulation, positioned on a subbase formed from crushed, recycled basement salvaged from the demolition of a nearby hospital. For this project the manufacturer developed special polystyrene kerb units which not only removed the need for shuttering but, equally importantly, enabled the insulating envelope to continue from under the concrete raft to join up with the insulation in the wall minimising heat losses.

‘The solution worked brilliantly,’ says Bassett. In keeping with the low-carbon philosophy, the raft’s top surface has been ground and polished to save on floor finishes. A carpet had been proposed as a covering for the ground floor; this would have been replaced under UEA’s maintenance strategy every seven years. ‘When we looked at the carbon embedded in using a carpet, it was actually more than was in the raft foundation, so we got rid of the carpet and went for a ground finish,’ says Gareth Selby, an associate at architect Architype. The building’s glulam structural frame is supported by the raft. It was sourced from abroad because there are no commercial-scale glulam makers in the UK. The project does, however, make use of Corsican Pine – sourced from Thetford Forest some 30 miles away – in the construction of internal studwork walls. Timber is also used for construction of the façade brise soleil. Future climate data was generated for this project by EA’s Climate Team for an 87-year period. Using this information, Architype simulated a range of design scenarios in Passivhaus Planning Package (PHPP) to optimise the façade design. The analysis highlighted the need to rethink slightly the allocation of south-facing windows deemed essential by Passivhaus as a source of passive heating, to help limit internal gains. ‘From the analysis we boosted shading slightly by setting the windows further back into the reveals,’ explains Selby. ‘From a future perspective we developed a timber brise soleil, which can be adapted to allow more louvres to be added in the future.’

== Keeping cool ==

While the building’s lightweight construction has helped save on embodied carbon, there were some concerns that its lack of thermal mass could result in the building overheating, even in the current climate. These concerns were mitigated, in part, by floor-to-ceiling heights in excess of 3.3m on both floors which helped create sufficient volume to cope with temperature rises and ensure good daylight levels on the floorplates.

Aided by LED lighting and an intelligent control system this helped keep lighting loads to a minimum and kept the primary energy demand below 120kWh/m2/y. The building is exceptionally airtight, even by Passivhaus standards. ‘We achieved an airtightness of 0.21m3/m2 at 50Pa, which is three times better than needed for Passivhaus compliance, and about 100 times better than is required under Part L,’ laughs Bassett. A demand-led ventilation system controlled by occupancy and CO2 sensors delivers fresh air to keep occupants comfortable. The building has three ventilation plantrooms: one in each wing and one in the central auditorium. Each plantoom houses a Swegon Gold, Passivhaus certified, air handling unit (AHU) incorporating a thermal wheel. Air from AHUs is ducted to the floors and distributed via Trox VAV units mounted in a services distribution bulkhead that doubles as an attenuated return air plenum. Air is extracted from the wings via the toilet blocks (there are no toilet extract fans); extracted air is then passed through the thermal wheel before being discharged to outside. Unusually for a Passivhaus project, the Enterprise Centre does include a small amount of cooling in the 300-seat auditorium to ensure it remains comfortable in summer. This is provided by a small direct expansion system with a cooling coil positioned in the supply air stream and a heat rejection unit situated in the exhaust air steam. ‘We’re using cooling just to peak-lop the fresh air supply temperature in summer because the students will be dressed appropriately for the conditions,’ explains James Hepburn, engineer director at BDP, the project’s services engineer. In the main floor areas there is no cooling. Instead occupants can open the building’s windows to provide ventilation. The ventilation strategy, and other aspects of the scheme, were agreed with the UEA’s estates team, who were involved with the project under its Soft Landings initiative and led by Stuart Thompson, senior design manager at Morgan Sindall. This is a good thing because estates will probably need to be proactive in managing the operation of this highly value engineered ventilation solution and innovative building. Heat for the building comes from the UEA’s district heating system. The heating mains ran close to the building, which was fortunate because heat loss from the spur to the building had to be included in the Passivhaus compliance criteria. A heat interface unit incorporating two heat exchangers, one for the heating and one for the hot water – separates the building from the mains. 

One of the biggest challenges in achieving Passivhaus compliance was the provision of hot water to toilet blocks. This is because standing heat losses from hot water pipes are factored into the PHPP spreadsheet. The form of the building with its two wings meant the losses were so high that hot water in the southern wing, the one furthest from the heat interface unit, had to be provided by point-of-use local electric water heaters. Microbore pipework, which has lower standing heat losses, feeds the remaining hot water outlets. 

As far as minimising embodied carbon goes, Hepburn says: ‘We did a fair amount of research looking at different materials but we were not satisfied with the robustness of alternatives in meeting the building’s 100 year life. The best you can do is install less M&E.’ One of the constraints of Passivhaus is becoming apparent now the building is in use. One challenge of gaining certification is that small power loads are included in the Primary Energy Demand maximum. As a result, the design team spent a lot of time selecting the building’s AV systems and, to keep small power loads to a minimum, the client was keen not to flood the building with electrical sockets. ‘Passivhaus is very challenging because it limits what you can do in terms of computers and catering, which we’re finding a little bit constraining,’ remarks French. Bassett, meanwhile, has submitted his last spreadsheets for carbon emissions from deliveries and from the workforce.

The sheets include all deliveries to site, including such details as where the vehicle was from, miles driven, type of vehicle, and fuel. ‘The threshold was less than 500kg/m2 emitted CO2 over the 100-year life including construction carbon – we think we’ll be 10% below that figure,’ says Adapt’s John French. ‘From my perspective we’ve set a new standard in sustainable architecture and it has not cost the earth’.

== Window of opportunity ==

There is no cooling to the main floor areas. However, when conditions allow, the occupants can open the building’s triple-glazed windows to provide ventilation. A display panel in each room contains two LED lamps, which are illuminated when outside air temperatures are suitable to allow windows to be opened. The CO2 sensors in the room will then detect improved air quality and back off the VAV damper serving that room.

If temperatures are very hot, occupants are encouraged to leave the windows open overnight to allow night ventilation. In winter heating availability is limited and controlled by the BMS. Heat in occupied rooms is provided by ‘tiny’ radiators, each fitted with a TRV. ‘We didn’t want to run the risk of not having heating in these rooms, because the building does not have automatic windows so there is a chance a window could be left open overnight,’ explains Hepburn.

To read this article on the CIBSE website, please click [http://www.cibse.org/knowledge/building-services-case-studies here].

University of East Anglia Enterprise Centre

2015-09-01T15:54:46Z

CIBSE: Created page with " Article from the September 2015 edition of the [http://www.cibsejournal.com CIBSE Journal] by Andy Pearson. In aiming for Passivhaus the project team at the Enterprise Ce..."

Article from the September 2015 edition of the [http://www.cibsejournal.com CIBSE Journal] by Andy Pearson. 

In aiming for Passivhaus the project team at the Enterprise Centre worked to the tightest of parameters leading to the use of 70% bio-based materials, a superairtight envelope and minimal plug loads. Is this the UK’s greenest commercial building? The Enterprise Centre at the University of East Anglia (UEA) in Norwich is targeting BREEAM Outstanding and Passivhaus certification. Designed to last for 100 years, it has been built on a brownfield site using 70% bio-based materials, many of which have been sourced locally. And it exceeds local planning requirements for 10% of the building’s energy to be from renewables, with a 480m2 roof-mounted photovoltaic array, predicted to generate 44MWh a year. 

Consequently, over its lifetime the building’s embodied carbon is predicted to be one quarter that of a conventionally constructed building. This pioneering two-storey 3,400m2 building is the new home for the Adapt Low Carbon Group, which was created to commercialise graduate start-up firms that have grown out of UEA’s world-class environmental sciences. Adapt wanted its new facilities to be an exemplar of sustainability. ‘There is no point in being a lead institution on climate change if we don’t act on our values and build a site that can help mitigate climate change and can cope with its impacts,’ says group CEO John French. The biggest clue to the £11.6m building’s climate mitigation aspirations is its cladding – the building is wrapped in thatch. In a dramatic reinterpretation of the use of this traditional Norfolk roofing material, the thatch is formed of 250mm thick layers of straw set in prefabricated, vertically-hung timber cassettes – a world first according to Morgan Sindall’s senior site manager Ken Bassett. The thatch holds the carbon absorbed by plants photosynthesising for 100 years or so. ‘We recognised thatch would be a good carbon negative local material,’ Bassett explains. The unique cassette system was developed under a single point delivery contract by Morgan Sindall and project architect Architype. The cassettes were thatched horizontally by local thatchers, who were able to carry out the work safely in barns through the winter when traditionally there is very little work for them. ‘Once all the panels were in place, a thatcher came along and dressed the wall with a machine like a large hedge cutter to give the building a haircut,’ says Bassett. The use of cassettes has enabled this traditional material to be installed in much the same way as conventional cladding panels. Significantly, the panels sit outside of the building’s airtightness and insulation line and are not part of the structure. Thatch cladding features on every elevation of this E-shaped building. The building’s form was the result of the need to maximise the amount of daylight. The top and bottom elements of the E are formed by the two main wings, one of which is for teaching, and the other for start-ups. The building is orientated such that the wing façades face north and south. A predominantly transparent block links the wings, in its centre, and forming the middle of the E is a 300-seat auditorium. 

== Achieving CO2 targets ==

The amount of carbon embodied in the building’s thatch cladding cassettes was calculated by Architype using its newly developed Rapiere software, using information taken from the project BIM model. The client set the design team a target of 500kg of emitted CO2 per square metre over the 100-year life of the building. This meant that every material was selected based on an assessment of embodied carbon and cost. ‘Normally I’d look at cost and programme when selecting materials but here it was a complex equation. We had to look holistically to ensure we reached the optimum balance between achieving BREEAM and Passivhaus targets, minimised embodied energy and lifecycle costs while ensuring we met the construction programme,’ explains Bassett. The building’s foundations were one area where the team had to work extremely hard to find an appropriate solution. The building is supported on a glulam timber frame. Originally it was proposed the frame would be supported on small concrete pad foundations and that the building would feature a timber ground floor supported from the glulam columns. However, Morgan Sindall’s geotechnical investigation revealed a site dotted with sinkholes and the remnants of a glacial riverbed. This resulted in the pad proposal being abandoned, along with the timber ground floor, in favour of a 375mm thick concrete raft foundation incorporating three layers of 98% recycled steel reinforcement.

== Not just a cement mix ==

Concrete has a high level of embodied carbon as a result of the use of cement produced by heating Portland stone to about 1,400°C. ‘Using 1,000m3 of ordinary concrete for the raft would have knocked the project way off its carbon target,’ Bassett explains. Morgan Sindall worked in partnership with its concrete supplier to produce a mix incorporating ground granulated blast furnace slag, which allowed 70% of the cement to be removed from the mix. In addition, recycled sand and responsibly sourced aggregate were also used. ‘This concrete had 38% embodied carbon when compared to ordinary concrete of a comparable mix,’ proclaims Bassett. The raft was cast on a base of Isoquick polystyrene insulation, positioned on a subbase formed from crushed, recycled basement salvaged from the demolition of a nearby hospital. For this project the manufacturer developed special polystyrene kerb units which not only removed the need for shuttering but, equally importantly, enabled the insulating envelope to continue from under the concrete raft to join up with the insulation in the wall minimising heat losses.

‘The solution worked brilliantly,’ says Bassett. In keeping with the low-carbon philosophy, the raft’s top surface has been ground and polished to save on floor finishes. A carpet had been proposed as a covering for the ground floor; this would have been replaced under UEA’s maintenance strategy every seven years. ‘When we looked at the carbon embedded in using a carpet, it was actually more than was in the raft foundation, so we got rid of the carpet and went for a ground finish,’ says Gareth Selby, an associate at architect Architype. The building’s glulam structural frame is supported by the raft. It was sourced from abroad because there are no commercial-scale glulam makers in the UK. The project does, however, make use of Corsican Pine – sourced from Thetford Forest some 30 miles away – in the construction of internal studwork walls. Timber is also used for construction of the façade brise soleil. Future climate data was generated for this project by EA’s Climate Team for an 87-year period. Using this information, Architype simulated a range of design scenarios in Passivhaus Planning Package (PHPP) to optimise the façade design. The analysis highlighted the need to rethink slightly the allocation of south-facing windows deemed essential by Passivhaus as a source of passive heating, to help limit internal gains. ‘From the analysis we boosted shading slightly by setting the windows further back into the reveals,’ explains Selby. ‘From a future perspective we developed a timber brise soleil, which can be adapted to allow more louvres to be added in the future.’

== Keeping cool ==

While the building’s lightweight construction has helped save on embodied carbon, there were some concerns that its lack of thermal mass could result in the building overheating, even in the current climate. These concerns were mitigated, in part, by floor-to-ceiling heights in excess of 3.3m on both floors which helped create sufficient volume to cope with temperature rises and ensure good daylight levels on the floorplates.

Aided by LED lighting and an intelligent control system this helped keep lighting loads to a minimum and kept the primary energy demand below 120kWh/m2/y. The building is exceptionally airtight, even by Passivhaus standards. ‘We achieved an airtightness of 0.21m3/m2 at 50Pa, which is three times better than needed for Passivhaus compliance, and about 100 times better than is required under Part L,’ laughs Bassett. A demand-led ventilation system controlled by occupancy and CO2 sensors delivers fresh air to keep occupants comfortable. The building has three ventilation plantrooms: one in each wing and one in the central auditorium. Each plantoom houses a Swegon Gold, Passivhaus certified, air handling unit (AHU) incorporating a thermal wheel. Air from AHUs is ducted to the floors and distributed via Trox VAV units mounted in a services distribution bulkhead that doubles as an attenuated return air plenum. Air is extracted from the wings via the toilet blocks (there are no toilet extract fans); extracted air is then passed through the thermal wheel before being discharged to outside. Unusually for a Passivhaus project, the Enterprise Centre does include a small amount of cooling in the 300-seat auditorium to ensure it remains comfortable in summer. This is provided by a small direct expansion system with a cooling coil positioned in the supply air stream and a heat rejection unit situated in the exhaust air steam. ‘We’re using cooling just to peak-lop the fresh air supply temperature in summer because the students will be dressed appropriately for the conditions,’ explains James Hepburn, engineer director at BDP, the project’s services engineer. In the main floor areas there is no cooling. Instead occupants can open the building’s windows to provide ventilation. The ventilation strategy, and other aspects of the scheme, were agreed with the UEA’s estates team, who were involved with the project under its Soft Landings initiative and led by Stuart Thompson, senior design manager at Morgan Sindall. This is a good thing because estates will probably need to be proactive in managing the operation of this highly value engineered ventilation solution and innovative building. Heat for the building comes from the UEA’s district heating system. The heating mains ran close to the building, which was fortunate because heat loss from the spur to the building had to be included in the Passivhaus compliance criteria. A heat interface unit incorporating two heat exchangers, one for the heating and one for the hot water – separates the building from the mains. 

One of the biggest challenges in achieving Passivhaus compliance was the provision of hot water to toilet blocks. This is because standing heat losses from hot water pipes are factored into the PHPP spreadsheet. The form of the building with its two wings meant the losses were so high that hot water in the southern wing, the one furthest from the heat interface unit, had to be provided by point-of-use local electric water heaters. Microbore pipework, which has lower standing heat losses, feeds the remaining hot water outlets. 

As far as minimising embodied carbon goes, Hepburn says: ‘We did a fair amount of research looking at different materials but we were not satisfied with the robustness of alternatives in meeting the building’s 100 year life. The best you can do is install less M&E.’ One of the constraints of Passivhaus is becoming apparent now the building is in use. One challenge of gaining certification is that small power loads are included in the Primary Energy Demand maximum. As a result, the design team spent a lot of time selecting the building’s AV systems and, to keep small power loads to a minimum, the client was keen not to flood the building with electrical sockets. ‘Passivhaus is very challenging because it limits what you can do in terms of computers and catering, which we’re finding a little bit constraining,’ remarks French. Bassett, meanwhile, has submitted his last spreadsheets for carbon emissions from deliveries and from the workforce.

The sheets include all deliveries to site, including such details as where the vehicle was from, miles driven, type of vehicle, and fuel. ‘The threshold was less than 500kg/m2 emitted CO2 over the 100-year life including construction carbon – we think we’ll be 10% below that figure,’ says Adapt’s John French. ‘From my perspective we’ve set a new standard in sustainable architecture and it has not cost the earth’.

== Window of opportunity ==

There is no cooling to the main floor areas. However, when conditions allow, the occupants can open the building’s triple-glazed windows to provide ventilation. A display panel in each room contains two LED lamps, which are illuminated when outside air temperatures are suitable to allow windows to be opened. The CO2 sensors in the room will then detect improved air quality and back off the VAV damper serving that room.

If temperatures are very hot, occupants are encouraged to leave the windows open overnight to allow night ventilation. In winter heating availability is limited and controlled by the BMS. Heat in occupied rooms is provided by ‘tiny’ radiators, each fitted with a TRV. ‘We didn’t want to run the risk of not having heating in these rooms, because the building does not have automatic windows so there is a chance a window could be left open overnight,’ explains Hepburn.

Predicting the energy use of the Cambridge base for the East Anglian Air Ambulance

2015-08-04T15:06:06Z

CIBSE:

Article from the August 2015 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Peter Rankin. 

Portakabin is using CIBSE’s TM54 tool to help predict energy use at a new Cambridge base for the East Anglian Air Ambulance. The article explains why the modular builder is taking an ‘honest approach’ to energy efficiency. Forecast building energy performance is important for any project, but particularly so for the East Anglian Air Ambulance (EAAA) , because every pound spent on energy means less money available to keep its helicopters in the air. The annual cost of running the vital service – which relies on charitable donations – is approximately £8.6m . Higherthan- predicted energy costs would mean channelling funding away from the operation of the air ambulance. EAAA is currently building a new twostorey operations base for mission control and air ambulance crew at Cambridge International Airport . It is using CIBSE’s forecasting tool , TM54 Evaluating Operational Energy Performance of Buildings at the Design Stage, to give a reliable and verifi able forecast of in-use energy, and to demonstrate the energy effi ciency of the construction method The new building will come under particular scrutiny because EAAA’s newest pilot just happens to be second in line to the British throne. Prince William started flying one of the volunteer organisation’s two helicopters last month, after training for the role earlier in the year. 

== Building brief ==

EAAA’s brief for its new building included an office, mission control, mess and sleeping accommodation. The operations base was needed quickly and there was a desire to minimise disruption on the air ambulance’s airport site, so the client opted for off-site construction . Walls, roofs and floors were assembled in a factory , which mean t the superstructure could be fabricated and constructed at the same time as the groundworks. Yorkon’s off-site solution uses prefabricated modules, which are then assembled on site to create the completed building. The first stage of energy modelling is to establish occupancy patterns. The National Calculation Methodology (NCM) profi les used for Part L and EPCs were not too far off what is expected for the building; this is unusual, because the NCM tends to underestimate ‘out of hours’ use.1 

U-values of the building system are slightly better than the Part L notional building. One common problem with U-value calculations is the use of linear heat-loss calculations, which can be unrealistically optimistic, as they do not take account of repeat or intermediate thermal bridging. Fabric modelling for the project takes full account of thermal bridging, using 3D heat-flow modelling. These calculations are also backed by third-party verification to the relevant British Standards. In temperature-critical areas of the building, reversible DX heat pumps areused. In other areas an air-to-LTHW heat pump system is specifi ed; this also delivers hot water for showers and washbasins. Using the right efficiency figures in the model for heating and cooling systems is important. The availability of seasonal coefficient of performance (COP) figures has, in theory, been a great step in narrowing the gap between design and performance.

No longer can designers optimise their equipment for a single test condition. However, we must still treat seasonal COPs and energy efficiency ratios with caution, because the demand profi le used for seasonal calculations will probably not match the reality, and may not take the defrost cycle into account. Another area in which we need to be careful about how we use manufacturers’ data is ventilation, which is delivered by decentralised heat-recovery air handling units. The manufacturer claims a 70% heat-recovery efficiency for the plate heat exchangers. Heat exchanger efficiencies are determined using set conditions2 for temperature, humidity, and airfl ow, all of which will vary in reality. At this stage, a more conservative 55% fi gure3 has been used in the energy model. Lighting is LED throughout, with absence control to occupied areas, and presence control elsewhere. Daylight in the building is limited because glazing areas are designed to reduce noise nuisance from the airport outside. Nevertheless, modelling showed daylight to be benefi cial in certain areas. Controls are often cited as a key reason for buildings not performing as designed.4 The studied building has a very simple system, with a central controller for the LTHW heating system, and local controls for direct expansion (DX) systems. Cooling systems are to be coupled with ventilation to make the best use of free cooling, and systems are specified so that simultaneous heating and cooling of the same space cannot occur. Despite the best intentions of design, we must still account for the possibility that controls may not be used optimally. Giving building users control over heating and cooling systems can have its benefits, but can also increase energy consumption as users wrestle with controls – for example, setting cooling to 16°C on the misapprehension that this will cool the room more quickly.

Small-power and catering energy use were taken from estimates of equipment power draw and its use. The TM54 document offers useful guidance and examples for how to estimate small power. Small power use in the building includes computers, server, and on-board specialist medical equipment, which the flight crew will recharge in the building. TM54 encourages the use of scenarios to present a range of forecast outcomes. At this early project stage, a ‘standard practice’ forecast was created alongside a high-usage forecast. The scenarios assume that occupancy patterns are as expected, all equipment is well commissioned, maintained effectively and used appropriately, and that energy is monitored and targeted by building management. These scenarios are then given an uncertainty range to account for building management factors. More scenarios may be added at a later date – for instance, if we find that crews are carrying out more night missions than anticipated, or that crews are using the residential facilities more than expected.

== TM54 forecast ==

Figure 3 shows the TM54 forecasts for the EAAA building against the EPC modelling results and the CIBSE Guide F benchmarks. The forecast energy use is between 77.1MWh and 66.7MWh per year for the high- and standard-usage scenarios respectively, which suggests the EPC has underestimated by 46-69%. This underestimate is largely from the unregulated loads of small power and catering. 

The model forecast that lighting would be the highest single source of energy use because of the building’s long occupancy hours, particularly at night. The EPC model assumes lighting is on for 24 hours a day; this is similar to the profiles assumed for the TM54 forecast, but these may be revised for later scenarios. Choosing LEDs for efficiency and longevity has been validated by these results. This is one area in which different occupancy scenarios will have a big effect. Results suggest that the EPC model underestimated energy use for heating and cooling, because of restrictions in the EPC process when accounting for control inefficiencies, defrost cycles and in-use efficiency. Energy used for domestic hot water appears to have been overestimated in the EPC because of demand profiles assuming a far greater use of changing and shower facilities than predicted. 

 There was some difficulty in finding appropriate benchmarks in CIBSE Guide F; the closest approximations for each energy use were mostly office buildings. It is nevertheless interesting that cooling and ventilation energy use are so much higher than the modelled results. Heating and DHW energy benchmarks should be taken with the knowledge that the Guide F standards are for fossil-fuel systems rather than heat pumps.

== The advantages of TM54 ==

It is natural for design teams to be optimistic about energy efficiency, but – when it comes to energy forecasting – we must replace this with an honest approach that recognises uncertainty in data and accounts for the influence of the end user. Ultimately, operational energy use is the figure that matters to building users. Good energy modelling allows us to make effective design decisions, and enables occupants to benchmark their energy use. For the air ambulance project, going through the TM54 framework gives added confidence in design-energy modelling, and will allow the client to make informed decisions as the design progresses. The real test for the Cambridge operations base will be how the energy forecasts compare to the measured consumption. The building is due for completion in late autumn 2015.

== TM54 vs EPCs ==

CIBSE’s TM54: Evaluating Operational Energy Performance of Buildings at Design Stage sets out a framework in which to build models to forecast in-use energy. In most cases, this will involve modification of the Part L/EPC model using the same dynamic simulation software. The energy ‘performance gap’ – the difference between as-designed and as-built energy use – is a hot topic among building professionals. Data from CarbonBuzz suggest that a typical office building will consume 59% more energy than its design target.5 The Green Construction Board suggests the performance gap could be closer to 200%.6 Much of the discussion has focused on commissioning, build quality and the influence of the end user. These are crucial to energy performance in operation, but one factor that is often misunderstood is energy modelling. Energy Performance Certificates (EPCs) are not designed to predict in-use energy performance. EPC and Part L modelling is designed, instead, to assess the theoretical energy and CO2 efficiency of a building in a method common to all buildings of its type. To make different buildings comparable, the EPC method must ignore actual operational profiles and variables such as small-power loads. Some fixed building services – such as lifts, escalators, security systems, and emergency lighting – are also ignored. This rigidity means assessors cannot use their judgement to make realistic and conservative adjustments to standard inputs, or to allow for how occupants will use the building. A lack of reliable energy data at design stage not only means disappointment at the as-built stage, but also hampers our ability to make well-informed design decisions. Percentage CO2 savings targets from renewables are a good example of where as-measured results may be well below design targets.

== References: ==

1 Technology Strategy Board – The performance gap in non-domestic buildings (2013). 2 BS EN 308:1997 Heat exchangers. Test procedures for establishing the performance of air to air and flue gases heat-recovery devices. 3 ECA Energy Technology Criteria List 2013 – Air to Air Energy Recovery. 4 Innovate UK – Building Performance Evaluation Programme Early Findings from Non-Domestic Projects (2014). 5 From summary of audits performed on CarbonBuzz by the UCL Energy Institute. 6 Green Construction Board – The Performance Gap: Causes & Solutions (2013).

For the full article on the [http://www.designingbuildings.co.uk/wiki/User:CIBSE CIBSE] website click [http://www.cibsejournal.com here].

Predicting the energy use of the Cambridge base for the East Anglian Air Ambulance

2015-08-04T15:05:09Z

CIBSE: Created page with " Article from the August 2015 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Peter Rankin. Portakabin is using CIBSE’s TM54 tool to help predict ..."

Article from the August 2015 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Peter Rankin. 

Portakabin is using CIBSE’s TM54 tool to help predict energy use at a new Cambridge base for the East Anglian Air Ambulance. The article explains why the modular builder is taking an ‘honest approach’ to energy efficiency. Forecast building energy performance is important for any project, but particularly so for the East Anglian Air Ambulance (EAAA) , because every pound spent on energy means less money available to keep its helicopters in the air. The annual cost of running the vital service – which relies on charitable donations – is approximately £8.6m . Higherthan- predicted energy costs would mean channelling funding away from the operation of the air ambulance. EAAA is currently building a new twostorey operations base for mission control and air ambulance crew at Cambridge International Airport . It is using CIBSE’s forecasting tool , TM54 Evaluating Operational Energy Performance of Buildings at the Design Stage, to give a reliable and verifi able forecast of in-use energy, and to demonstrate the energy effi ciency of the construction method The new building will come under particular scrutiny because EAAA’s newest pilot just happens to be second in line to the British throne. Prince William started flying one of the volunteer organisation’s two helicopters last month, after training for the role earlier in the year. 

== Building brief ==

EAAA’s brief for its new building included an office, mission control, mess and sleeping accommodation. The operations base was needed quickly and there was a desire to minimise disruption on the air ambulance’s airport site, so the client opted for off-site construction . Walls, roofs and floors were assembled in a factory , which mean t the superstructure could be fabricated and constructed at the same time as the groundworks. Yorkon’s off-site solution uses prefabricated modules, which are then assembled on site to create the completed building. The first stage of energy modelling is to establish occupancy patterns. The National Calculation Methodology (NCM) profi les used for Part L and EPCs were not too far off what is expected for the building; this is unusual, because the NCM tends to underestimate ‘out of hours’ use.1 

U-values of the building system are slightly better than the Part L notional building. One common problem with U-value calculations is the use of linear heat-loss calculations, which can be unrealistically optimistic, as they do not take account of repeat or intermediate thermal bridging. Fabric modelling for the project takes full account of thermal bridging, using 3D heat-flow modelling. These calculations are also backed by third-party verification to the relevant British Standards. In temperature-critical areas of the building, reversible DX heat pumps areused. In other areas an air-to-LTHW heat pump system is specifi ed; this also delivers hot water for showers and washbasins. Using the right

efficiency fi gures in the model for heating and cooling systems is
important. The availability of seasonal coefficient of performance (COP) figures has, in theory, been a great step in narrowing the gap between design and performance.

No longer can designers optimise their equipment for a single test condition. However, we must still treat seasonal COPs and energy efficiency ratios with caution, because the demand profi le used for seasonal calculations will probably not match the reality, and may not take the defrost cycle into account. Another area in which we need to be careful about how we use manufacturers’ data is ventilation, which is delivered by decentralised heat-recovery air handling units. The manufacturer claims a 70% heat-recovery efficiency for the plate heat exchangers. Heat exchanger efficiencies are determined using set conditions2 for temperature, humidity, and airfl ow, all of which will vary in reality. At this stage, a more conservative 55% fi gure3 has been used in the energy model. Lighting is LED throughout, with absence control to occupied areas, and presence control elsewhere. Daylight in the building is limited because glazing areas are designed to reduce noise nuisance from the airport outside. Nevertheless, modelling showed daylight to be benefi cial in certain areas. Controls are often cited as a key reason for buildings not performing as designed.4 The studied building has a very simple system, with a central controller for the LTHW heating system, and local controls for direct expansion (DX) systems. Cooling systems are to be coupled with ventilation to make the best use of free cooling, and systems are specified so that simultaneous heating and cooling of the same space cannot occur. Despite the best intentions of design, we must still account for the possibility that controls may not be used optimally. Giving building users control over heating and cooling systems can have its benefits, but can also increase energy consumption as users wrestle with controls – for example, setting cooling to 16°C on the misapprehension that this will cool the room more quickly.

Small-power and catering energy use were taken from estimates of equipment power draw and its use. The TM54 document offers useful guidance and examples for how to estimate small power. Small power use in the building includes computers, server, and on-board specialist medical equipment, which the flight crew will recharge in the building. TM54 encourages the use of scenarios to present a range of forecast outcomes. At this early project stage, a ‘standard practice’ forecast was created alongside a high-usage forecast. The scenarios assume that occupancy patterns are as expected, all equipment is well commissioned, maintained effectively and used appropriately, and that energy is monitored and targeted by building management. These scenarios are then given an uncertainty range to account for building management factors. More scenarios may be added at a later date – for instance, if we find that crews are carrying out more night missions than anticipated, or
that crews are using the residential facilities more than expected.
== TM54 forecast ==

Figure 3 shows the TM54 forecasts for the EAAA building against the EPC modelling results and the CIBSE Guide F benchmarks. The forecast energy use is between 77.1MWh and 66.7MWh per year for the high- and standard-usage scenarios respectively, which suggests the EPC has underestimated by 46-69%. This underestimate is largely from the unregulated loads of small power and catering. 

The model forecast that lighting would be the highest single source of energy use because of the building’s long occupancy hours, particularly at night. The EPC model assumes lighting is on for 24 hours a day; this is similar to the profiles assumed for the TM54 forecast, but these may be revised for later scenarios. Choosing LEDs for efficiency and longevity has been validated by these results. This is one area in which different occupancy scenarios will have a big effect. Results suggest that the EPC model underestimated energy use for heating and cooling, because of restrictions in the EPC process when accounting for control inefficiencies, defrost cycles and in-use efficiency. Energy used for domestic hot water appears to have been overestimated in the EPC because of demand profiles assuming a far greater use of changing and shower facilities than predicted. 

 There was some difficulty in finding appropriate benchmarks in CIBSE Guide F; the closest approximations for each energy use were mostly office buildings. It is nevertheless interesting that cooling and ventilation energy use are so much higher than the modelled results. Heating and DHW energy benchmarks should be taken with the knowledge that the Guide F standards are for fossil-fuel
systems rather than heat pumps.
== The advantages of TM54 ==

It is natural for design teams to be optimistic about energy efficiency, but – when it comes to energy forecasting – we must replace this with an honest approach that recognises uncertainty in data and accounts for the influence of the end user. Ultimately, operational energy use is the figure that matters to building users. Good energy modelling allows us to make effective design decisions, and enables occupants to benchmark their energy use. For the air ambulance project, going through the TM54 framework gives added confidence in design-energy modelling, and will allow the client to make informed decisions as the design progresses. The real test for the Cambridge operations base will be how the energy
forecasts compare to the measured consumption. The building is due for completion in late autumn 2015.
== TM54 vs EPCs ==

CIBSE’s TM54: Evaluating Operational Energy Performance of Buildings at Design Stage sets out a framework in which to build models to forecast in-use energy. In most cases, this will involve modification of the Part L/EPC model using the same dynamic simulation software. The energy ‘performance gap’ – the difference between as-designed and as-built energy use – is a hot topic among building professionals. Data from CarbonBuzz suggest that a typical office building will consume 59% more energy than its design target.5 The Green Construction Board suggests the performance gap could be closer to 200%.6 Much of the discussion has focused on commissioning, build quality and the influence of the end user. These are crucial to energy performance in operation, but one factor that is often misunderstood is energy modelling. Energy Performance Certificates (EPCs) are not designed to predict in-use energy performance. EPC and Part L modelling is designed, instead, to assess the theoretical energy and CO2 efficiency of a building in a method common to all buildings of its type. To make different buildings comparable, the EPC method must ignore actual operational profiles and variables such as small-power loads. Some fixed building services – such as lifts, escalators, security systems, and emergency lighting – are also ignored. This rigidity means assessors cannot use their judgement to make realistic and conservative adjustments to standard inputs, or to allow for how occupants will use the building. A lack of reliable energy data at design stage not only means disappointment at the as-built stage, but also hampers our ability to make well-informed design decisions. Percentage CO2 savings targets from

renewables are a good example of where as-measured results may be well
below design targets.
== References: ==

1 Technology Strategy Board – The performance gap in non-domestic buildings (2013). 2 BS EN 308:1997 Heat exchangers. Test procedures for establishing the performance of air to air and flue gases heat-recovery devices. 3 ECA Energy Technology Criteria List 2013 – Air to Air Energy Recovery. 4 Innovate UK – Building Performance Evaluation Programme Early Findings from Non-Domestic Projects (2014). 5 From summary of audits performed on CarbonBuzz by the UCL Energy Institute. 6 Green Construction Board – The Performance Gap: Causes & Solutions (2013).

For the full article on the [http://www.designingbuildings.co.uk/wiki/User:CIBSE CIBSE] website click [http://www.cibsejournal.com here].

Empower community energy management

2015-06-09T15:53:34Z

CIBSE:

Article from the June 2015 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Matthew Rhodes and Paula Quintela. 

Local electrical power networks have the potential to slash household energy bills by half, but are being held in check by regulations on domestic energy management. A pilot project in Wiltshire is showing how modern controls, clever algorithms and more enlightened legislation could transform UK energy supply. Encraft’s Matthew Rhodes and Paula Quintela, of e2E Services, explain.

Empower is a new approach to optimising energy performance in domestic buildings. It works by managing energy demand and supply across a community or portfolio of connected buildings, rather than merely optimising energy demand and supply in individual properties. The technology is being developed and piloted by a consortium led by telecommunications software company e2E Services and energy specialists Encraft, supported by the University of Nottingham, and Bath & West Community Energy (BWCE). An initial pilot project in Wiltshire is being part-funded by Innovate UK. The theory is simple. As all energy managers know, smart building controls and management systems can often unlock significant benefits for individual buildings. However, if you can connect multiple buildings, new opportunities emerge – for example, supplying electricity or heat generated on one site directly to another,

or storing energy in one location knowing there will be demand in a neighbouring building in the near future. At the moment, most of these optimisation opportunities are lost in the UK energy market, because the system is designed from the top down and controlled centrally.

It simply cannot cope with the complexity of optimising energy performance at multibuilding – or community – level. Even greater opportunities emerge when we move beyond instantaneous optimisation of energy use to consider the potential benefits of targeted investment in energy technologies, such as battery storage, local generation and demand management. Easy access to energy data from across a community of buildings can show where investments in these technologies add most value and, hence, improve the economics and benefits. The kind of practical improvement unlocked by community energy management is illustrated in Figure 2. 

Currently, it is entirely possible that a household with a solar PV system installed can be exporting to the grid and being paid less than 5p per unit for its electricity, while – within a few metres – another household without solar is paying up to 28p per unit, in the worst cases , but typically 15p . If the two households could connect, it should be possible to do a deal that benefits all – for example, Mr Jones agrees to buy electricity from Mrs Smith at 12p per unit. Of course, this is only the simplest potential revenue stream ; if communities get organised, they could, theoretically, access national markets for demand and frequency response – switching off appliances at times of peak demand to help avoid the need to dispatch more generation, much like large industrial customers do. Customers and communities able to access the commercial energy market can also benefi t by shifting demand to times when energy is cheaper and dispatching local energy generation when prices are high.

However, there are three main reasons this kind of arrangement is not yet happening:

● The costs of the IT and controls to manage these arrangements are too high

● Regulations prevent effi cient commercial arrangements

● Householders may be sceptical about engaging with systems that take a degree of control over their energy use.

The Empower pilot project is challenging all of these obstacles. Working with the University of Nottingham, e2E Services has developed a control algorithm that takes data from cheap ‘off the shelf’ monitoring devices in homes . This data is then used to send control signals to a selected subset of devices in individual properties across the community that have ‘opted in’ to the service (Figure 3). This cuts the cost of the control solution and makes community-level optimisation economic.

The initial results of this simulation have been very encouraging. Modelling at the University of Nottingham demonstrates 18%-27% savings for a group of five houses – all with solar PV and batteries – over a week in February, using real weather and energy-price data for the period , with the range of savings depend ent on the (user-set) constraints on appliance switching. Initially, Empower is focusing on demand shifting and trading electricity within the community via a local intermediary, but there is no reason why later versions cannot include demand-and-frequency response capabilities.

Encraft is working with BWCE to develop and test business models and commercial arrangements that enable individual households to benefi t from the technology and these potential savings. There are major regulatory issues, however, because any organisation needs an electricity supply licence to bill householders for energy, and this is expensive. However, Encraft has demonstrated that, with such a licence – which also gives the community access to the commercial energy market and half-hourly electricity prices – further savings of 8-25% are possible on individual annual fuel bills.

Access to the half-hourly market and the ability to bill customers enable the management solution to establish dynamic local tariffs, which can be used to drive control algorithms and incentivise customer behaviours. The economics of the model depends on the willingness of customers to delegate control of certain devices to Empower; typically, these will be significant items such as solar PV systems, batteries, and appliances for which the time of use is not critical, such as tumble driers. Clearly, the inclination of householders to opt in is vital to the success of this kind of solution.

For this reason, the project is piloting Empower across 12 buildings (10 houses and two commercial buildings) for three months this summer. The pilot will not only demonstrate if the simulated outcomes are replicable in reality, it will also be an opportunity to get behavioural feedback and start to gauge customer reaction to this kind of approach.

There has been no difficulty in finding volunteers for the pilot, but the initial view of the project team is that local community engagement and leadership – above all trust – are vital to this kind of project and technology, which is why the support of BWCE has been so important. The major regulatory challenge will lie in reconciling this need for local trust and leadership with the costs and risks associated with acquiring an energy supply licence. Encraft has carried out extensive research into viable models for running community energy companies in the UK and has concluded that a minimum of around 25,000 customers is necessary to support the costs of obtaining and maintaining a full retail energy supply licence. It is possible, without a full licence, to manage domestic supplies collectively on a smaller scale for defined situations – for example, apartment blocks or small private wire networks – but there aren’t enough situations like these to support the costs of the development and marketing of a potential mass-market technology such as Empower.

Of course, the problem with running a community energy solution for 25,000 customers is that the levels of trust and engagement that characterise smaller communities are long gone with projects of this scale. The challenge, therefore, is to find ways of building trust across much larger numbers of customers or to bring down the cost of complying with regulations. The good news is that there are signs that the latter is beginning to happen. The government and the UK energy regulator, Ofgem, have made limited attempts to make the process cheaper – for example, they published a Community Energy Strategy in January 2014, which included the concept of a ‘licence lite’ for community-based energy companies. More practically, the continued entry of new players into the energy market is resulting in greater willingness by incumbents to innovate. Ovo and First Utility, for example, have interesting offers to communities – including ‘white label’ community energy models – and on using smart energy technology.

Meanwhile, the team behind Empower is already thinking beyond its Wiltshire pilot to a world in which community-level optimisation of energy systems is the norm. Encraft and e2E have just started a second project – also funded by Innovate UK through the Energy Catalyst scheme – to develop a sub-station-level control algorithm that will make it possible for the distribution networks to manage multiple community energy schemes across a city or sub-region. The emerging world of smart networks and smart grids is creating significant opportunities for technical and commercial innovation across the world.

MATTHEW RHODES is managing director of Encraft.

PAULA QUINTELA is project technical lead for Empower at e2E Services.

For the full article on the [http://www.designingbuildings.co.uk/wiki/CIBSE CIBSE] website click [http://www.designingbuildings.co.uk/w/index.php?title=Www.cibsejournal.com&action=edit&redlink=1 here].

Empower community energy management

2015-06-09T15:52:32Z

CIBSE:

Article from the June 2015 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Matthew Rhodes and Paula Quintela. 

Local electrical power networks have the potential to slash household energy bills by half, but are being held in check by regulations on domestic energy management. A pilot project in Wiltshire is showing how modern controls, clever algorithms and more enlightened legislation could transform UK energy supply. Encraft’s Matthew Rhodes and Paula Quintela, of e2E Services, explain.

Empower is a new approach to optimising energy performance in domestic buildings. It works by managing energy demand and supply across a community or portfolio of connected buildings, rather than merely optimising energy demand and supply in individual properties. The technology is being developed and piloted by a consortium led by telecommunications software company e2E Services and energy specialists Encraft, supported by the University of Nottingham, and Bath & West Community Energy (BWCE). An initial pilot project in Wiltshire is being part-funded by Innovate UK. The theory is simple. As all energy managers know, smart building controls and management systems can often unlock significant benefits for individual buildings. However, if you can connect multiple buildings, new opportunities emerge – for example, supplying electricity or heat generated on one site directly to another,

or storing energy in one location knowing there will be demand in a neighbouring building in the near future. At the moment, most of these optimisation opportunities are lost in the UK energy market, because the system is designed from the top down and controlled centrally.

It simply cannot cope with the complexity of optimising energy performance at multibuilding – or community – level. Even greater opportunities emerge when we move beyond instantaneous optimisation of energy use to consider the potential benefits of targeted investment in energy technologies, such as battery storage, local generation and demand management. Easy access to energy data from across a community of buildings can show where investments in these technologies add most value and, hence, improve the economics and benefits. The kind of practical improvement unlocked by community energy management is illustrated in Figure 2.

 Currently, it is entirely possible that a household with a solar PV system installed can be exporting to the grid and being paid less than 5p per unit for its electricity, while – within a few metres – another household without solar is paying up to 28p per unit, in the worst cases , but typically 15p . If the two households could connect, it should be possible to do a deal that benefits all – for example, Mr Jones agrees to buy electricity from Mrs Smith at 12p per unit. Of course, this is only the simplest potential revenue stream ; if communities get organised, they could, theoretically, access national markets for demand and frequency response – switching off appliances at times of peak demand to help avoid the need to dispatch more generation, much like large industrial customers do. Customers and communities able to access the commercial energy market can also benefi t by shifting demand to times when energy is cheaper and dispatching local energy generation when prices are high.

However, there are three main reasons this kind of arrangement is not yet happening:

● The costs of the IT and controls to manage these arrangements are too high

● Regulations prevent effi cient commercial arrangements

● Householders may be sceptical about engaging with systems that take a degree of control over their energy use.

The Empower pilot project is challenging all of these obstacles. Working with the University of Nottingham, e2E Services has developed a control algorithm that takes data from cheap ‘off the shelf’ monitoring devices in homes . This data is then used to send control signals to a selected subset of devices in individual properties across the community that have ‘opted in’ to the service (Figure 3). This cuts the cost of the control solution and makes community-level optimisation economic. 

 The initial results of this simulation have been very encouraging. Modelling at the University of Nottingham demonstrates 18%-27% savings for a group of five houses – all with solar PV and batteries – over a week in February, using real weather and energy-price data for the period , with the range of savings depend ent on the (user-set) constraints on appliance switching. Initially, Empower is focusing on demand shifting and trading electricity within the community via a local intermediary, but there is no reason why later versions cannot include demand-and-frequency response capabilities.

Encraft is working with BWCE to develop and test business models and commercial arrangements that enable individual households to benefi t from the technology and these potential savings. There are major regulatory issues, however, because any organisation needs an electricity supply licence to bill householders for energy, and this is expensive. However, Encraft has demonstrated that, with such a licence – which also gives the community access to the commercial energy market and half-hourly electricity prices – further savings of 8-25% are possible on individual annual fuel bills.

Access to the half-hourly market and the ability to bill customers enable the management solution to establish dynamic local tariffs, which can be used to drive control algorithms and incentivise customer behaviours. The economics of the model depends on the willingness of customers to delegate control of certain devices to Empower; typically, these will be significant items such as solar PV systems, batteries, and appliances for which the time of use is not critical, such as tumble driers. Clearly, the inclination of householders to opt in is vital to the success of this kind of solution.

For this reason, the project is piloting Empower across 12 buildings (10 houses and two commercial buildings) for three months this summer. The pilot will not only demonstrate if the simulated outcomes are replicable in reality, it will also be an opportunity to get behavioural feedback and start to gauge customer reaction to this kind of approach.

There has been no difficulty in finding volunteers for the pilot, but the initial view of the project team is that local community engagement and leadership – above all trust – are vital to this kind of project and technology, which is why the support of BWCE has been so important. The major regulatory challenge will lie in reconciling this need for local trust and leadership with the costs and risks associated with acquiring an energy supply licence. Encraft has carried out extensive research into viable models for running community energy companies in the UK and has concluded that a minimum of around 25,000 customers is necessary to support the costs of obtaining and maintaining a full retail energy supply licence. It is possible, without a full licence, to manage domestic supplies collectively on a smaller scale for defined situations – for example, apartment blocks or small private wire networks – but there aren’t enough situations like these to support the costs of the development and marketing of a potential mass-market technology such as Empower.

 Of course, the problem with running a community energy solution for 25,000 customers is that the levels of trust and engagement that characterise smaller communities are long gone with projects of this scale. The challenge, therefore, is to find ways of building trust across much larger numbers of customers or to bring down the cost of complying with regulations. The good news is that there are signs that the latter is beginning to happen. The government and the UK energy regulator, Ofgem, have made limited attempts to make the process cheaper – for example, they published a Community Energy Strategy in January 2014, which included the concept of a ‘licence lite’ for community-based energy companies. More practically, the continued entry of new players into the energy market is resulting in greater willingness by incumbents to innovate. Ovo and First Utility, for example, have interesting offers to communities – including ‘white label’ community energy models – and on using smart energy technology.

Meanwhile, the team behind Empower is already thinking beyond its Wiltshire pilot to a world in which community-level optimisation of energy systems is the norm. Encraft and e2E have just started a second project – also funded by Innovate UK through the Energy Catalyst scheme – to develop a sub-station-level control algorithm that will make it possible for the distribution networks to manage multiple community energy schemes across a city or sub-region. The emerging world of smart networks and smart grids is creating significant opportunities for technical and commercial innovation across the world.

MATTHEW RHODES is managing director of Encraft.

PAULA QUINTELA is project technical lead for Empower at e2E Services.

For the full article on the [http://www.designingbuildings.co.uk/wiki/CIBSE CIBSE] website click [http://www.designingbuildings.co.uk/w/index.php?title=Www.cibsejournal.com&action=edit&redlink=1 here].

Empower community energy management

2015-06-09T15:50:42Z

CIBSE:

Article from the June 2015 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Matthew Rhodes and Paula Quintela. 

Local electrical power networks have the potential to slash household energy bills by half, but are being held in check by regulations on domestic energy management. A pilot project in Wiltshire is showing how modern controls, clever algorithms and more enlightened legislation could transform UK energy supply. Encraft’s Matthew Rhodes and Paula Quintela, of e2E Services, explain.

Empower is a new approach to optimising energy performance in domestic buildings. It works by managing energy demand and supply across a community or portfolio of connected buildings, rather than merely optimising energy demand and supply in individual properties. The technology is being developed and piloted by a consortium led by telecommunications software company e2E Services and energy specialists Encraft, supported by the University of Nottingham, and Bath & West Community Energy (BWCE). An initial pilot project in Wiltshire is being part-funded by Innovate UK. The theory is simple. As all energy managers know, smart building controls and management systems can often unlock significant benefits for individual buildings. However, if you can connect multiple buildings, new opportunities emerge – for example, supplying electricity or heat generated on one site directly to another,

or storing energy in one location knowing there will be demand in a neighbouring building in the near future. At the moment, most of these optimisation opportunities are lost in the UK energy market, because the system is designed from the top down and controlled centrally.

It simply cannot cope with the complexity of optimising energy performance

at multibuilding – or community – level. Even greater opportunities emerge when we move beyond instantaneous optimisation of energy use to consider the potential benefits of targeted investment in energy technologies, such as battery storage, local generation and demand management. Easy access to energy data from across a community of buildings can show where investments in these technologies add most value and, hence, improve the economics and benefits. The kind of practical improvement unlocked by community energy management is illustrated in Figure 2.

 Currently, it is entirely possible that a household with a solar PV system installed can be exporting to the grid and being paid less than 5p per unit for its electricity, while – within a few metres – another household without solar is paying up to 28p per unit, in the worst cases , but typically 15p . If the two households could connect, it should be possible to do a deal that benefits all – for example, Mr Jones agrees to buy electricity from Mrs Smith at 12p per unit. Of course, this is only the simplest potential revenue stream ; if communities get organised, they could, theoretically, access national markets for demand and frequency response – switching off appliances at times of peak demand to help avoid the need to dispatch more generation, much like large industrial customers do. Customers and communities able to access the commercial energy market can also benefi t by shifting demand to times when energy is cheaper and dispatching local energy generation when prices are high.

However, there are three main reasons this kind of arrangement is not yet happening:

● The costs of the IT and controls to manage these arrangements are too high

● Regulations prevent effi cient commercial arrangements

● Householders may be sceptical about engaging with systems that take a degree of control over their energy use.

The Empower pilot project is challenging all of these obstacles. Working with the University of Nottingham, e2E Services has developed a control algorithm that takes data from cheap ‘off the shelf’ monitoring devices in homes . This data is then used to send control signals to a selected subset of devices in individual properties across the community that have ‘opted in’ to the service (Figure 3). This cuts the cost of the control solution and makes community-level optimisation economic. 

 The initial results of this simulation have been very encouraging. Modelling at the University of Nottingham demonstrates 18%-27% savings for a group of five houses – all with solar PV and batteries – over a week in February, using real weather and energy-price data for the period , with the range of savings depend ent on the (user-set) constraints on appliance switching. Initially, Empower is focusing on demand shifting and trading electricity within the community via a local

intermediary, but there is no reason why later versions cannot include demand-and-frequency response capabilities.

 Encraft is working with BWCE to develop and test business models and commercial arrangements that enable individual households to benefi t from the technology and these potential savings. There are major regulatory issues, however, because any organisation needs an electricity supply licence to bill householders for energy, and this is expensive. However, Encraft has demonstrated that, with such a licence – which also gives the community access to the commercial energy market and half-hourly electricity prices – further savings of 8-25% are possible on individual

annual fuel bills.

Access to the half-hourly market and the ability to bill customers enable the management solution to establish dynamic local tariffs, which can be used to drive control algorithms and incentivise customer behaviours. The economics of the model depends on the willingness of customers to delegate control of certain devices to Empower; typically, these will be significant items such as solar PV systems, batteries, and appliances for which the time of use is not critical, such as tumble driers. Clearly, the inclination of householders to opt in is vital to the success of this kind of solution.

For this reason, the project is piloting Empower across 12 buildings (10 houses and two commercial buildings) for three months this summer. The pilot will not only demonstrate if the simulated outcomes are replicable in reality, it will also be an opportunity to get behavioural feedback and start to gauge customer reaction to this kind of approach.

There has been no difficulty in finding volunteers for the pilot, but the initial view of the project team is that local community engagement and leadership – above all trust – are vital to this kind of project and technology, which is why the support of BWCE has been so important. The major regulatory challenge will lie in reconciling this need for local trust and leadership with the costs and risks associated with acquiring an energy supply licence. Encraft has carried out extensive research into viable models for running community energy companies in the UK and has concluded that a minimum of around 25,000 customers is necessary to support the costs of obtaining and maintaining a full retail energy supply licence. It is possible, without a full licence, to manage domestic supplies collectively on a smaller scale for defined situations – for example, apartment blocks or small private wire networks – but there aren’t enough situations like these to support the costs of the development and marketing of a potential mass-market technology such as Empower.

 Of course, the problem with running a community energy solution for 25,000 customers is that the levels of trust and engagement that characterise smaller communities are long gone with projects of this scale. The challenge, therefore, is to find ways of building trust across much larger numbers of customers or to bring down the cost of complying with regulations. The good news is that there are signs that the latter is beginning to happen. The government and the UK energy regulator, Ofgem, have made limited attempts to make the process cheaper – for example, they published a Community Energy Strategy in January 2014, which included the concept of a ‘licence lite’ for community-based energy companies. More practically, the continued entry of new players into the energy market is resulting in greater willingness by incumbents to innovate. Ovo and First Utility, for example, have interesting offers to communities – including ‘white label’ community energy models – and on using smart energy technology.

Meanwhile, the team behind Empower is already thinking beyond its Wiltshire pilot to a world in which community-level optimisation of energy systems is the norm. Encraft and e2E have just started a second project – also funded by Innovate UK through the Energy Catalyst scheme – to develop a sub-station-level control algorithm that will make it possible for the distribution networks to manage multiple community energy schemes across a city or sub-region. The emerging world of smart networks and smart grids is creating significant opportunities for technical and commercial innovation across the world.

MATTHEW RHODES is managing director of Encraft.

PAULA QUINTELA is project technical lead for Empower at e2E Services.

For the full article on the [http://www.designingbuildings.co.uk/wiki/CIBSE CIBSE] website click [http://www.designingbuildings.co.uk/w/index.php?title=Www.cibsejournal.com&action=edit&redlink=1 here].

Empower community energy management

2015-06-09T15:49:07Z

CIBSE: Created page with " Article from the June 2015 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Matthew Rhodes and Paula Quintela. Local electrical power networks have ..."

Article from the June 2015 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Matthew Rhodes and Paula Quintela. 

Local electrical power networks have the potential to slash household energy bills by half, but are being held in check by regulations on domestic energy management. A pilot project in Wiltshire is showing how modern controls, clever algorithms and more enlightened legislation could transform UK energy supply. Encraft’s Matthew Rhodes and Paula Quintela, of e2E Services, explain.

Empower is a new approach to optimising energy performance in domestic buildings. It works by managing energy demand and supply across a community or portfolio of connected buildings, rather than merely optimising energy demand and supply in individual properties. The technology is being developed and piloted by a consortium led by telecommunications software company e2E Services and energy specialists Encraft, supported by the University of Nottingham, and Bath & West Community Energy (BWCE). An initial pilot project in Wiltshire is being part-funded by Innovate UK. The theory is simple. As all energy managers know, smart building controls and management systems can often unlock significant benefits for individual buildings. However, if you can connect multiple buildings, new opportunities emerge – for example, supplying electricity or heat generated on one site directly to another,

or storing energy in one location knowing there will be demand in a neighbouring building in the near future. At the moment, most of these optimisation opportunities are lost in the UK energy market, because the system is designed from the top down and controlled centrally.

It simply cannot cope with the complexity of optimising energy performance
at multibuilding – or community – level. Even greater opportunities emerge when we move beyond instantaneous optimisation of energy use to consider the potential benefits of targeted investment in energy technologies, such as battery storage, local generation and demand management. Easy access to energy data from across a community of buildings can show where investments in these technologies add most value and, hence, improve the economics and benefits. The kind of practical improvement unlocked by community energy management is illustrated in Figure 2.

 Currently, it is entirely possible that a household with a solar PV system installed can be exporting to the grid and being paid less than 5p per unit for its electricity, while – within a few metres – another household without solar is paying up to 28p per unit, in the worst cases , but typically 15p . If the two households could connect, it should be possible to do a deal that benefits all – for example, Mr Jones agrees to buy electricity from Mrs Smith at 12p per unit. Of course, this is only the simplest potential revenue stream ; if communities get organised, they could, theoretically, access national markets for demand and frequency response – switching off appliances at times of peak demand to help avoid the need to dispatch more generation, much like large industrial customers do. Customers and communities able to access the commercial energy market can also benefi t by shifting demand to times when energy is cheaper and dispatching local energy generation when prices are high.

However, there are three main reasons this kind of arrangement is not yet happening:

● The costs of the IT and controls to manage these arrangements are too high

● Regulations prevent effi cient commercial arrangements

● Householders may be sceptical about engaging with systems that take a degree of control over their energy use.

The Empower pilot project is challenging all of these obstacles. Working with the University of Nottingham, e2E Services has developed a control algorithm that takes data from cheap ‘off the shelf’ monitoring devices in homes . This data is then used to send control signals to a selected subset of devices in individual properties across the community that have ‘opted in’ to the service (Figure 3). This cuts the cost of the control solution and makes community-level optimisation economic. 

 The initial results of this simulation have been very encouraging. Modelling at the University of Nottingham demonstrates 18%-27% savings for a group of five houses – all with solar PV and batteries – over a week in February, using real weather and energy-price data for the period , with the range of savings depend ent on the (user-set) constraints on appliance switching. Initially, Empower is focusing on demand shifting and trading electricity within the community via a local

intermediary, but there is no reason why later versions cannot include demand-and-frequency response capabilities.

 Encraft is working with BWCE to develop and test business models and commercial arrangements that enable individual households to benefi t from the technology and these potential savings. There are major regulatory issues, however, because any organisation needs an electricity supply licence to bill householders for energy, and this is expensive. However, Encraft has demonstrated that, with such a licence – which also gives the community access to the commercial energy market and half-hourly electricity prices – further savings of 8-25% are possible on individual

annual fuel bills.

Access to the half-hourly market and the ability to bill customers enable the management solution to establish dynamic local tariffs, which can be used to drive control algorithms and incentivise customer behaviours. The economics of the model depends on the willingness of customers to delegate control of certain devices to Empower; typically, these will be significant items such as solar PV systems, batteries, and appliances for which the time of use is not critical, such as tumble driers. Clearly, the inclination of householders to opt in is vital to the success of this kind of solution.

For this reason, the project is piloting Empower across 12 buildings (10 houses and two commercial buildings) for three months this summer. The pilot will not only demonstrate if the simulated outcomes are replicable in reality, it will also be an opportunity to get behavioural feedback and start to gauge customer reaction to this kind of approach.

There has been no difficulty in finding volunteers for the pilot, but the initial view of the project team is that local community engagement and leadership – above all trust – are vital to this kind of project and technology, which is why the support of BWCE has been so important. The major regulatory challenge will lie in reconciling this need for local trust and leadership with the costs and risks associated with acquiring an energy supply licence. Encraft has carried out extensive research into viable models for running community energy companies in the UK and has concluded that a minimum of around 25,000 customers is necessary to support the costs of obtaining and maintaining a full retail energy supply licence. It is possible, without a full licence, to manage domestic supplies collectively on a smaller scale for defined situations – for example, apartment blocks or small private wire networks – but there aren’t enough situations like these to support the costs of the development and marketing of a potential mass-market technology such as Empower.

 Of course, the problem with running a community energy solution for 25,000 customers is that the levels of trust and engagement that characterise smaller communities are long gone with projects of this scale. The challenge, therefore, is to find ways of building trust across much larger numbers of customers or to bring down the cost of complying with regulations. The good news is that there are signs that the latter is beginning to happen. The government and the UK energy regulator, Ofgem, have made limited attempts to make the process cheaper – for example, they published a Community Energy Strategy in January 2014, which included the concept of a ‘licence lite’ for community-based energy companies. More practically, the continued entry of new players into the energy market is resulting in greater willingness by incumbents to innovate. Ovo and First Utility, for example, have interesting offers to communities – including ‘white label’ community energy models – and on using smart energy technology.

Meanwhile, the team behind Empower is already thinking beyond its Wiltshire pilot to a world in which community-level optimisation of energy systems is the norm. Encraft and e2E have just started a second project – also funded by Innovate UK through the Energy Catalyst scheme – to develop a sub-station-level control algorithm that will make it possible for the distribution networks to manage multiple community energy schemes across a city or sub-region. The emerging world of smart networks and smart grids is creating significant opportunities for technical and commercial innovation across the world.

MATTHEW RHODES is managing director of Encraft.

PAULA QUINTELA is project technical lead for Empower at e2E Services.

1 and 2 New Ludgate

2015-06-03T15:10:58Z

CIBSE:

Article from the June 2015 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Phil Thompson.

Limited space and strict noise requirements led to a compact, enclosed chiller being specified for an office scheme at 1 and 2 New Ludgate, in central London. 

The strict noise requirements of Land Securities’ commercial development at 1 and 2 New Ludgate, in London, helped to determine the specification of the chillers for the project. Air conditioning manufacturer Carrier worked closely with the client, consultant and contractor, SRW, to develop a compact, energy efficient design that enabled the chillers to be located in a restricted space. As a result, the chillers could be mounted on the rooftop, rather than in the basement, which was where the plant was located in the original design. This gave Land Securities more usable commercial space. The chiller manufacturer designed and built a custom package to enclose the chillers and reduce the amount of noise. The condensers are specifically configured to resist damage from hailstorms that can otherwise create significant, accumulating, impact damage to the coils and will reduce their performance.

Air conditioning for the buildings is supplied by six 930 kW (nominal) chillers with VSD-controlled screw compressors, alongside six smaller chillers with scroll compressors. The project included a bespoke pump, control and chiller sequencing package. ‘The software was programmed in-house and designed to maximise energy efficiency and air conditioning performance, as well as extend the working life of the chillers by careful run-time sequencing,’ says Danny Lear, specification and solutions manager at Carrier UK.

‘We were able to carry out full witness testing of working chillers at our facility in France, ensuring the solution met the specification fully.’ After installation, Carrier’s service team will, under a full-maintenance contract, ensure the chillers are maintained at peak performance level. The six screw compressor chillers are supplied with integral control that combines variable-speed condenser fans with variable- speed screw compressors, enabling close matching of cooling output to current load conditions. The constant control of the onboard intelligent control system, claims Carrier, enables the chiller to operate with very good part-load efficiency. 

With the ability to vary both condenser fan speed and compressor speed in response to constantly changing demand, the chiller can continue to operate in its ‘sweet spot’ in terms of performance and energy efficiency. Carrier asserts it delivers a full-load energy efficiency ratio (EER) of up to 3.4 and a European seasonal energy efficiency ratio (ESEER) up to 4.9. Through a control system, building owners can monitor and log performance data from the chiller via a web browser. Newly introduced software optimises use of compressors, fans and cooling circuits. It does this by constantly calculating the most efficient fan speed and water-flow rate, based on the current load and ambient conditions, and controls them to main appropriate refrigerant operating pressures through continuous feedback and adjustment.

For the full article on the [http://www.designingbuildings.co.uk/wiki/CIBSE CIBSE] website click [http://www.designingbuildings.co.uk/w/index.php?title=Www.cibsejournal.com&action=edit&redlink=1 here].

1 and 2 New Ludgate

2015-06-03T15:09:55Z

CIBSE:

1 and 2 New Ludgate

2015-06-03T15:09:22Z

CIBSE: Created page with " Article from the June 2015 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Phil Thompson. Limited space and strict noise requirements led to a com..."

Article from the June 2015 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Phil Thompson. 

Limited space and strict noise requirements led to a compact, enclosed chiller being specified for an office scheme at 1 and 2 New Ludgate, in central London. 

The strict noise requirements of Land Securities’ commercial development

at 1 and 2 New Ludgate, in London, helped to determine the specification of the chillers for the project. Air conditioning manufacturer Carrier worked closely with the client, consultant and contractor, SRW, to develop a compact, energy efficient design that enabled the chillers to be located in a restricted space. As a result, the chillers could be mounted on the rooftop, rather than in the basement, which was where the plant was located in the original design. This gave Land Securities more usable commercial space. The chiller manufacturer designed and built a custom package to enclose the chillers and reduce the amount of noise. The condensers are specifically configured to resist damage from hailstorms that can otherwise create significant, accumulating, impact damage to the coils and will reduce their performance.

Air conditioning for the buildings is supplied by six 930 kW (nominal) chillers with VSD-controlled screw compressors, alongside six smaller chillers with scroll compressors. The project included a bespoke pump, control and chiller sequencing package. ‘The software was programmed in-house and designed to maximise energy efficiency and air conditioning performance, as well as extend the working life of the chillers by careful run-time sequencing,’ says Danny Lear, specification and solutions manager at Carrier UK.

‘We were able to carry out full witness testing of working chillers at our facility in France, ensuring the solution met the specification fully.’ After installation, Carrier’s service team will, under a full-maintenance contract, ensure the chillers are maintained at peak performance level. The six screw compressor chillers are supplied with integral control that combines variable-speed condenser fans with variable- speed screw compressors, enabling close matching of cooling output to current load conditions. The constant control of the onboard intelligent control system, claims Carrier, enables the chiller to operate with very good part-load efficiency. 

With the ability to vary both condenser fan speed and compressor speed in response to constantly changing demand, the chiller can continue to operate in its ‘sweet spot’ in terms of performance and energy efficiency. Carrier asserts it delivers a full-load energy efficiency ratio (EER) of up to 3.4 and a European seasonal energy efficiency ratio (ESEER) up to 4.9. Through a control system, building owners can monitor and log performance data from the chiller via a web browser. Newly introduced software optimises use of compressors, fans and cooling circuits. It does this by constantly calculating the most efficient fan speed and water-flow rate, based on the current load and ambient conditions, and controls them to main appropriate refrigerant operating pressures through continuous feedback and adjustment.

Please go to

CIBSE Case Study: Christchurch International Airport

2015-05-13T10:20:09Z

CIBSE:

''Article from the May 2015 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Andy Pearson.''

Christchurch International Airport’s new terminal features a water source heat pump system with a payback period of only two years. Andy Pearson looks at an innovative system that triumphed in the International Project of the Year category at the CIBSE Building Performance Awards 2015. The new three-storey terminal at New Zealand’s Christchurch International Airport was the first major infrastructure project to be completed on the South Island after the devastating earthquakes of 2010 and 2011. It is fitting, then, that the 30,000m2 building relies on artesian water, abstracted from beneath the Earth’s surface, to provide an innovative, energy efficient, cost-effective and environmentally benign heating and cooling solution. The artesian system was designed by the New Zealand office of multinational consultancy Beca. Since the completion and opening of the NZ$237m (£121m) terminal in 2013, it has dramatically reduced the operational costs of the building and its dependency on fossil fuels. The airport operating company has been so impressed with the cost savings that it is implementing a similar artesian water-based set-up at the airport’s existing international terminal. 

The system’s success is not confined to the airport; artesian arrangements for sustainable heating and cooling are under design or in construction at a number of other developments in the city. This potential legacy was recognised by the judges of the CIBSE Building Performance Awards 2015, who gave top honours to the scheme in the International Project category. They described the artesian solution as: ‘An innovative application, with very good collaboration and strong ongoing involvement, and lots of potential for wider involvement.’ Work started on the scheme in 2005. Along with architect Warren and Mahoney, in association with Hassell (Australia), the firm designed a new terminal – incorporating an integrated domestic and international check-in – to sit on the site of the original 1960s domestic terminal. It was to be constructed in phases as the original terminal was progressively demolished, to make sure the airport could continue to operate. As a consequence of this phased construction, the services had to be designed to ensure the new terminal’s plantrooms and services were up and running before the existing ones were dismantled. ‘The first stage of the new construction had to contain the central plant to enable the new terminal to operate as a stand-alone building,’ explains Justin Hill, Beca’s technical director, building services. As subsequent construction phases were completed, the new systems were extended to service these too. 

 ‘The new terminal had to be designed so that its building services could be extended as new areas were built; this included, for example, the use of differential pressure control valves on the heating and chilled water systems, so the operational areas did not need to be recommissioned as new areas were constructed,’ Hill adds. The client’s brief for the integrated terminal was for it to be as energy efficient and sustainable as possible within the constraints of the budget. ‘The use of artesian water was always on the cards as the existing international terminal uses it directly in a pre-cooling application, ’ Hill says. ‘The challenge for Beca was to make better use of artesian water and to eliminate the need for fossil fuels. ’ The elegance of the system is that it uses standard equipment – including three chillers – which have been confi gured to enable them to provide simultaneous heating and cooling, with the ability to recover and redistribute energy around the building. ‘The idea arose when Keith Paterson (business director for Canterbury Rebuild) realised the temperature of the artesian water – at 10-12°C – was perfect for a heat pumptype application and confi gured the system in a similar manner to that used in the thermal storage industry, which Keith had experience of from his work in Singapore, ’ Hill recollects. The system comprises two principal circuits: a closed-loop secondary system and an open artesian water circuit. In the open circuit, artesian water is abstracted from five wells, which draw water from a major aquifer flowing 35m beneath the terminal. There is provision to add a sixth well, should the capacity of the system need to be increased in the future. 

 These boreholes are located 50-75m apart, and relatively close to the terminal, tokeep pipe runs to a minimum. Abstractedartesian water passes through any one – orall three – of the heat exchangers beforebeing discharged back into the ground via a 5m-deep soak pit beneath the car park. Nowater is consumed by the system; the onlyeffect is that the temperature of the returned water will vary from 7-20°C, depending on the plant’s mode of operation. 

 With the closed-loop s ystem, water circulates through the secondary side of the heat exchangers, the air handling unit heating and cooling coils and, if required, the chillers when they operate as water-towater heat pumps. When cooling loads are low, water from the aquifer can meet the terminal’s cooling requirements. This avoids the need for any mechanical refrigeration. Areas requiring year-round cooling have coils sized to enable them to use artesian temperature cooling year-round, to minimise the use of the chillers. With higher heating or cooling loads, the artesian water is used as part of a mechanical refrigeration system, with the chillers working as geothermal heat pumps, thereby enabling the system to provide heating and cooling simultaneously, and in any proportion, from every chiller. In this mode, the heat energy removed by the chiller in the evaporator to generate chilled water is used to provide heat. Rather than reject the heat energy – generated as a by-product of providing cooling through cooling towers to the atmosphere, the chiller’s condenser water is used as a heat source for the terminal’s heating circuit. This enables the system simultaneously to generate heating and cooling. When heat is not needed by the terminal, it is rejected to the artesian water via the plate heat exchangers. ‘When we want to generate heat, if there is no requirement to chill the terminal’s cooling water system we, effectively, chill the artesian water, ’ explains Hill. ‘To my knowledge, there are no artesian-based systems elsewhere, of this size and nature, configured to provide simultaneous heating, cooling and artesian temperature cooling with the ability to recover and redistribute energy around the building. ’ 

 Comprehensive engineering analysis was undertaken to assess the most appropriate solutions and to provide confidence that the system would achieve the design objectives. This resulted in the central plant having four modes of operation: artesian cooling; mechanical cooling; heating; and simultaneous heating and cooling (see panel ‘Four modes of operation’ below). Water temperatures in heating mode were analysed to optimise

the flow and return temperatures. Operational efficiencies and capital cost – along with reliability and plant longevity – were all considered at various LTHW temperatures. The analysis showed the optimal temperature for heating to be 40°C flow and 25°C return. In addition to heat from the chillers, heat is recovered from two 1MW electrical generators, when they operate, and is added to the LTHW system. The generators were installed to ensure the terminal can continue to operate in a power cut and – at the request of the terminal’s electricity supply company – to operate during periods of peak electrical demand. The chillers are more than capable of supplying sufficient heat for the building, but the heat is recovered because it is costeffective to do so. 

 The heating and chilled water systems have been designed with floating water temperature set-points to maximise efficiencies of the central plant. The heating water circuit flow temperature has been designed to float between 30°C and 40°C, depending on the heating requirement of the building. If, for example, there is a reduction in the building’s heating demand, the heating water flow temperature set-point is reduced gradually until the temperature

of the heating water meets the demands of the building. This improves the efficiency of the chiller as a heat source for the building. The company spent a long time developing and bench-testing a robust control strategy for the artesian system. ‘We did not set out to provide the optimum and most efficient control strategy, but rather one that was reasonably efficient, and – most importantly – stable and robust, and capable of handling all possible scenarios,’ says Hill. ‘Using this as a base, the control strategy can be optimised and the system efficiency improved, based on actual building performance and usage.’ In

July 2013, four months after completion of the terminal, the new and existing international buildings’ energy consumption – which includes all energy sources, equipment and tenancy loads – was measured at 27.97kWh/(m2·month). As part of a soft landings approach (apt for an airport) over the following year, the engineers – after fine-tuning – reduced this figure to 27.01kWh/(m2·month), which equates to an annual figure of 324kWh/m2.

 Once the system was complete and its performance established, Beca undertook a study of the performance of the central plant system. During the period analysed, the total annual heating consumption was 2,860MWh for the new terminal, while annual cooling was 3,170MWh. The electrical input to the chillers was 901MWh, which equates to 34.7kWh/m2 for the 26,000m2 of conditioned floor area, giving an overall coefficient of performance (CoP) of 6.7 for the central chiller system, excluding pumping energy. This corresponds to CO2 emissions of 5.9kgCO2/m2, based on the New Zealand Green Building Council Green Star calculator. The study showed that, with some modifications to the chiller control strategy, annual central plant energy could be reduced by 100MWh – approximately 10% of the chiller input power – which, excluding pumping energy, would increase the overall central chiller system CoP to 7.5. The cost of the artesian-based system over and above a conventional boiler, chiller, cooling tower system was approximately NZ$750,000 (£375,000). Based on in-use data of 6,030MWh of thermal and 901MWh of electrical input energy, payback on the solution is approximately two years. 

 Hill says that the payback period alone has ‘justified retaining the system, rather than opting for a cheaper conventional solution during the project’s various rounds of value engineering’. The final word on the scheme should be left to Mike Parker, the terminal’s facilities manager: ‘We are ecstatic with the artesian heating and cooling system. ‘During the many rounds of value management, the system came under heavy scrutiny and pressure to be dropped for a more conventional and cheaper solution. Thankfully, Beca and Christchurch Airport were well aligned and retained the system, which is performing better than we could have hoped.’ 

== Four Modes of Operation ==
*Mode 1: Artesian cooling. Artesian water at 10-12°C is used to cool the secondary circuit directly to reduce, or even avoid, the need to run the chillers
*Mode 2: Mechanical cooling. The chillers provide chilled water, with the artesian water used to remove heat from the condensers
*Mode 3: Heating. Artesian-temperature water is used as the heat energy source for the chiller evaporators to generate hot condenser water for use in the heating circuits
*Mode 4: Simultaneous heating and cooling. Recovering and redistributing energy around the building, using condenser-heated water in the secondary heating circuit and evaporatorchilled water in the secondary cooling circuit, with artesian water used as the heat source or heat sink, depending on the imbalance between cooling and heating loads.

For the full article on the CIBSE website click [[www.cibsejournal.com|here]].

CIBSE Case Study: Christchurch International Airport

2015-05-13T10:18:00Z

CIBSE: Created page with " ''Article from the May 2015 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Andy Pearson.'' Christchurch International Airport’s new terminal fe..."

''Article from the May 2015 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Andy Pearson.'' 

Christchurch International Airport’s new terminal features a water source heat pump system with a payback period of only two years. Andy Pearson looks at an innovative system that triumphed in the International Project of the Year category at the CIBSE Building Performance Awards 2015. The new three-storey terminal at New Zealand’s Christchurch International Airport was the first major infrastructure project to be completed on the South Island after the devastating earthquakes of 2010 and 2011. It is fitting, then, that the 30,000m2 building relies on artesian water, abstracted from beneath the Earth’s surface, to provide an innovative, energy efficient, cost-effective and environmentally benign heating and cooling solution. The artesian system was designed by the New Zealand office of multinational consultancy Beca. Since the completion and opening of the NZ$237m (£121m) terminal in 2013, it has dramatically reduced the operational costs of the building and its dependency on fossil fuels. The airport operating company has been so impressed with the cost savings that it is implementing a similar artesian water-based set-up at the airport’s existing international terminal. 

The system’s success is not confined to the airport; artesian arrangements for sustainable heating and cooling are under design or in construction at a number of other developments in the city. This potential legacy was recognised by the judges of the CIBSE Building Performance Awards 2015, who gave top honours to the scheme in the International Project category. They described the artesian solution as: ‘An innovative application, with very good collaboration and strong ongoing involvement, and lots of potential for wider involvement.’ Work started on the scheme in 2005. Along with architect Warren and Mahoney, in association with Hassell (Australia), the firm designed a new terminal – incorporating an integrated domestic and international check-in – to sit on the site of the original 1960s domestic terminal. It was to be constructed in phases as the original terminal was progressively demolished, to make sure the airport could continue to operate. As a consequence of this phased construction, the services had to be designed to ensure the new terminal’s plantrooms and services were up and running before the existing ones were dismantled. ‘The first stage of the new construction had to contain the central plant to enable the new terminal to operate as a stand-alone building,’ explains Justin Hill, Beca’s technical director, building services. As subsequent construction phases were completed, the new systems were extended to service these too. 

 ‘The new terminal had to be designed so that its building services could be extended as new areas were built; this included, for example, the use of differential pressure control valves on the heating and chilled water systems, so the operational areas did not need to be recommissioned as new areas were constructed,’ Hill adds. The client’s brief for the integrated terminal was for it to be as energy efficient and sustainable as possible within the constraints of the budget. ‘The use of artesian water was always on the cards as the existing international terminal uses it directly in a pre-cooling application, ’ Hill says. ‘The challenge for Beca was to make better use of artesian water and to eliminate the need for fossil fuels. ’ The elegance of the system is that it uses standard equipment – including three chillers – which have been confi gured to enable them to provide simultaneous heating and cooling, with the ability to recover and redistribute energy around the building. ‘The idea arose when Keith Paterson (business director for Canterbury Rebuild) realised the temperature of the artesian water – at 10-12°C – was perfect for a heat pumptype application and confi gured the system in a similar manner to that used in the thermal storage industry, which Keith had experience of from his work in Singapore, ’ Hill recollects. The system comprises two principal circuits: a closed-loop secondary system and an open artesian water circuit. In the open circuit, artesian water is abstracted from five wells, which draw water from a major aquifer flowing 35m beneath the terminal. There is provision to add a sixth well, should the capacity of the system need to be increased in the future. 

 These boreholes are located 50-75m apart, and relatively close to the terminal, tokeep pipe runs to a minimum. Abstractedartesian water passes through any one – orall three – of the heat exchangers beforebeing discharged back into the ground via a 5m-deep soak pit beneath the car park. Nowater is consumed by the system; the onlyeffect is that the temperature of the returned water will vary from 7-20°C, depending on the plant’s mode of operation. 

 With the closed-loop s ystem, water circulates through the secondary side of the heat exchangers, the air handling unit heating and cooling coils and, if required, the chillers when they operate as water-towater heat pumps. When cooling loads are low, water from the aquifer can meet the terminal’s cooling requirements. This avoids the need for any mechanical refrigeration. Areas requiring year-round cooling have coils sized to enable them to use artesian temperature cooling year-round, to minimise the use of the chillers. With higher heating or cooling loads, the artesian water is used as part of a mechanical refrigeration system, with the chillers working as geothermal heat pumps, thereby enabling the system to provide heating and cooling simultaneously, and in any proportion, from every chiller. In this mode, the heat energy removed by the chiller in the evaporator to generate chilled water is used to provide heat. Rather than reject the heat energy – generated as a by-product of providing cooling through cooling towers to the atmosphere, the chiller’s condenser water is used as a heat source for the terminal’s heating circuit. This enables the system simultaneously to generate heating and cooling. When heat is not needed by the terminal, it is rejected to the artesian water via the plate heat exchangers. ‘When we want to generate heat, if there is no requirement to chill the terminal’s cooling water system we, effectively, chill the artesian water, ’ explains Hill. ‘To my knowledge, there are no artesian-based systems elsewhere, of this size and nature, configured to provide simultaneous heating, cooling and artesian temperature cooling with the ability to recover and redistribute energy around the building. ’ 

 Comprehensive engineering analysis was undertaken to assess the most appropriate solutions and to provide confidence that the system would achieve the design objectives. This resulted in the central plant having four modes of operation: artesian cooling; mechanical cooling; heating; and simultaneous heating and cooling (see panel ‘Four modes of operation’ below). Water temperatures in heating mode were analysed to optimise

the flow and return temperatures. Operational efficiencies and capital cost – along with reliability and plant longevity – were all considered at various LTHW temperatures. The analysis showed the optimal temperature for heating to be 40°C flow and 25°C return. In addition to heat from the chillers, heat is recovered from two 1MW electrical generators, when they operate, and is added to the LTHW system. The generators were installed to ensure the terminal can continue to operate in a power cut and – at the request of the terminal’s electricity supply company – to operate during periods of peak electrical demand. The chillers are more than capable of supplying sufficient heat for the building, but the heat is recovered because it is costeffective to do so. 

 The heating and chilled water systems have been designed with floating water temperature set-points to maximise efficiencies of the central plant. The heating water circuit flow temperature has been designed to float between 30°C and 40°C, depending on the heating requirement of the building. If, for example, there is a reduction in the building’s heating demand, the heating water flow temperature set-point is reduced gradually until the temperature

of the heating water meets the demands of the building. This improves the efficiency of the chiller as a heat source for the building. The company spent a long time developing and bench-testing a robust control strategy for the artesian system. ‘We did not set out to provide the optimum and most efficient control strategy, but rather one that was reasonably efficient, and – most importantly – stable and robust, and capable of handling all possible scenarios,’ says Hill. ‘Using this as a base, the control strategy can be optimised and the system efficiency improved, based on actual building performance and usage.’ In

July 2013, four months after completion of the terminal, the new and existing international buildings’ energy consumption – which includes all energy sources, equipment and tenancy loads – was measured at 27.97kWh/(m2·month). As part of a soft landings approach (apt for an airport) over the following year, the engineers – after fine-tuning – reduced this figure to 27.01kWh/(m2·month), which equates to an annual figure of 324kWh/m2.

 Once the system was complete and its performance established, Beca undertook a study of the performance of the central plant system. During the period analysed, the total annual heating consumption was 2,860MWh for the new terminal, while annual cooling was 3,170MWh. The electrical input to the chillers was 901MWh, which equates to 34.7kWh/m2 for the 26,000m2 of conditioned floor area, giving an overall coefficient of performance (CoP) of 6.7 for the central chiller system, excluding pumping energy. This corresponds to CO2 emissions of 5.9kgCO2/m2, based on the New Zealand Green Building Council Green Star calculator. The study showed that, with some modifications to the chiller control strategy, annual central plant energy could be reduced by 100MWh – approximately 10% of the chiller input power – which, excluding pumping energy, would increase the overall central chiller system CoP to 7.5. The cost of the artesian-based system over and above a conventional boiler, chiller, cooling tower system was approximately NZ$750,000 (£375,000). Based on in-use data of 6,030MWh of thermal and 901MWh of electrical input energy, payback on the solution is approximately two years. 

 Hill says that the payback period alone has ‘justified retaining the system, rather than opting for a cheaper conventional solution during the project’s various rounds of value engineering’. The final word on the scheme should be left to Mike Parker, the terminal’s facilities manager: ‘We are ecstatic with the artesian heating and cooling system. ‘During the many rounds of value management, the system came under heavy scrutiny and pressure to be dropped for a more conventional and cheaper solution. Thankfully, Beca and Christchurch Airport were well aligned and retained the system, which is performing better than we could have hoped.’ 

== Four Modes of Operation ==
*Mode 1: Artesian cooling. Artesian water at 10-12°C is used to cool the secondary circuit directly to reduce, or even avoid, the need to run the chillers
*Mode 2: Mechanical cooling. The chillers provide chilled water, with the artesian water used to remove heat from the condensers
*Mode 3: Heating. Artesian-temperature water is used as the heat energy source for the chiller evaporators to generate hot condenser water for use in the heating circuits
*Mode 4: Simultaneous heating and cooling. Recovering and redistributing energy around the building, using condenser-heated water in the secondary heating circuit and evaporatorchilled water in the secondary cooling circuit, with artesian water used as the heat source or heat sink, depending on the imbalance between cooling and heating loads.

To read the full article, please click here.

CIBSE Case Study: Westborough Academy

2015-04-07T09:34:38Z

CIBSE: Created page with " ''Article from the April 2015 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Gareth Holden.'' Westborough Academy, in Essex, won the Refurbishmen..."

''Article from the April 2015 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Gareth Holden.'' 

Westborough Academy, in Essex, won the Refurbishment Project of the Year at the recent CIBSE Building Performance Awards. Andrew Brister looks at how OR Consulting Engineers collaborated with the architect to upgrade facilities at the Edwardian school, and picks out the key lessons learned. The glory days for the Building Schools for the Future programme may be over, but there is still plenty of work in the sector for building services specialists. With capital expenditure squeezed, the emphasis in the coalition’s Priority School Building Programme is now on improvement of existing facilities. A recent phased renovation of the Edwardian school buildings of Westborough Academy, in Westcliff -on-Sea, Essex, off ers a template for the many similar structures up and down the country. Westborough picked up the a ccolade for Refurbishment Project of the Year (up to £5m) at the recent CIBSE Building Performance Awards – a proud moment for building services fi rm OR Consulting Engineers. ‘It was a privilege to work on the project,’ says managing director, Peter Roberts. ‘With recent funding cuts to school capital programmes, refurbishment and Westborough Academy, in Essex, won the Refurbishment Project of the Year at the recent CIBSE Building Performance Awards. Andrew Brister looks at how OR Consulting Engineers collaborated with the architect to upgrade facilities at the Edwardian school, and picks out the key lessons learned redevelopment projects will be increasingly important methods of improving school environments with lower budgets – but they also provide an excellent opportunity to add value to existing buildings and save the energy required to demolish and rebuild new schools.’ Westborough Primary School is a threeform- entry primary school and nursery. The original Edwardian facilities have been added to – and extended – over the years, with new playgrounds and classroom blocks, as well as the award winning Cardboard Building. However, the older building stock and its building services were nearing the end of their useful life, so the school looked for a refurbishment that would reflect its sustainable ethos. With a rising birth rate in the area, the improved facilities would also allow for an increased pupil intake. Enter Cottrell and Vermeulen Architects – the partnership has worked with the school since 1992 on a number of infrastructure projects – and OR Consulting Engineers. The result is what the team has dubbed the ‘Zero Carbon Masterplan Refurbishment’ scheme – a three-phased approach to realising a low carbon refurbishment of the existing Edwardian structures. ‘What’s interesting is that there has been a masterplan for the overall scheme, with more phases coming on stream as more money becomes available,’ says Roberts. ‘Too often, school refurbishments are done piecemeal, with isolated packages of work and nothing to knit them together.’ The original masterplan goes back to 2009 and was due to be complet ed in April 2013 as funding was obtained over time. The Phase 1 works (£1.3m) were funded by the Zero Carbon Task Force of the then Department for Children, Schools and Families (DCSF, now the Department for Education), Southend Local Education Authority (LEA) and Balfour Beatty, and were completed in March 2011. The Phase 2 works (£1.2m) were funded by the Academies Capital Maintenance Fund and Southend LEA, and completed in May 2012. The final stage of the masterplan project (Phase 3) was completed in April 2013. The DCSF was keen to use the school as an exemplar of how older buildings can be refurbished with a low energy agenda, to meet the demands of contemporary education. ‘The masterplan project provided a test bed for ways of refurbishing older school buildings in a sustainable manner and a model for future schemes,’ says Roberts. ‘The project delivers information on the effectiveness of carbonreduction strategies that can be applied to typical existing primary school buildings.’ 

Phase 1 of the masterplan resulted in the introduction of renewable technologies (biomass and solar photovoltaics) as part of a Lean, Mean and Green strategy (see box); the upgrade of the fabric in certain blocks; and the creation of a multi-use hall that could be made into one large space or subdivided into seven smaller areas using folding, acoustic partitions. As further blocks were refurbished in Phases 2 and 3, the extension of the low carbon heating system increased the base load of the biomass boiler and optimised running hours. In addition, water management strategies – such as rainwater recycling and water-efficient sanitary fittings – were used to reduce water consumption. 

The issue of accommodating renewables in a dense, urban area, with housing on all sides, needed careful consideration. ‘Reducing carbon emissions to zero through refurbishment of an existing building, based solely on improvements to building fabric and services, has been shown to be difficult,’ says Roberts. ‘To further improve sustainability, renewable sources of energy are essential. Depending on the context of the project there are limits on which technologies can be used. In this case, our original planning application included a wind turbine on the site, which proved to be untenable following opposition from local residents.’

Photovoltaic panels have been neatly integrated on a walkway that the children use to travel between classrooms. The Lean and Mean measures reduced the electrical load of the school by 30%. The 400m2 of PV panels installed can supply 70% of the demand, leading to a carbon reduction estimated at 17,000kgCO2 per annum. A biomass boiler has been included as the primary heat source for the school, with wood pellets chosen as the fuel. Wood pellets have a

high calorific value – approximately 3,000kWh/m3 – so the store size could be reduced compared with what would be needed for a wood-chip boiler. Based on a two-week supply during peak heating season, approximately 3m3 of storage space – excluding access area – is required. This could be accommodated in an old toilet area. Gas boiler backup allows flexibility in supply. The 45kW biomass boiler is sized to meet one-third of the peak load. Because of the low carbon factor of localised biomass boiler systems (0.025kgCO2/kWh), the biomass system is estimated to save two-thirds of the annual heating carbon emissions, which equates to approximately 17,000kgCO2 per annum. The biomass system is enthusiastically looked after by one of the teachers – testament to the effort put in up front to make sure the school understands how its new facilities are meant to operate (see Soft landings panel, overleaf).

== Performance feedback ==

After completion of Phase 1, Buro Happold’s Alternative Technology and Sustainability Unit was brought in to assess the building’s performance, and reported a 30% reduction in carbon emissions. In terms of energy consumption, the refurbished areas of the Edwardian school perform 17% better than a typical primary school, based on ECON 73 benchmarks. Critics will point to long payback periods – in excess of 30 years for the biomass boiler and solar PV. 

 ‘Generally, the paybacks are uneconomic,’ admits Roberts. ‘The fabric improvement measures have paybacks in the region of 23 years. In a financial sense, this improvement is not attractive in isolation, but when this maintenance-free measure is considered against the lifespan of a renovated building – which has already served its community for a century – it is a more persuasive proposition.’ The DSCF continued to support the adoption of these technologies regardless of the financial performance, because it wanted to understand:
*How the technologies performed in practice
*The educational value of children engaging with the operation and performance of these technologies
*The maintenance burden over the life-cycle of the building
*The robustness of the adoption of some technologies in a primary school environment.

The fact that the refurbishment was split into phases meant that the team was able to learn from the initial phase and improve as the project progressed. ‘The later phases were much quicker as we learn ed about the necessary detailing of the thermal insulation, dry lining and the best routing for services in an Edwardian building,’ says Roberts. The collaborative nature of the project has also reaped other rewards: the team was working together on other schools projects, as well as a low carbon Hindu temple in Hertfordshire. Westborough promises to deliver much-needed feedback on what works and what doesn’t as the nation looks to revamp its ageing building stock. Let’s hope designers do their homework and follow some of the lessons learn ed from this award-winning refurbishment.

== Lean, Mean and Green ==

The carbon-reduction strategy at Westborough is based on the adoption of ‘Lean, Mean and Green’ measures.
*The‘Lean’ strategy reduced energy demands, improving the existing building fabric by internally lining walls and roofs with thermal and acoustic insulation, refurbishing windows and improving building air-tightness.
*The ‘Mean’ strategy produced savings through the introduction of: energy efficient lighting; lighting controls; heat-recovery ventilation; powerfactor correction; voltage correction; sub-metering; condensing boilers to supply supplementary heating to the biomass system; and new controls for the building services.
*The ‘Green’ strategy introduced renewable energy systems to the project, namely biomass heating and photovoltaic panels.

== Soft Landings ==

The design team carried out a series of presentations to the client, teaching staff , local authority and DCSF at key stages of the project. The aim was to inform and defi ne the developing brief, and to begin educating users on how to operate and occupy their new building effi ciently. Towards the end of the project, a softlanding process was employed by the design team and contractor to communicate the key principles of the design, and the key environmental strategies required for effi cient operation. Dedicated training sessions – attended by the design team, contractors and staff – were carried out for the biomass heating installation and controls. The team also offered support to the school post-completion, to ensure a smooth transition into occupation for the client. ‘This process has paid real dividends and the school has taken pride in its new buildings,’ says Peter Roberts, of OR Consulting Engineers. As well as teacher involvement in running the biomass installation, data from the submetering and PV display panel ha ve been used in the teaching of the maths curriculum. 

For the full article on the CIBSE website [[www.cibsejournal.com|click here]].

CIBSE Case Study: Bosco Verticale

2015-02-26T16:09:34Z

CIBSE: Created page with " Article from the March 2015 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Alex Smith. The drama of Bosco Verticale's forested facade may be gaini..."

Article from the March 2015 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Alex Smith. 

The drama of Bosco Verticale's forested facade may be gaining international attention, but it is the innovative use of heat-pump technology that is helping to slash heating and cooling costs at these seminal Milanese apartment blocks. The 19- and 27-storey towers of Milan’s Bosco Verticale apartment block came into full bloom for the first time last summer. Hundreds of varieties of trees and shrubs spilled over the balconies of the 111 apartments to ensure the scheme lived up to the promise in its name – Bosco Verticale, Italian for ‘vertical forest’. The external appearance of the towers follows the seasons, and when you approach in mid-winter – after the deciduous trees have shed their leaves – the verticale is not so verde. Indeed, it’s difficult to distinguish the outline of the branches against the building’s dark façade. 

While the towers may lose their ‘herb appeal’ during the colder months, the choice of deciduous trees is an important part of the environmental strategy. In the winter, the bare branches allow the sun to warm apartment interiors through the large floorto- ceiling windows, so reducing the heating requirements. In the summer, trees in full leaf provide shading, which minimises solar gain and reduces cooling needs. 

It’s an elegant and simple concept, which cuts the buildings’ energy use, while providing Milanese with a green vertical oasis in the city’s built-up centre. However, the trees are only one part of the innovative environmental strategy for the project. Designed by architect Stefano Boeri, the project is one of a number of new schemes in the Porta Nuova district of Milan that take advantage of a large aquifer under the city for heating and cooling. These include the Unicredit skyscraper, the tallest building in Italy. 

 Using ground source heat pumps to access the aquifer, the building services engineer, Planning – known in the UK as Rethinking Energy – is balancing the cooling and heating demands to minimise energy use at Bosco Verticale. Hilson Moran, the original building services engineer on the project, specified two Climaveneta Integra units, which can each provide 556 kW of cooling and 589 kW of heating. They have the ability simultaneously to provide heat and cooling – so, for example, hot water for underfloor heating can be provided to heat north-facing rooms, at the same time as apartments in south-facing rooms are cooled via ducted fan coil units. The radiant floor is also cooled through a heat exchanger connected to the aquifer loop, which helps lower the overall cooling load. Air handling units are positioned at the top and bottom of the larger tower to balance air flows. 

The heat pumps work most efficiently during the spring and autumn, when different rooms in the tower need to be cooled and heated simultaneously. When the unit provides cooling for overheating rooms, the heat rejected from the condenser can be used to bring room temperatures in other parts of the towers up to the desired setpoint. By recovering heat and coolth simultaneously, the units can balance the cooling and heating loads, and can improve the COP of the heat pump. To measure the efficiency of the units, Climaveneta uses the total efficiency ratio (TER), which is the ratio of the sum of the heating and cooling power, and electrical output. The coefficient of performance is usually used to measure the effi ciency of heat pumps, but this is a ratio for either heating or cooling, not for both. Two small gas boilers in a basement plant room, rather than the heat pumps, provide domestic hot water , because – when the building was designed – it was felt that maintaining the gas boilers’ ability to keep water temperatures above 60°C was the best way to prevent the growth of legionella bacteria. 

Planning building services engineer Giuseppe Medeghini says he would consider using a heat pump to supply domestic hot water if the building was being designed today, even though they can only provide water up to 45°C. ‘There are now ways to prevent legionella using chemicals, and they are cheaper and more effective,’ he says. ‘Using a heat pump works particularly well during the summer months, where all the excess heat coming from the cooling process, can be captured and used to provide domestic hot water .’ 

Medeghini says he would also consider using a second heat pump to produce domestic hot water up to 65°C, thereby doing away with the need for a storage vessel. ‘We now have much more fl exibility in choosing a system for domestic hot water,’ he says’. (See ‘Balancing act’ panel to find out how Planning is balancing loads using sprinkler tanks in its latest scheme). Heat pumps still have a part to play in providing domestic hot water at Bosco Verticale. They pre-heat water to 45°C , so the gas boiler doesn’t have to work so hard to boost the temperature to the required 65°C. Planning is currently fi nishing the commissioning phase of Bosco Verticale, and is hoping to secure an ongoing contract with the developer, Hines. 

‘Continuous monitoring is very important, especially on complex systems,’ says Medeghini. ‘Modern HVAC systems can bring important reductions in energy use, but they must be monitored and tweaked to guarantee these savings.’ The energy company is currently keeping tabs on a Climaveneta air source heat pump system at Palazzo Aporti, a Hines office refurbishment in central Milan. Using the heat pump manufacturers’ Clima Pro online monitoring system, the facilities managers can constantly access the performance of the heat pumps and the temperatures in the tenanted spaces, which are all metered. 

If Bosco Verticale has the same technology, Medeghini says that the HVAC system can be continuously optimised, reducing energy use and cutting tenants’ bills. These savings will at least help the residents pay for the pruning of the thousands of trees and plants that have helped create Milan’s showstopper. While the foliage is fabulous, the intelligent design of the HVAC cannot be overestimated when considering the impact on carbon reduction at Bosco Verticale. Medeghini estimates the system offers at least 35% savings over a traditional building. 

== Milan’s hidden energy source ==

Bosco Verticale is part of Milan’s Porta Nuova regeneration zone, which comprises a mix of retail, commercial and housing units, including the Cesar Pelli-designed Unicredit Tower, which – at 231m – is the tallest building in Italy. All the buildings on the estate use the same geothermal system as Bosco Verticale. There are three geothermal water loops on Porta Nuo va. On the ‘Garibaldi’ loop serving Bosco Verticale the water is extracted from 12 underground wells, and transported via a 350mm distribution ring. The apartment blocks use the same loop as the nearby offi ces occupied by Google . On the other side of the railway, another geothermal loop caters for the Unicredit Tower, plus a mix of other offices, and retail and residential units. Water is filtered, before passing through heat exchangers under Bosco Verticale and the office. Secondary circuits in the heat exchangers take the chilled and hot water from a basement plantroom into the buildings. 

 The combined peak heating loads for Bosco Verticale and the Google offi ce is expected to be 2,200kW, and the cooling load 1,400kW. Water from the Garibaldi loop is discharged into the Martes ana canal, unless its levels are too high, in which case the water is deviated to six wells that lead back to the aquifer. Permission for using the aquifer is lodged with the Milan province. It can take a year to receive a final licence, so these are lodged early in the construction process. The applicants have to state the amount of water they want to use in a year, and ensure that the return temperature of the water is within acceptable parameters – at Bosco Verticale the upper temperature limit is 25°C. 

== Balancing act ==

Planning is working on another scheme in Milan that uses a 150m3 sprinkler tank to store and recover heat – and cool it from water in the system – before returning it to the aquifer. This reduces the amount of water that needs to be pumped from the aquifer. ‘If the pool is between 10°C and 20°C, we do not use the aquifer. If it’s above or below, then we use the aquifer to rebalance,’ says Planning building services engineer Giuseppe Medeghini. ‘In the early part of the day, when heat is required in the rooms, the system cools the sprinkler tank water from 15°C to perhaps 11°C. The heat pump then doesn’t have to work so hard when cool air is required later in the day, when outdoor temperatures rise.’ 

== Branching out ==

The balconies of Bosco Verticale are planted with 800 trees – between three metres and nine metres tall – 5,000 shrubs and 11,000 perennials. The trees, chosen by landscape architect Laura Gatti, are mainly deciduous, which means the external appearance of the two towers alters as the leaves change colour over the seasons. The trees will grow to 9m in height and then stabilise. The plants are watered automatically through a centralised system that reuses water extracted from the aquifer. The greenery is maintained from balconies and external platforms, which are used for pruning hard-to-reach branches. Plant maintainance costs are covered in the service charge. 

For the full article on the [http://www.designingbuildings.co.uk/wiki/CIBSE CIBSE] website click here.

CIBSE Case Study: Everyman Theatre Liverpool

2015-02-02T17:04:32Z

CIBSE:

Article from the February 2015 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Andy Pearson. 

== Introduction ==

Four ventilation chimneys named John, Paul, George and Ringo are central to the environmental strategy at the Everyman Theatre in Liverpool, which wowed critics at the Stirling Prize. The judges’ citation for the winner of this year’s RIBA Stirling prize makes clear that Waterman Building Services’ low energy servicing strategy – as much as Haworth Tompkins’ striking architecture – was the reason for their decision to award the best building of the year prize to the Everyman Theatre, in Liverpool. They praised its ‘naturally ventilated auditoria’, applauded the use of concrete labyrinths to ‘supply and expel air’, and described the design as ‘exceptionally sustainable’. The judges’ comments should come as no surprise to the design team; from the outset, sustainability was integral to the concept of the new building . The original Everyman Theatre opened in 1964, converted from the shell of a 19th-century chapel. Over time, however, the fabric of this much-loved institution deteriorated badly, while the increasing needs of its users meant the space was no longer viable. Originally, the plan was to build a larger theatre on a new site, but Haworth Tompkins argued successfully for maintaining an important sense of continuity by reusing the existing, compact, Hope Street site. To accommodate the new building on an area of just 1,610m2 the shell of the existing structure was carefully dismantled to allow most of the chapel’s bricks to be salvaged for use in the theatre’s reincarnation. Haworth Tompkins designed the new Everyman Theatre to derive as much functionality from the building as possible, while incorporating the best-loved features of its predecessor – all within a similar volume. The outcome is that the building’s public spaces – including the foyer and bars – have been arranged in a series of half-level floors, set around the perimeter, to create what the architect describes as ‘a continuous winding promenade, from street to auditorium’. In addition to the main auditorium and the catering spaces, Haworth Tompkins has also managed to slot in numerous creative spaces, including a rehearsal room, workshops, an audio-visual studio, a writers’ room, and a community studio. Externally, the most striking architectural features are the theatre’s main, west-facing elevation, and four, giant, cylindrical chimneys, perched on the roof. The attention-grabbing west façade is formed from 105 movable, aluminium sunshades. These are set in three rows, running the length of the elevation, and each one features a life-size portrait of a contemporary Liverpool resident, cut out of the metal sheet. In contrast, the restrained red brick of the north, east and south elevations help the building sit comfortably with its listed neighbours. That same red brick is also used to form the four giant chimneys, which are a key component of the auditorium’s natural ventilation system. The 400 seat auditorium is at the heart of the 4,690m2 building, literally and metaphorically. It has been designed to accommodate a ‘thrust’ stage (one that extends into the audience), which is encompassed on three sides by seating to recreate the intimacy of the old Everyman Theatre. This familiarity is enhanced by the use of reclaimed bricks from the original theatre, which are exposed in the new auditorium’s walls. As well as giving the auditorium a worn, cosy ambience, the reclaimed bricks add thermal mass to the space, as part of the theatre’s ventilation strategy. ‘The client wanted a very, very sustainable, low energy theatre, so natural ventilation was seen as the obvious solution,’ says Jonathan Purcell, director of building services for Waterman’s, who was charged with developing the ventilation solution for the windowless, artificial environment of the theatre’s auditorium. ‘We had to find a way to ventilate what is essentially a black box.’ 

== Cooling the stalls ==

The design team’s aim with the auditorium ventilation strategy was, according to Purcell, ‘to provide a nice, clean, swept path for the air to enter the space at low level, then meet very little resistance as it is allowed to rise from low level to high level in the auditorium; and, finally, to provide a simple route out through the roof-top chimneys’. As a result, fresh air enters the building through an inlet louvre on Arad Street, a quiet road at the rear of the building. It then passes through acoustic attenuators and into a giant, concrete-encased plenum, constructed beneath the workshop area behind the theatre’s stage. ‘We’ve got a massive cavern of concrete in contact with the ground, which we use to cool the supply air in summer before it enters the auditorium,’ Purcell explains. From here, the air passes beneath the stage, through secondary attenuators, and into a horseshoe- shaped plenum beneath the banked rows of seating lining the auditorium walls. The fresh air finally enters the auditorium through a series of perforated grilles beneath the seating. Heat given off by the audience, and from the theatre lighting, increases the buoyancy of the air, causing it to rise upwards through the lighting gantries to an acoustically attenuated 2.5m-high exhaust air plenum. A giant duct, which doubles back on itself, then delivers the air from the plenum to the four louvred chimneys – nicknamed John, Paul, George and Ringo by the design team – where it is exhausted. For the system to work effectively, Waterman’s had to generate enough buoyancy to drive a sufficient quantity of air through the auditorium to keep conditions comfortable for the audience. The air inlet size and location was set – its dimensions defined by the street, basement and ground-floor slab levels. Building Regulations requirements for fresh air of 10 litres per second per person for a capacity audience of 450 people, plus 40 staff and actors, set the minimum quantity of supply air at 5m3/s. As a result, the only variable open to Waterman’s in developing the auditorium ventilation solution was

to adapt the height and diameter of the four chimneys, to produce a solution capable of maintaining excellent air quality and of dissipating heat gains from the space. Lighting is the biggest heat source within the auditorium. The stage has 140kW of lighting installed, of which approximately 65kW will be on at any one time during a production. Occupants and other heat sources contribute another 50kW of heat. ‘We did a huge amount of modelling work to establish the size, open area, and height needed between the inlet and tops of the chimneys to drive the stack effect to pull air through the auditorium,’ explains Purcell.

 Fortunately for the design team, these early modelling studies showed that the fresh air requirement of 5m3/s would be sufficient to flush the 115kW heat gains from the auditorium. Thermal dynamic simulation modelling was used during the design development to assess conditions inside the auditorium throughout the year. The cooling solution was modelled between the months of May and September to see where the temperature peaks were occurring. ‘Once we found this out, we used computational fluid dynamics (CFD) to model the space at these particular moments in time,’ Purcell says. Thermal mass helps keep the auditorium cool in summer. ‘CFD modelling predicted that we’d get a temperature drop of between 2.5°C and 3.0°C as a result of the thermal mass,’ says Purcell. In addition to the concrete air-intake plenum, 25,000 bricks reclaimed from the old theatre line the auditorium and add significantly to the thermal mass of the space. ‘The only bit of the auditorium enclosure that is lightweight is the roof structure, but we were not too worried by that because – once the air has risen to high level – it is drawn out of the auditorium by the chimneys,’ says Purcell. A night-time cooling strategy helps purge the inlet plenum and auditorium structures of heat in summer. The auditorium modelling also highlighted the problem of insufficient air movement around the upper level gallery seating. ‘When we modelled the air flow, we found that it by- passed the galleries altogether,’ says Purcell. Vomitories (entrances between seating) at the front of the stage, and a corridor beneath the galleries, meant that it was impossible to create a fresh-air path from the plenum beneath the banked seating to the galleries. Instead – in a minor deviation from the natural ventilation strategy – a small, low- speed transfer fan is used to drive air through a ducted system, which links a small plenum beneath the galleries to the large plenum beneath the main auditorium seating. 

 Using detailed modelling demonstrated to Waterman’s that the natural ventilation strategy would be sufficient to keep conditions comfortable in the auditorium throughout the year. The theatre’s trustees, however, were sceptical, and sought the reassurance of additional cooling measures as insurance against the failure of natural ventilation to keep the audience comfortable. As a consequence, two air handling units (AHUs) – complete with direct expansion cooling systems connected to air source heat pumps – are hidden away in the plenum beneath the stage. These have yet to be needed. ‘Last year was the warmest on record, and the theatre operated all year on full natural ventilation, without need to resort to cooling – even during a Saturday matinee,’ says Purcell. An array of actuator-controlled dampers within the basement and high-level auditorium regulates the airflow through the auditorium. In winter, the fresh-air rate is kept to a minimum by carbon dioxide and temperature sensors. ‘When you have the heat load from the audience and from the theatre lighting, the space does not need heating,’ says Purcell. The designers have, however, made clever use of the AHU to preheat the auditorium ahead of shows in winter – reversing the cooling heat pump enables the unit to provide heating without needing to run the boilers. A fully automated control system based on threshold temperatures regulates air flow.

== Backstage ==

In addition to the auditorium, the low energy servicing strategy means that the community room – which doubles as rehearsal space – and the main rehearsal room are also naturally ventilated. The community room ventilation system is similar to that of the main auditorium, with a street-level air intake delivering air to the space through a series of floor grilles, with air exhausted through two, roof-top chimneys. Unlike the main auditorium, however, the room also includes trench heating to pre-heat incoming air during the winter. The main rehearsal room is ventilated using roof-mounted windcatchers to both supply and extract air from the space. The room’s ventilation is supplemented by opening terrace doors to the

Arad Street façade, while radiant panels provide heat to the room. The foyers, too, are naturally ventilated via opening sliding windows in the front façade. The warmed air from these spaces rises up and out of the building through a large lightwell. The only principal space to be mechanically ventilated is the basement bistro (see Figure 2, cross-section of rehearsal spaces and foyer). Solar gains and glare to the foyer and bars are kept to a minimum by the 105 aluminium, life-size-portrait shutters. The shades, which rotate around a central pivot, are positioned by occupants opening a window, manually moving the shade, and then locking it into position. In practice, this means each screen is set at a different angle, at different times of the day, to create a dynamic façade.

== Project Team ==
*Client: Liverpool and Merseyside Theatres Trust
*Architect: Haworth Tompkins
*Services engineer: Waterman Building
*ServicesAcoustic engineer: Gillieron Scott Acoustic Design
*Structural engineer: Alan Baxter Associates
*QS: Gardiner and Theobald
*Theatre consultant: Charcoalblue
*Contractor: Gilbert-Ash

== Costs ==
*Basic building cost: £2,300/m2
*Services cost: £500/m

== BREEAM Data ==

[taken from Haworth Tompkins BREEAM case study]
*Predicted electricity consumption: 86.76KWh/m2
*Predicted fossil fuel consumption: 186.51 KWh/m2
*Predicted energy generation by CHP: 29.18 KWh/m2
*Predicted percentage of WC water use provided by rainwater collection: 45%

== Low Impact Construction ==
*Demolition waste: 90%+ recycled
*Construction waste: 89% recycled

The site’s energy and water use, and the impact of transport to site, were monitored. An on-site biodiversity champion ensured no harm came to established flora and fauna.

Read the full article on the CIBSE website [[www.cibsejournal.com|here]].

CIBSE Case Study: Everyman Theatre Liverpool

2015-02-02T17:01:05Z

CIBSE: Created page with " Article from the February 2015 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Andy Pearson. Four ventilation chimneys named John, Paul, George and..."

Article from the February 2015 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Andy Pearson. 

Four ventilation chimneys named John, Paul, George and Ringo are central to the environmental strategy at the Everyman Theatre in Liverpool, which wowed critics at the Stirling Prize. The judges’ citation for the winner of this year’s RIBA Stirling prize makes clear that Waterman Building Services’ low energy servicing strategy – as much as Haworth Tompkins’ striking architecture – was the reason for their decision to award the best building of the year prize to the Everyman Theatre, in Liverpool. They praised its ‘naturally ventilated auditoria’, applauded the use of concrete labyrinths to ‘supply and expel air’, and described the design as ‘exceptionally sustainable’. The judges’ comments should come as no surprise to the design team; from the outset, sustainability was integral to the concept of the new building . The original Everyman Theatre opened in 1964, converted from the shell of a 19th-century chapel. Over time, however, the fabric of this much-loved institution deteriorated badly, while the increasing needs of its users meant the space was no longer viable. Originally, the plan was to build a larger theatre on a new site, but Haworth Tompkins argued successfully for maintaining an important sense of continuity by reusing the existing, compact, Hope Street site. To accommodate the new building on an area of just 1,610m2 the shell of the existing structure was carefully dismantled to allow most of the chapel’s bricks to be salvaged for use in the theatre’s reincarnation. Haworth Tompkins designed the new Everyman Theatre to derive as much functionality from the building as possible, while incorporating the best-loved features of its predecessor – all within a similar volume. The outcome is that the building’s public spaces – including the foyer and bars – have been arranged in a series of half-level floors, set around the perimeter, to create what the architect describes as ‘a continuous winding promenade, from street to auditorium’. In addition to the main auditorium and the catering spaces, Haworth Tompkins has also managed to slot in numerous creative spaces, including a rehearsal room, workshops, an audio-visual studio, a writers’ room, and a community studio. Externally, the most striking architectural features are the theatre’s main, west-facing elevation, and four, giant, cylindrical chimneys, perched on the roof. The attention-grabbing west façade is formed from 105 movable, aluminium sunshades. These are set in three rows, running the length of the elevation, and each one features a life-size portrait of a contemporary Liverpool resident, cut out of the metal sheet. In contrast, the restrained red brick of the north, east and south elevations help the building sit comfortably with its listed neighbours. That same red brick is also used to form the four giant chimneys, which are a key component of the auditorium’s natural ventilation system. The 400 seat auditorium is at the heart of the 4,690m2 building, literally and metaphorically. It has been designed to accommodate a ‘thrust’ stage (one that extends into the audience), which is encompassed on three sides by seating to recreate the intimacy of the old Everyman Theatre. This familiarity is enhanced by the use of reclaimed bricks from the original theatre, which are exposed in the new auditorium’s walls. As well as giving the auditorium a worn, cosy ambience, the reclaimed bricks add thermal mass to the space, as part of the theatre’s ventilation strategy. ‘The client wanted a very, very sustainable, low energy theatre, so natural ventilation was seen as the obvious solution,’ says Jonathan Purcell, director of building services for Waterman’s, who was charged with developing the ventilation solution for the windowless, artificial environment of the theatre’s auditorium. ‘We had to find a way to ventilate what is essentially a
black box.’ 
== Cooling the stalls ==

The design team’s aim with the auditorium ventilation strategy was, according to Purcell, ‘to provide a nice, clean, swept path for the air to enter the space at low level, then meet very little resistance as it is allowed to rise from low level to high level in the auditorium; and, finally, to provide a simple route out through the roof-top chimneys’. As a result, fresh air enters the building through an inlet louvre on Arad Street, a quiet road at the rear of the building. It then passes through acoustic attenuators and into a giant, concrete-encased plenum, constructed beneath the workshop area behind the theatre’s stage. ‘We’ve got a massive cavern of concrete in contact with the ground, which we use to cool the supply air in summer before it enters the auditorium,’ Purcell explains. From here, the air passes beneath the stage, through secondary attenuators, and into a horseshoe- shaped plenum beneath the banked rows of seating lining the auditorium walls. The fresh air finally enters the auditorium through a series of perforated grilles beneath the seating. Heat given off by the audience, and from the theatre lighting, increases the buoyancy of the air, causing it to rise upwards through the lighting gantries to an acoustically attenuated 2.5m-high exhaust air plenum. A giant duct, which doubles back on itself, then delivers the air from the plenum to the four louvred chimneys – nicknamed John, Paul, George and Ringo by the design team – where it is exhausted. For the system to work effectively, Waterman’s had to generate enough buoyancy to drive a sufficient quantity of air through the auditorium to keep conditions comfortable for the audience. The air inlet size and location was set – its dimensions defined by the street, basement and ground-floor slab levels. Building Regulations requirements for fresh air of 10 litres per second per person for a capacity audience of 450 people, plus 40 staff and actors, set the minimum quantity of supply air at 5m3/s. As a result, the only variable open to Waterman’s in developing the auditorium ventilation solution was

to adapt the height and diameter of the four chimneys, to produce a solution capable of maintaining excellent air quality and of dissipating heat gains from the space. Lighting is the biggest heat source within the auditorium. The stage has 140kW of lighting installed, of which approximately 65kW will be on at any one time during a production. Occupants and other heat sources contribute another 50kW of heat. ‘We did a huge amount of modelling work to establish the size, open area, and height needed between the inlet and tops of the chimneys to drive the stack effect to pull air through the auditorium,’ explains Purcell.

 Fortunately for the design team, these early modelling studies showed that the fresh air requirement of 5m3/s would be sufficient to flush the 115kW heat gains from the auditorium. Thermal dynamic simulation modelling was used during the design development to assess conditions inside the auditorium throughout the year. The cooling solution was modelled between the months of May and September to see where the temperature peaks were occurring. ‘Once we found this out, we used computational fluid dynamics (CFD) to model the space at these particular moments in time,’ Purcell says. Thermal mass helps keep the auditorium cool in summer. ‘CFD modelling predicted that we’d get a temperature drop of between 2.5°C and 3.0°C as a result of the thermal mass,’ says Purcell. In addition to the concrete air-intake plenum, 25,000 bricks reclaimed from the old theatre line the auditorium and add significantly to the thermal mass of the space. ‘The only bit of the auditorium enclosure that is lightweight is the roof structure, but we were not too worried by that because – once the air has risen to high level – it is drawn out of the auditorium by the chimneys,’ says Purcell. A night-time cooling strategy helps purge the inlet plenum and auditorium structures of heat in summer. The auditorium modelling also highlighted the problem of insufficient air movement around the upper level gallery seating. ‘When we modelled the air flow, we found that it by- passed the galleries altogether,’ says Purcell. Vomitories (entrances between seating) at the front of the stage, and a corridor beneath the galleries, meant that it was impossible to create a fresh-air path from the plenum beneath the banked seating to the galleries. Instead – in a minor deviation from the natural ventilation strategy – a small, low- speed transfer fan is used to drive air through a ducted system, which links a small plenum beneath the galleries to the large plenum beneath the main auditorium seating. 

 Using detailed modelling demonstrated to Waterman’s that the natural ventilation strategy would be sufficient to keep conditions comfortable in the auditorium throughout the year. The theatre’s trustees, however, were sceptical, and sought the reassurance of additional cooling measures as insurance against the failure of natural ventilation to keep the audience comfortable. As a consequence, two air handling units (AHUs) – complete with direct expansion cooling systems connected to air source heat pumps – are hidden away in the plenum beneath the stage. These have yet to be needed. ‘Last year was the warmest on record, and the theatre operated all year on full natural ventilation, without need to resort to cooling – even during a Saturday matinee,’ says Purcell. An array of actuator-controlled dampers within the basement and high-level auditorium regulates the airflow through the auditorium. In winter, the fresh-air rate is kept to a minimum by carbon dioxide and temperature sensors. ‘When you have the heat load from the audience and from the theatre lighting, the space does not need heating,’ says Purcell. The designers have, however, made clever use of the AHU to preheat the auditorium ahead of shows in winter – reversing the cooling heat pump enables the unit to provide heating without needing to run the boilers. A fully automated control system based on threshold temperatures regulates air flow.

== Backstage ==

In addition to the auditorium, the low energy servicing strategy means that the community room – which doubles as rehearsal space – and the main rehearsal room are also naturally ventilated. The community room ventilation system is similar to that of the main auditorium, with a street-level air intake delivering air to the space through a series of floor grilles, with air exhausted through two, roof-top chimneys. Unlike the main auditorium, however, the room also includes trench heating to pre-heat incoming air during the winter. The main rehearsal room is ventilated using roof-mounted windcatchers to both supply and extract air from the space. The room’s ventilation is supplemented by opening terrace doors to the

Arad Street façade, while radiant panels provide heat to the room. The foyers, too, are naturally ventilated via opening sliding windows in the front façade. The warmed air from these spaces rises up and out of the building through a large lightwell. The only principal space to be mechanically ventilated is the basement bistro (see Figure 2, cross-section of rehearsal spaces and foyer). Solar gains and glare to the foyer and bars are kept to a minimum by the 105 aluminium, life-size-portrait shutters. The shades, which rotate around a central pivot, are positioned by occupants opening a window, manually moving the shade, and then locking it into position. In practice, this means each screen is set at a different angle, at different times of the day, to create a dynamic façade.

== Project Team ==
*Client: Liverpool and Merseyside Theatres Trust
*Architect: Haworth Tompkins
*Services engineer: Waterman Building
*ServicesAcoustic engineer: Gillieron Scott Acoustic Design
*Structural engineer: Alan Baxter Associates
*QS: Gardiner and Theobald
*Theatre consultant: Charcoalblue
*Contractor: Gilbert-Ash

== Costs ==
*Basic building cost: £2,300/m2
*Services cost: £500/m

== BREEAM Data ==

[taken from Haworth Tompkins BREEAM case study]
*Predicted electricity consumption: 86.76KWh/m2
*Predicted fossil fuel consumption: 186.51 KWh/m2
*Predicted energy generation by CHP: 29.18 KWh/m2
*Predicted percentage of WC water use provided by rainwater collection: 45%

== Low Impact Construction ==
*Demolition waste: 90%+ recycled
*Construction waste: 89% recycled

The site’s energy and water use, and the impact of transport to site, were monitored. An on-site biodiversity champion ensured no harm came to established flora and fauna.

CIBSE Case Study: Walgreens net zero energy drugstore

2015-01-09T15:52:18Z

CIBSE:

Article from the January 2015 edition of the [[Www.cibsejournal.com|CIBSE Journal]] written by Benjamin A Skelton.

Cyclone Energy Group’s Benjamin Skelton explains what happened when the Walgreens drugstore chain set out to build the USA’s first net-zero energy store – in one of the country’s harshest climates. The American pharmacy and grocery chain Walgreens is one of the biggest retail brands in the world, with more than 8,000 stores. So when, five years ago, it decided to build the first net-zero energy store in the US – in a way that would be as scalable as possible to the rest of its estate – the implications were enormous. There were other factors that made the project particularly challenging: Walgreens didn’t want to change the operational nature of the building, so it had to have a conventional interior layout of about 1,350m2, and be open, if not all hours, then at least 50% more than a typical office. Because the company wanted to keep a close eye on the design and construction of the building, it was decided to site it in Evanston, near Chicago – close to its Illinois headquarters. With winter temperatures plunging to -240C, and summers as hot as 350C, it was hardly an auspicious location for a zero-energy building. To be considered net-zero energy, the consumption of the store had to be 41% lower than the area average. The average annual energy consumption for a store in the Chicago area was 435,000kWh, so the building had to be designed to produce 256,000kWh in a typical year. Working with a solar photovoltaic company, Walgreens determined that the proposed building could produce this quantity of electricity using 840 micro-inverter panels on the roof, plus two 5kW vertical wind turbines. Given this fixed production capacity, the question was: how would the designers make sure the building’s consumption was less than 256,000kWh? 

== Fabric and lighting ==

All aspects of the design had to be considered to get the building’s energy consumption below the solar production estimate. The two largest uses of energy in a typical store are lighting and refrigeration, so the Walgreens team carefully analysed the efficiency opportunities in these areas. The fabric design, for example, increased the opportunities for daylighting – although this created further challenges. To maximise solar capacity, the store’s typical rectangular design was changed to a tiered, multilevel, cantilevered roof with clerestory windows. This deviation from the standard brand design included significantly more glass. Moreover, a typical store has ribbon windows and a glass storefront, whereas this building incorporated an entirely curtain-walled west façade. 

 The west-facing fenestration meant that active and passive shading was needed. Glass below 4.3m was treated with automatic shade controls, regulated by an astronomical clock, limiting sun penetration to 1.5m. Direct sunlight was limited to a small distance to prevent cosmetic products from melting. For the glass above 4.3m, a light-redirecting film was installed. Th is sent 90% of the solar light and energy up and into the store, while 10% remained on path. This provided a thermal benefit and prevented glare at the sales counter. The film was applied to a third pane of glass and installed in the framing system of the curtain wall. 

 The wall and roof insulation were standard Walgreens specifi cation, with U values of 0.28W/m2K and 0.19W/m2K respectively. When it came to artifi cial lighting, Walgreens installed its first all-LED system in 2010, and that is what this store received. The sales floor area has eight independent lighting zones with daylight-sensing controls. A typical store design includes 4kW o f under-shelf LED lighting, to provide high levels of illumination on merchandise. This was identified as an opportunity for reducing energy consumption. Special fi xtures chosen for the new store provide a unique light distribution pattern that produce s adequate l uminescence levels, and allows under-shelf lighting to be removed.

== HVAC and refrigeration ==

A standard Walgreens store uses constant volume rooftop units for heating, ventilating and air conditioning (HVAC). As the roof was covered with solar photovoltaic panels, all the equipment had to be internal. A lso, as the store came right to the edge of the site boundary, there was only a very small balcony for air-cooled heat-rejection equipment. With LED lights and daylight controls providing a minimised load, the largest remaining opportunity for energy savings was the refrigeration system. The design team searched for a system that could capture the heat rejection from the refrigeration system and create useful heat. 

 Chicago is a heating-dominated climate – with 6,536 heating degree days – and heating is the largest annual HVAC energy end use. Walgreens had completed a geoexchange store in Chicago previously, and this was considered the best means for capturing the waste heat from refrigeration and using it for HVAC. Eight, 152m vertical geo-exchange wells were designed below the parking lot, and the design team considered several HVAC options, including distributed heat pumps and heat pump rooftop units. Ultimately, a chiller-heater central heat pump system was selected for this store, based on the wholebuilding energy analysis. In addition to net-zero operation, Walgreens had set a secondary goal to create a store that us es only natural refrigerants. With a central heater-chiller heat pump, options existed for a system with a carbon dioxide (CO2) refrigerant. No manufacturers were available in the US, but a couple of options were found in Europe. 

However, the decision to use this system was made only 10 months before the store was due to open. Aware that getting a custombuilt heat pump from Europe posed a risk to the opening schedule, the design team had a US-produced substitute, R-134a-based central heat pump on standby. One requirement of using a CO2 refrigerant heat pump was that the system had to meet Underwriters Laboratories (UL) testing requirements to be permitted for use in the US. UL certification is a common mandatory requirement of insurance companies and code jurisdictions, and requires that refrigerant piping and systems be tested and certified at five times the rated operating pressure. Given the high operating pressure of CO2 (80 to 100 bar), this requirement seemed excessive, but the system passed the tests. It was shipped to the US and made it through customs with no issues. 

 The transcritical CO2 heat pump has three sets of variable speed compressors: low temperature, servicing the evaporators for the freezer ; medium temperature, servicing the evaporators for the cooler ; and high temperature, servicing the chilled water system . The heat rejection for the heat pump is used for hot water and service water. The geo-change serves as a battery, storing heat rejection from the cooler/freezer evaporators for use as heat when needed. With the central systems determined, and a solution found to capture waste heat from the refrigeration system, attention turned to the comfort systems. With low-temperature chilled water and water heating readily available, a four-pipe fan-coil system was designed. Initially, a radiant heat design was included, but this was removed to help meet budget constraints. 

 The sales fl oor area was split into three thermal zones with variable-speed, singlezone, air handling units hanging in the space. Ductwork was designed architecturally as a straight length off the air handling units, with diffusers discharging directly down into the space. The ductwork transferred air to the space effectively, but what wasn’t anticipated was the noise level. At fan speeds above 80%, the air handlers created signifi cant fan noise – more than was acceptable for Walgreens’ operations. So they were limited to 80% maximum speed, which did not have an impact on cooling, but severely hampered the ability to provide heating. A dedicated variable air volume, outside air handling unit was provided to decouple the ventilation load. The unit regulates outside air volume based on demand. The store has a highly variable occupant load and, by using CO2 sensors throughout the sales area, ventilation load is minimised.

== Measured performance ==

Walgreens recognised the opportunity to use this store as a research project. A central building automation system was installed, with remote monitoring and control capabilities. Additionally, a branch breaker, electrical sub-metering system was installed, to measure real-time loads from nearly every piece of equipment in the building. With a detailed measurement and control system, the team was able to monitor hundreds of data points, and fi nd areas where the operation was deviating from the design. After almost a year, the results show that – in the first 12 months – the store will fall short of net-zero energy consumption. There are several reasons for this. Chicago experienced one of the severest winters in record ed history. The design energy model was created using average weather files (typical meteorological year) and included a buffer to account for weather swings. However, with a mean temperature of -8.1°C in January 2014, the extreme cold exhausted most of the buffer. 

 As-built documents detailed that the curtain-wall system underperformed against the design requirements. The installed system exceeded specifi ed fenestration cent re-ofglass performance; however, the framing system was not thermally broken, causing the assembly to under perform at peak conditions by 12%, further exhausting the net-zero buffer. The automated shades served as valuable insulation, and were used at night to help maintain space temperatures. 

With a heat pump design never before attempted on this type of building, it was expected that there would be performance issues. The gas cooler – which was provided to help remove excess heat and prevent the geo-exchange field from becoming overheated in the cooling season – had problems with electrical overloading and was off for most of the first summer. Also, it was determined that the compressors initially provided were oversized. The gas-cooler issue was resolved and the compressors replaced, and energy reductions are being observed.

 Humans cause energy waste. This store is not used by high-tech engineers and, while the system is designed to operate automatically, the employees and customers have an impact on its energy consumption. A revolving door was engineered into the project, replacing an air lock, but it did not have good thermal properties, and was not well sealed. A disabled access door was still required, but this did not have an air lock. Rather, an air curtain was installed to minimise air infiltration when in operation. It was found that a high percentage of nondisabled customers used this door, and the air curtain proved ineffective. Given all of these issues, the path to netzero status is clear. Using the measurement and verification system, and a calibrated energy model, the store is being fine-tuned to reduce energy consumption by 5,000kWh per month. 

 Lessons are still being learned on this project, but the net-zero approach has been recognised with LEED Platinum status, Green Globes certifi cation, and a Green Chill Platinum rating from the US Environmental Protection Agency. Walgreens’ net-zero Chicago store could pave the way for radical changes in the US retail landscape.

Technical Symposium award winner Benjamin Skelton’s paper It’s not easy being green on the design of the Walgreens store was named the ‘Most significant contribution to art and science of building services engineering’at the 2014 Technical Symposium.

== Booking open for 2015 Technical Symposium ==

The 5th CIBSE Technical Symposium will be held on 16 and 17 April 2015 at University College London. The event encourages participation from both young and experienced industry practitioners, researchers and building users to share experiences and develop networks. The 2015 Technical Symposium will address the theme: Simple buildings, better buildings? Delivering performance through engineered solutions. To book your place visit www.cibse.org/symposium

== Ten key lessons ==

Here are the top lessons learned on the project: Don’t rush. The design team had less than one year to do something never done before and that is not enough time to evaluate opportunities. When innovating, don’t forget the fundamentals. Keeping systems as simple as possible will net best results. Require total system thermal performance data on fabric systems. Getting a worse performing curtain-wall system permanently impacts the performance of the store. Engage all contractors early. While contractors knew the net-zero ambition, they were engaged too late in the process to feel any sense of ownership of the greater goal of the project. Many set-up and configuration issues could have been avoided. Commission all building systems as early as possible. Once a building goes into operation and is considered substantially complete, getting contractor support is very difficult. 

Energy meters don’t always tell the correct story. If not for calibrating the design energy model to the store operation, it may never have been noticed that our measurement and verification system was configured incorrectly. Air locks perform better than revolving doors. Customers will go for the easy option, and revolvers require more work than hitting an automatic door-opener button. Geo-exchange couples well with transcritical CO2 refrigerant heat pumps as it provides a steady condensing temperature (<15°C). Technology cannot overcome humans. No matter how well you design an automation system, people can make a mess of it. Don’t start your net-zero performance period in a historically severe weather season!

== Walgreens’ Project Team ==
*Client: Walgreens
*MEP: WMA Consulting Engineers
*Architect: Engineer + Theodore
*Energy consultant: Energy Center of Wisconsin
*Commissioning/ energy consultant: Cyclone Energy Group

You can find the full article on the [http://www.cibsejournal.com/ CIBSE website].

CIBSE Case Study: Walgreens net zero energy drugstore

2015-01-09T15:50:37Z

CIBSE: Created page with " Article from the January 2015 edition of the CIBSE Journal written by Benjamin A Skelton. Cyclone Energy Group’s Benjamin Skelton explains wha..."

Article from the January 2015 edition of the [[www.cibsejournal.com|CIBSE Journal]] written by Benjamin A Skelton. 

Cyclone Energy Group’s Benjamin Skelton explains what happened when the Walgreens drugstore chain set out to build the USA’s first net-zero energy store – in one of the country’s harshest climates. The American pharmacy and grocery chain Walgreens is one of the biggest retail brands in the world, with more than 8,000 stores. So when, five years ago, it decided to build the first net-zero energy store in the US – in a way that would be as scalable as possible to the rest of its estate – the implications were enormous. There were other factors that made the project particularly challenging: Walgreens didn’t want to change the operational nature of the building, so it had to have a conventional interior layout of about 1,350m2, and be open, if not all hours, then at least 50% more than a typical office. Because the company wanted to keep a close eye on the design and construction of the building, it was decided to site it in Evanston, near Chicago – close to its Illinois headquarters. With winter temperatures plunging to -240C, and summers as hot as 350C, it was hardly an auspicious location for a zero-energy building. To be considered net-zero energy, the consumption of the store had to be 41% lower than the area average. The average annual energy consumption for a store in the Chicago area was 435,000kWh, so the building had to be designed to produce 256,000kWh in a typical year. Working with a solar photovoltaic company, Walgreens determined that the proposed building could produce this quantity of electricity using 840 micro-inverter panels on the roof, plus two 5kW vertical wind turbines. Given this fixed production capacity, the question was: how would the designers make sure the building’s consumption was less than 256,000kWh? 

== Fabric and lighting ==

All aspects of the design had to be considered to get the building’s energy consumption below the solar production estimate. The two largest uses of energy in a typical store are lighting and refrigeration, so the Walgreens team carefully analysed the efficiency opportunities in these areas. The fabric design, for example, increased the opportunities for daylighting – although this created further challenges. To maximise solar capacity, the store’s typical rectangular design was changed to a tiered, multilevel, cantilevered roof with clerestory windows. This deviation from the standard brand design included significantly more glass. Moreover, a typical store has ribbon windows and a glass storefront, whereas this building incorporated an entirely curtain-walled west façade. 

 The west-facing fenestration meant that active and passive shading was needed. Glass below 4.3m was treated with automatic shade controls, regulated by an astronomical clock, limiting sun penetration to 1.5m. Direct sunlight was limited to a small distance to prevent cosmetic products from melting. For the glass above 4.3m, a light-redirecting film was installed. Th is sent 90% of the solar light and energy up and into the store, while 10% remained on path. This provided a thermal benefit and prevented glare at the sales counter. The film was applied to a third pane of glass and installed in the framing system of the curtain wall. 

 The wall and roof insulation were standard Walgreens specifi cation, with U values of 0.28W/m2K and 0.19W/m2K respectively. When it came to artifi cial lighting, Walgreens installed its first all-LED system in 2010, and that is what this store received. The sales floor area has eight independent lighting zones with daylight-sensing controls. A typical store design includes 4kW o f under-shelf LED lighting, to provide high levels of illumination on merchandise. This was identified as an opportunity for reducing energy consumption. Special fi xtures chosen for the new store provide a unique light distribution pattern that produce s adequate l uminescence levels, and allows under-shelf lighting to be removed.

== HVAC and refrigeration ==

A standard Walgreens store uses constant volume rooftop units for heating, ventilating and air conditioning (HVAC). As the roof was covered with solar photovoltaic panels, all the equipment had to be internal. A lso, as the store came right to the edge of the site boundary, there was only a very small balcony for air-cooled heat-rejection equipment. With LED lights and daylight controls providing a minimised load, the largest remaining opportunity for energy savings was the refrigeration system. The design team searched for a system that could capture the heat rejection from the refrigeration system and create useful heat. 

 Chicago is a heating-dominated climate – with 6,536 heating degree days – and heating is the largest annual HVAC energy end use. Walgreens had completed a geoexchange store in Chicago previously, and this was considered the best means for capturing the waste heat from refrigeration and using it for HVAC. Eight, 152m vertical geo-exchange wells were designed below the parking lot, and the design team considered several HVAC options, including distributed heat pumps and heat pump rooftop units. Ultimately, a chiller-heater central heat pump system was selected for this store, based on the wholebuilding energy analysis. In addition to net-zero operation, Walgreens had set a secondary goal to create a store that us es only natural refrigerants. With a central heater-chiller heat pump, options existed for a system with a carbon dioxide (CO2) refrigerant. No manufacturers were available in the US, but a couple of options were found in Europe. 

However, the decision to use this system was made only 10 months before the store was due to open. Aware that getting a custombuilt heat pump from Europe posed a risk to the opening schedule, the design team had a US-produced substitute, R-134a-based central heat pump on standby. One requirement of using a CO2 refrigerant heat pump was that the system had to meet Underwriters Laboratories (UL) testing requirements to be permitted for use in the US. UL certification is a common mandatory requirement of insurance companies and code jurisdictions, and requires that refrigerant piping and systems be tested and certified at five times the rated operating pressure. Given the high operating pressure of CO2 (80 to 100 bar), this requirement seemed excessive, but the system passed the tests. It was shipped to the US and made it through customs with no issues. 

 The transcritical CO2 heat pump has three sets of variable speed compressors: low temperature, servicing the evaporators for the freezer ; medium temperature, servicing the evaporators for the cooler ; and high temperature, servicing the chilled water system . The heat rejection for the heat pump is used for hot water and service water. The geo-change serves as a battery, storing heat rejection from the cooler/freezer evaporators for use as heat when needed. With the central systems determined, and a solution found to capture waste heat from the refrigeration system, attention turned to the comfort systems. With low-temperature chilled water and water heating readily available, a four-pipe fan-coil system was designed. Initially, a radiant heat design was included, but this was removed to help meet budget constraints. 

 The sales fl oor area was split into three thermal zones with variable-speed, singlezone, air handling units hanging in the space. Ductwork was designed architecturally as a straight length off the air handling units, with diffusers discharging directly down into the space. The ductwork transferred air to the space effectively, but what wasn’t anticipated was the noise level. At fan speeds above 80%, the air handlers created signifi cant fan noise – more than was acceptable for Walgreens’ operations. So they were limited to 80% maximum speed, which did not have an impact on cooling, but severely hampered the ability to provide heating. A dedicated variable air volume, outside air handling unit was provided to decouple the ventilation load. The unit regulates outside air volume based on demand. The store has a highly variable occupant load and, by using CO2 sensors throughout the sales area, ventilation load is minimised.

== Measured performance ==

Walgreens recognised the opportunity to use this store as a research project. A central building automation system was installed, with remote monitoring and control capabilities. Additionally, a branch breaker, electrical sub-metering system was installed, to measure real-time loads from nearly every piece of equipment in the building. With a detailed measurement and control system, the team was able to monitor hundreds of data points, and fi nd areas where the operation was deviating from the design. After almost a year, the results show that – in the first 12 months – the store will fall short of net-zero energy consumption. There are several reasons for this. Chicago experienced one of the severest winters in record ed history. The design energy model was created using average weather files (typical meteorological year) and included a buffer to account for weather swings. However, with a mean temperature of -8.1°C in January 2014, the extreme cold exhausted most of the buffer. 

 As-built documents detailed that the curtain-wall system underperformed against the design requirements. The installed system exceeded specifi ed fenestration cent re-ofglass performance; however, the framing system was not thermally broken, causing the assembly to under perform at peak conditions by 12%, further exhausting the net-zero buffer. The automated shades served as valuable insulation, and were used at night to help maintain space temperatures. 

With a heat pump design never before attempted on this type of building, it was expected that there would be performance issues. The gas cooler – which was provided to help remove excess heat and prevent the geo-exchange field from becoming overheated in the cooling season – had problems with electrical overloading and was off for most of the first summer. Also, it was determined that the compressors initially provided were oversized. The gas-cooler issue was resolved and the compressors replaced, and energy reductions are being observed.

 Humans cause energy waste. This store is not used by high-tech engineers and, while the system is designed to operate automatically, the employees and customers have an impact on its energy consumption. A revolving door was engineered into the project, replacing an air lock, but it did not have good thermal properties, and was not well sealed. A disabled access door was still required, but this did not have an air lock. Rather, an air curtain was installed to minimise air infiltration when in operation. It was found that a high percentage of nondisabled customers used this door, and the air curtain proved ineffective. Given all of these issues, the path to netzero status is clear. Using the measurement and verification system, and a calibrated energy model, the store is being fine-tuned to reduce energy consumption by 5,000kWh per month. 

 Lessons are still being learned on this project, but the net-zero approach has been recognised with LEED Platinum status, Green Globes certifi cation, and a Green Chill Platinum rating from the US Environmental Protection Agency. Walgreens’ net-zero Chicago store could pave the way for radical changes in the US retail landscape.

Technical Symposium award winner Benjamin Skelton’s paper It’s not easy being green on the design of the Walgreens store was named the ‘Most significant contribution to art and science of building services engineering’at the 2014 Technical Symposium.

== Booking open for 2015 Technical Symposium ==

The 5th CIBSE Technical Symposium will be held on 16 and 17 April 2015 at University College London. The event encourages participation from both young and experienced industry practitioners, researchers and building users to share experiences and develop networks. The 2015 Technical Symposium will address the theme: Simple buildings, better buildings? Delivering performance through engineered solutions. To book your place visit www.cibse.org/symposium

== Ten key lessons ==

Here are the top lessons learned on the project: Don’t rush. The design team had less than one year to do something never done before and that is not enough time to evaluate opportunities. When innovating, don’t forget the fundamentals. Keeping systems as simple as possible will net best results. Require total system thermal performance data on fabric systems. Getting a worse performing curtain-wall system permanently impacts the performance of the store. Engage all contractors early. While contractors knew the net-zero ambition, they were engaged too late in the process to feel any sense of ownership of the greater goal of the project. Many set-up and configuration issues could have been avoided. Commission all building systems as early as possible. Once a building goes into operation and is considered substantially complete, getting contractor support is very difficult. 

Energy meters don’t always tell the correct story. If not for calibrating the design energy model to the store operation, it may never have been noticed that our measurement and verification system was configured incorrectly. Air locks perform better than revolving doors. Customers will go for the easy option, and revolvers require more work than hitting an automatic door-opener button. Geo-exchange couples well with transcritical CO2 refrigerant heat pumps as it provides a steady condensing temperature (<15°C). Technology cannot overcome humans. No matter how well you design an automation system, people can make a mess of it. Don’t start your net-zero performance period in a historically severe weather season!

== Walgreens’ Project Team ==
*Client: Walgreens
*MEP: WMA Consulting Engineers
*Architect: Engineer + Theodore
*Energy consultant: Energy Center of Wisconsin
*Commissioning/ energy consultant: Cyclone Energy Group

Read the full article on

Demand Logic analysis of building management system at King’s College London

2015-01-06T12:41:22Z

CIBSE:

Article from the December 2014 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Liza Young. 

A new data platform that extracts and analyses information from the existing BMS has made annual savings of almost £400,000 at King’s College London. Liza Young finds out how Demand Logic works. Finding energy-saving opportunities in heating, cooling and ventilation systems of large, complex buildings, can be like searching for a needle in a haystack. However, a new web-based platform that extracts and analyses data from building management systems (BMS) has identified 47 opportunities to save energy at King’s College London – which have, so far, resulted in annual savings of £390,000. The system – developed by online energy efficiency company Demand Logic – uses ‘big data’ techniques continuously to stream and analyse thousands of BMS data points, including control signals, sensors, valve positions, set-points and meters. It stores this information in a cloud database, and uses it to provide a suite of infographics to help find common, but highly wasteful, faults – such as items of plant left in manual control, out-of-hours running, or simultaneous heating and cooling. The primary aim is to find low-hanging fruit by identifying the ‘energy insanities’ that are still happening in commercial buildings. The extracted data has the potential to be used alongside dynamic simulation tools, such as EDSL Tas, and resource management and reporting software, such as Verco’s Carbon Desktop, to verify energy projections – and identify energy-saving opportunities – when designing new buildings. 

== Immediate benefits ==

Tom Randall, development manager at Demand Logic, says: ‘Many buildings – even from new – could be riddled with problems, partly because there are not many people onsite to look under the bonnet of what their BMS is doing. ‘It’s cost-effectively fast-tracking the snagging at the building optimisation phase, which can take two to three years – at the point where it’s most painful to the client, in cost terms.’ 

 By avoiding unnecessary plant operation, the platform can help extend the life of equipment, and support condition-based maintenance. It allows facilities managers (FMs) to monitor equipment and focus maintenance – and to replace problem equipment, rather than playing a ‘big game of roulette’ by arbitrarily replacing working equipment at set intervals. Another application of the system is during commissioning and the defects liability process. It can monitor all building services over extended periods, and ensure witnessing does not take place until services are within performance criteria. It can then monitor performance during defects liability, providing robust evidence for identifying issues and assigning responsibility, while avoiding ‘fi nger pointing’. The platform is aimed at a key group of people in the building – the ‘actors’ – who have access to the plant, and can act on the findings. ‘Onsite FMs are the best-placed professionals to pick up and run with this,’ says Randall.

== Energy insanities at King’s ==

At King’s College, where the pilot project has been running since January 2013, the system has so far unearthed 47 energy-saving opportunities, 38 of which have already been addressed, saving an estimated 2,500 tonnes of carbon per year. The problems at the college, which spends £5m a year on energy, turned out to be diverse. Boilers were rapidly cycling on and off because they had inadequate load , and several conflicting temperature set points had been applied to the same open-plan office, causing heating and cooling in the same space. In a ddition – having uncovered a large chiller running all day in the middle of winter – the system found that a 2kW personal electric heater was fi ghting the centralised cooling plant, kicking in an enormous chiller and central pumping, which kept the cold water circulating. 

 Joe Short, chief executive officer at Demand Logic, says: ‘This discovery was possible because the system monitors each of the many hundreds of ceiling-mounted air conditioning outlets in the building, and it was able to identify the one demanding unusual amounts of cooled water.’ The system is different from a metering approach, however, where the objective is to get a full picture of energy flow. ‘That’s not our end game,’ says Short. ‘What we’re asking is whether energy is being wasted unnecessarily. It is often easier to find and fix an energy wastage than to measure it.’

== Closing the performance gap ==

Funded by Innovate UK – formerly the Technology Strategy Board – the £900,000 project is a huge learning resource. Randall says the generation of performance data – which will be as open as possible – will provide industry, academia and government with a pool of data for further analysis. He adds: ‘We’re streaming about three million data points a day, from lots of buildings, so there’s huge potential to carry out data analytics with our partner, London South Bank University.’

By working with Verco and EDSL Tas, the continuous data stream would also be used to verify – and add accuracy to – building physics models to help close the performance gap. Demand Logic intends to develop methodologies for identifying the energy savings made that are compliant with the international performance measurement and verification protocol – a globally recognised approach to claiming savings achieved. The aim is to include approaches, allowed by the protocol, that use calibrated building physics models.

 Alan Jones, managing director of EDSL Tas, says the system is a continuation of the BIM process. A design model, which has gone through compliance calculation, is changed into an expected operational performance model. A second copy of that model will be taught by the system about what the building is doing, identifying how and why variations occur. The client would know that the compliance energy calculation is different from what they are actually seeing, whether that is because they are using it for twice as long, or running it poorly. ‘These questions could be answered, and we would be able to look at projecting future implications of these discrepancies,’ says Jones.[[Www.cibsejournal.com|www.cibsejournal.com]] 

 Moreover, the system would potentially provide an evidence base for building owners to invest in higher-cost energy efficiency measures. Randall says: ‘If a landlord decides to make a big change to the building system, they would have a calibrated thermal model with which they can get a better insight into the effect it would have.’ This data could then be used in the design of another building with similar characteristics. Dave Worthington, managing director of Verco, says getting to the bottom of the discrepancy between design-stage assumptions and reality is challenging – it could be because of weather effects, occupant behaviour, or changes in the kit that was installed or its parameters. ‘It really is a “big data” challenge, which needs the collaboration of the different brains around the table that we have on this project,’ he says. ‘The performance gap is becoming a hotter and hotter topic. Significant progress has been made in the domestic sector, but the non-domestic sector is more difficult. ‘This gap exists because of a lack of access to credible data that people trust and understand, and can make business decisions on the back of them.’ Verco will look to feed the results back to government so it can ensure its energyrelated targets are on track and it is coming up with evidence-based policies that incentivise the right behaviours in nondomestic buildings.

== An exciting future ==

By applying Demand Logic – and having better access to data – Randall says there is potential for FM companies to take more ownership of their energy management programmes and performance risk . The bigger picture is to optimise operational performance of buildings and help close the performance gap. ‘If we succeed, we should make a profound difference tothe tools that building services engineers have to hand to deliver buildings that actually work,’ says Randall. ‘It gives us a potentially interesting future, where we are looking after our buildings long-term, and getting value into our businesses.’

== Automation ==

Demand Logic extracts trend information from the BMS to interrogate the issues. In-house specialists can sift through potential problems, but the team wants more and more of the abnormality detection to be done automatically. Short says: ‘Even a medium-size offi ce has 20-30,000 elements that could be queried, and – over the years – several groups of engineers would have come and labelled them in a different way. ‘We are developing a simple machine learning technique to explore these text labels, because we’re faced with all of this data in an unknown building, and we’ve got to turn it into something that the owners and managers of that building know is their plant.’ Short says the most powerful thing Demand Logic provides is the simple element of being able to add comments on every query view. ‘It’s a place where you can air your hunches and suspicions about a building, in a free and uncriticised way.‘We’re getting beyond the technology, and learning about what context people are working in, professionally – what incentives are driving them, what culture they are working in, what politics are goingon, and what set-up encourages them to act.

== King’s College London ==
*Carbon saving 2,500 tonnes per year
*Money saving £390,000 per year
*Project start date January 2013
*Major plant items tracked 554
*Data points More than 100,000
*Biggest source of savings Run time of major plant

You can find the full article on the CIBSE Journal website.

Demand Logic analysis of building management system at King’s College London

2015-01-06T12:40:34Z

CIBSE:

Article from the December 2014 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Liza Young. 

A new data platform that extracts and analyses information from the existing BMS has made annual savings of almost £400,000 at King’s College London. Liza Young finds out how Demand Logic works. Finding energy-saving opportunities in heating, cooling and ventilation systems of large, complex buildings, can be like searching for a needle in a haystack. However, a new web-based platform that extracts and analyses data from building management systems (BMS) has identified 47 opportunities to save energy at King’s College London – which have, so far, resulted in annual savings of £390,000. The system – developed by online energy efficiency company Demand Logic – uses ‘big data’ techniques continuously to stream and analyse thousands of BMS data points, including control signals, sensors, valve positions, set-points and meters. It stores this information in a cloud database, and uses it to provide a suite of infographics to help find common, but highly wasteful, faults – such as items of plant left in manual control, out-of-hours running, or simultaneous heating and cooling. The primary aim is to find low-hanging fruit by identifying the ‘energy insanities’ that are still happening in commercial buildings. The extracted data has the potential to be used alongside dynamic simulation tools, such as EDSL Tas, and resource management and reporting software, such as Verco’s Carbon Desktop, to verify energy projections – and identify energy-saving opportunities – when designing new buildings. 

== Immediate benefits ==

Tom Randall, development manager at Demand Logic, says: ‘Many buildings – even from new – could be riddled with problems, partly because there are not many people onsite to look under the bonnet of what their BMS is doing. ‘It’s cost-effectively fast-tracking the snagging at the building optimisation phase, which can take two to three years – at the point where it’s most painful to the client, in cost terms.’ 

 By avoiding unnecessary plant operation, the platform can help extend the life of equipment, and support condition-based maintenance. It allows facilities managers (FMs) to monitor equipment and focus maintenance – and to replace problem equipment, rather than playing a ‘big game of roulette’ by arbitrarily replacing working equipment at set intervals. Another application of the system is during commissioning and the defects liability process. It can monitor all building services over extended periods, and ensure witnessing does not take place until services are within performance criteria. It can then monitor performance during defects liability, providing robust evidence for identifying issues and assigning responsibility, while avoiding ‘fi nger pointing’. The platform is aimed at a key group of people in the building – the ‘actors’ – who have access to the plant, and can act on the findings. ‘Onsite FMs are the best-placed professionals to pick up and run with this,’ says Randall.

== Energy insanities at King’s ==

At King’s College, where the pilot project has been running since January 2013, the system has so far unearthed 47 energy-saving opportunities, 38 of which have already been addressed, saving an estimated 2,500 tonnes of carbon per year. The problems at the college, which spends £5m a year on energy, turned out to be diverse. Boilers were rapidly cycling on and off because they had inadequate load , and several conflicting temperature set points had been applied to the same open-plan office, causing heating and cooling in the same space. In a ddition – having uncovered a large chiller running all day in the middle of winter – the system found that a 2kW personal electric heater was fi ghting the centralised cooling plant, kicking in an enormous chiller and central pumping, which kept the cold water circulating. 

 Joe Short, chief executive officer at Demand Logic, says: ‘This discovery was possible because the system monitors each of the many hundreds of ceiling-mounted air conditioning outlets in the building, and it was able to identify the one demanding unusual amounts of cooled water.’ The system is different from a metering approach, however, where the objective is to get a full picture of energy flow. ‘That’s not our end game,’ says Short. ‘What we’re asking is whether energy is being wasted unnecessarily. It is often easier to find and fix an energy wastage than to measure it.’

== Closing the performance gap ==

Funded by Innovate UK – formerly the Technology Strategy Board – the £900,000 project is a huge learning resource. Randall says the generation of performance data – which will be as open as possible – will provide industry, academia and government with a pool of data for further analysis. He adds: ‘We’re streaming about three million data points a day, from lots of buildings, so there’s huge potential to carry out data analytics with our partner, London South Bank University.’

By working with Verco and EDSL Tas, the continuous data stream would also be used to verify – and add accuracy to – building physics models to help close the performance gap. Demand Logic intends to develop methodologies for identifying the energy savings made that are compliant with the international performance measurement and verification protocol – a globally recognised approach to claiming savings achieved. The aim is to include approaches, allowed by the protocol, that use calibrated building physics models.

 Alan Jones, managing director of EDSL Tas, says the system is a continuation of the BIM process. A design model, which has gone through compliance calculation, is changed into an expected operational performance model. A second copy of that model will be taught by the system about what the building is doing, identifying how and why variations occur. The client would know that the compliance energy calculation is different from what they are actually seeing, whether that is because they are using it for twice as long, or running it poorly. ‘These questions could be answered, and we would be able to look at projecting future implications of these discrepancies,’ says Jones.[[www.cibsejournal.com|www.cibsejournal.com]] 

 Moreover, the system would potentially provide an evidence base for building owners to invest in higher-cost energy efficiency measures. Randall says: ‘If a landlord decides to make a big change to the building system, they would have a calibrated thermal model with which they can get a better insight into the effect it would have.’ This data could then be used in the design of another building with similar characteristics. Dave Worthington, managing director of Verco, says getting to the bottom of the discrepancy between design-stage assumptions and reality is challenging – it could be because of weather effects, occupant behaviour, or changes in the kit that was installed or its parameters. ‘It really is a “big data” challenge, which needs the collaboration of the different brains around the table that we have on this project,’ he says. ‘The performance gap is becoming a hotter and hotter topic. Significant progress has been made in the domestic sector, but the non-domestic sector is more difficult. ‘This gap exists because of a lack of access to credible data that people trust and understand, and can make business decisions on the back of them.’ Verco will look to feed the results back to government so it can ensure its energyrelated targets are on track and it is coming up with evidence-based policies that incentivise the right behaviours in nondomestic buildings.

== An exciting future ==

By applying Demand Logic – and having better access to data – Randall says there is potential for FM companies to take more ownership of their energy management programmes and performance risk . The bigger picture is to optimise operational performance of buildings and help close the performance gap. ‘If we succeed, we should make a profound difference tothe tools that building services engineers have to hand to deliver buildings that actually work,’ says Randall. ‘It gives us a potentially interesting future, where we are looking after our buildings long-term, and getting value into our businesses.’

== Automation ==

Demand Logic extracts trend information from the BMS to interrogate the issues. In-house specialists can sift through potential problems, but the team wants more and more of the abnormality detection to be done automatically. Short says: ‘Even a medium-size offi ce has 20-30,000 elements that could be queried, and – over the years – several groups of engineers would have come and labelled them in a different way. ‘We are developing a simple machine learning technique to explore these text labels, because we’re faced with all of this data in an unknown building, and we’ve got to turn it into something that the owners and managers of that building know is their plant.’ Short says the most powerful thing Demand Logic provides is the simple element of being able to add comments on every query view. ‘It’s a place where you can air your hunches and suspicions about a building, in a free and uncriticised way.‘We’re getting beyond the technology, and learning about what context people are working in, professionally – what incentives are driving them, what culture they are working in, what politics are goingon, and what set-up encourages them to act.

== King’s College London ==
*Carbon saving 2,500 tonnes per year
*Money saving £390,000 per year
*Project start date January 2013
*Major plant items tracked 554
*Data points More than 100,000
*Biggest source of savings Run time of major plant

You can find the full article on the CIBSE website.

Demand Logic analysis of building management system at King’s College London

2015-01-06T12:37:30Z

CIBSE:

''Article from the December 2014 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Liza Young.'' 

A new data platform that extracts and analyses information from the existing BMS has made annual savings of almost £400,000 at King’s College London. Liza Young finds out how Demand Logic works. Finding energy-saving opportunities in heating, cooling and ventilation systems of large, complex buildings, can be like searching for a needle in a haystack. However, a new web-based platform that extracts and analyses data from building management systems (BMS) has identified 47 opportunities to save energy at King’s College London – which have, so far, resulted in annual savings of £390,000. The system – developed by online energy efficiency company Demand Logic – uses ‘big data’ techniques continuously to stream and analyse thousands of BMS data points, including control signals, sensors, valve positions, set-points and meters. It stores this information in a cloud database, and uses it to provide a suite of infographics to help find common, but highly wasteful, faults – such as items of plant left in manual control, out-of-hours running, or simultaneous heating and cooling. The primary aim is to find low-hanging fruit by identifying the ‘energy insanities’ that are still happening in commercial buildings. The extracted data has the potential to be used alongside dynamic simulation tools, such as EDSL Tas, and resource management and reporting software, such as Verco’s Carbon Desktop, to verify energy projections – and identify energy-saving opportunities – when designing new buildings. 

== Immediate benefits ==

Tom Randall, development manager at Demand Logic, says: ‘Many buildings – even from new – could be riddled with problems, partly because there are not many people onsite to look under the bonnet of what their BMS is doing. ‘It’s cost-effectively fast-tracking the snagging at the building optimisation phase, which can take two to three years – at the point where it’s most painful to the client, in cost terms.’ 

 By avoiding unnecessary plant operation, the platform can help extend the life of equipment, and support condition-based maintenance. It allows facilities managers (FMs) to monitor equipment and focus maintenance – and to replace problem equipment, rather than playing a ‘big game of roulette’ by arbitrarily replacing working equipment at set intervals. Another application of the system is during commissioning and the defects liability process. It can monitor all building services over extended periods, and ensure witnessing does not take place until services are within performance criteria. It can then monitor performance during defects liability, providing robust evidence for identifying issues and assigning responsibility, while avoiding ‘fi nger pointing’. The platform is aimed at a key group of people in the building – the ‘actors’ – who have access to the plant, and can act on the findings. ‘Onsite FMs are the best-placed professionals to pick up and run with this,’ says Randall.

== Energy insanities at King’s ==

At King’s College, where the pilot project has been running since January 2013, the system has so far unearthed 47 energy-saving opportunities, 38 of which have already been addressed, saving an estimated 2,500 tonnes of carbon per year. The problems at the college, which spends £5m a year on energy, turned out to be diverse. Boilers were rapidly cycling on and off because they had inadequate load , and several conflicting temperature set points had been applied to the same open-plan office, causing heating and cooling in the same space. In a ddition – having uncovered a large chiller running all day in the middle of winter – the system found that a 2kW personal electric heater was fi ghting the centralised cooling plant, kicking in an enormous chiller and central pumping, which kept the cold water circulating. 

 Joe Short, chief executive officer at Demand Logic, says: ‘This discovery was possible because the system monitors each of the many hundreds of ceiling-mounted air conditioning outlets in the building, and it was able to identify the one demanding unusual amounts of cooled water.’ The system is different from a metering approach, however, where the objective is to get a full picture of energy flow. ‘That’s not our end game,’ says Short. ‘What we’re asking is whether energy is being wasted unnecessarily. It is often easier to find and fix an energy wastage than to measure it.’

== Closing the performance gap ==

Funded by Innovate UK – formerly the Technology Strategy Board – the £900,000 project is a huge learning resource. Randall says the generation of performance data – which will be as open as possible – will provide industry, academia and government with a pool of data for further analysis. He adds: ‘We’re streaming about three million data points a day, from lots of buildings, so there’s huge potential to carry out data analytics with our partner, London South Bank University.’

By working with Verco and EDSL Tas, the continuous data stream would also be used to verify – and add accuracy to – building physics models to help close the performance gap. Demand Logic intends to develop methodologies for identifying the energy savings made that are compliant with the international performance measurement and verification protocol – a globally recognised approach to claiming savings achieved. The aim is to include approaches, allowed by the protocol, that use calibrated building physics models.

 Alan Jones, managing director of EDSL Tas, says the system is a continuation of the BIM process. A design model, which has gone through compliance calculation, is changed into an expected operational performance model. A second copy of that model will be taught by the system about what the building is doing, identifying how and why variations occur. The client would know that the compliance energy calculation is different from what they are actually seeing, whether that is because they are using it for twice as long, or running it poorly. ‘These questions could be answered, and we would be able to look at projecting future implications of these discrepancies,’ says Jones. 

 Moreover, the system would potentially provide an evidence base for building owners to invest in higher-cost energy efficiency measures. Randall says: ‘If a landlord decides to make a big change to the building system, they would have a calibrated thermal model with which they can get a better insight into the effect it would have.’ This data could then be used in the design of another building with similar characteristics. Dave Worthington, managing director of Verco, says getting to the bottom of the discrepancy between design-stage assumptions and reality is challenging – it could be because of weather effects, occupant behaviour, or changes in the kit that was installed or its parameters. ‘It really is a “big data” challenge, which needs the collaboration of the different brains around the table that we have on this project,’ he says. ‘The performance gap is becoming a hotter and hotter topic. Significant progress has been made in the domestic sector, but the non-domestic sector is more difficult. ‘This gap exists because of a lack of access to credible data that people trust and understand, and can make business decisions on the back of them.’ Verco will look to feed the results back to government so it can ensure its energyrelated targets are on track and it is coming up with evidence-based policies that incentivise the right behaviours in nondomestic buildings.

== An exciting future ==

By applying Demand Logic – and having better access to data – Randall says there is potential for FM companies to take more ownership of their energy management programmes and performance risk . The bigger picture is to optimise operational performance of buildings and help close the performance gap. ‘If we succeed, we should make a profound difference tothe tools that building services engineers have to hand to deliver buildings that actually work,’ says Randall. ‘It gives us a potentially interesting future, where we are looking after our buildings long-term, and getting value into our businesses.’

== Automation ==

Demand Logic extracts trend information from the BMS to interrogate the issues. In-house specialists can sift through potential problems, but the team wants more and more of the abnormality detection to be done automatically. Short says: ‘Even a medium-size offi ce has 20-30,000 elements that could be queried, and – over the years – several groups of engineers would have come and labelled them in a different way. ‘We are developing a simple machine learning technique to explore these text labels, because we’re faced with all of this data in an unknown building, and we’ve got to turn it into something that the owners and managers of that building know is their plant.’ Short says the most powerful thing Demand Logic provides is the simple element of being able to add comments on every query view. ‘It’s a place where you can air your hunches and suspicions about a building, in a free and uncriticised way.‘We’re getting beyond the technology, and learning about what context people are working in, professionally – what incentives are driving them, what culture they are working in, what politics are goingon, and what set-up encourages them to act.

== King’s College London ==
*Carbon saving 2,500 tonnes per year
*Money saving £390,000 per year
*Project start date January 2013
*Major plant items tracked 554
*Data points More than 100,000
*Biggest source of savings Run time of major plant

Demand Logic analysis of building management system at King’s College London

2015-01-06T12:36:41Z

CIBSE: Created page with " ''Article from the December 2014 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Liza Young.'' A new data platform that extracts and analyses inform..."

''Article from the December 2014 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Liza Young.'' 

A new data platform that extracts and analyses information from the existing BMS has made annual savings of almost £400,000 at King’s College London. Liza Young finds out how Demand Logic works. Finding energy-saving opportunities in heating, cooling and ventilation systems of large, complex buildings, can be like searching for a needle in a haystack. However, a new web-based platform that extracts and analyses data from building management systems (BMS) has identified 47 opportunities to save energy at King’s College London – which have, so far, resulted in annual savings of £390,000. The system – developed by online energy efficiency company Demand Logic – uses ‘big data’ techniques continuously to stream and analyse thousands of BMS data points, including control signals, sensors, valve positions, set-points and meters. It stores this information in a cloud database, and uses it to provide a suite of infographics to help find common, but highly wasteful, faults – such as items of plant left in manual control, out-of-hours running, or simultaneous heating and cooling. The primary aim is to find low-hanging fruit by identifying the ‘energy insanities’ that are still happening in commercial buildings. The extracted data has the potential to be used alongside dynamic simulation tools, such as EDSL Tas, and resource management and reporting software, such as Verco’s Carbon Desktop, to verify energy projections – and identify energy-saving opportunities – when designing new buildings. 

== Immediate benefits ==

Tom Randall, development manager at Demand Logic, says: ‘Many buildings – even from new – could be riddled with problems, partly because there are not many people onsite to look under the bonnet of what their BMS is doing. ‘It’s cost-effectively fast-tracking the snagging at the building optimisation phase, which can take two to three years – at the point where it’s most painful to the client, in cost terms.’ 

 By avoiding unnecessary plant operation, the platform can help extend the life of equipment, and support condition-based maintenance. It allows facilities managers (FMs) to monitor equipment and focus maintenance – and to replace problem equipment, rather than playing a ‘big game of roulette’ by arbitrarily replacing working equipment at set intervals. Another application of the system is during commissioning and the defects liability process. It can monitor all building services over extended periods, and ensure witnessing does not take place until services are within performance criteria. It can then monitor performance during defects liability, providing robust evidence for identifying issues and assigning responsibility, while avoiding ‘fi nger pointing’. The platform is aimed at a key group of people in the building – the ‘actors’ – who have access to the plant, and can act on the findings. ‘Onsite FMs are the best-placed professionals to pick up and run with this,’ says Randall.

== Energy insanities at King’s ==

At King’s College, where the pilot project has been running since January 2013, the system has so far unearthed 47 energy-saving opportunities, 38 of which have already been addressed, saving an estimated 2,500 tonnes of carbon per year. The problems at the college, which spends £5m a year on energy, turned out to be diverse. Boilers were rapidly cycling on and off because they had inadequate load , and several conflicting temperature set points had been applied to the same open-plan office, causing heating and cooling in the same space. In a ddition – having uncovered a large chiller running all day in the middle of winter – the system found that a 2kW personal electric heater was fi ghting the centralised cooling plant, kicking in an enormous chiller and central pumping, which kept the cold water circulating. 

 Joe Short, chief executive officer at Demand Logic, says: ‘This discovery was possible because the system monitors each of the many hundreds of ceiling-mounted air conditioning outlets in the building, and it was able to identify the one demanding unusual amounts of cooled water.’ The system is different from a metering approach, however, where the objective is to get a full picture of energy flow. ‘That’s not our end game,’ says Short. ‘What we’re asking is whether energy is being wasted unnecessarily. It is often easier to find and fix an energy wastage than to measure it.’

== Closing the performance gap ==

Funded by Innovate UK – formerly the Technology Strategy Board – the £900,000 project is a huge learning resource. Randall says the generation of performance data – which will be as open as possible – will provide industry, academia and government with a pool of data for further analysis. He adds: ‘We’re streaming about three million data points a day, from lots of buildings, so there’s huge potential to carry out data

analytics with our partner, London South Bank University.’

By working with Verco and EDSL Tas, the continuous data stream would also be used to verify – and add accuracy to – building physics models to help close the performance gap. Demand Logic intends to develop methodologies for identifying the energy savings made that are compliant with the international performance measurement and verification protocol – a globally recognised approach to claiming savings achieved. The aim is to include approaches, allowed by the protocol, that use calibrated building physics models.

 Alan Jones, managing director of EDSL Tas, says the system is a continuation of the BIM process. A design model, which has gone through compliance calculation, is changed into an expected operational performance model. A second copy of that model will be taught by the system about what the building is doing, identifying how and why variations occur. The client would know that the compliance energy calculation is different from what they are actually seeing, whether that is because they are using it for twice as long, or running it poorly. ‘These questions could be answered, and we would be able to look at projecting future implications of these discrepancies,’ says Jones. 

 Moreover, the system would potentially provide an evidence base for building owners to invest in higher-cost energy efficiency measures. Randall says: ‘If a landlord decides to make a big change to the building system, they would have a calibrated thermal model with which they can get a better insight into the effect it would have.’ This data could then be used in the design of another building with similar characteristics. Dave Worthington, managing director of Verco, says getting to the bottom of the discrepancy between design-stage assumptions and reality is challenging – it could be because of weather effects, occupant behaviour, or changes in the kit that was installed or its parameters. ‘It really is a “big data” challenge, which needs the collaboration of the different brains around the table that we have on this project,’ he says. ‘The performance gap is becoming a hotter and hotter topic. Significant progress has been made in the domestic sector, but the non-domestic sector is more difficult. ‘This gap exists because of a lack of access to credible data that people trust and understand, and can make business decisions on the back of them.’ Verco will look to feed the results back to government so it can ensure its energyrelated targets are on track and it is coming up with evidence-based policies that incentivise the right behaviours in nondomestic buildings.

== An exciting future ==

By applying Demand Logic – and having better access to data – Randall says there is potential for FM companies to take more ownership of their energy management programmes and performance risk . The bigger picture is to optimise operational performance of buildings and help close the performance gap. ‘If we succeed, we should make a profound difference tothe tools that building services engineers have to hand to deliver buildings that actually work,’ says Randall. ‘It gives us a potentially interesting future, where we are looking after our buildings long-term, and getting value into our businesses.’

== Automation ==

Demand Logic extracts trend information from the BMS to interrogate the issues. In-house specialists can sift through potential problems, but the team wants more and more of the abnormality detection to be done automatically. Short says: ‘Even a medium-size offi ce has 20-30,000 elements that could be queried, and – over the years – several groups of engineers would have come and labelled them in a different way. ‘We are developing a simple machine learning technique to explore these text labels, because we’re faced with all of this data in an unknown building, and we’ve got to turn it into something that the owners and managers of that building know is their plant.’ Short says the most powerful thing Demand Logic provides is the simple element of being able to add comments on every query view. ‘It’s a place where you can air your hunches and suspicions about a building, in a free and uncriticised way.‘We’re getting beyond the technology, and learning about what context people are working in, professionally – what incentives are driving them, what culture they are working in, what politics are goingon, and what set-up encourages them to act.

== King’s College London ==
*Carbon saving 2,500 tonnes per year
*Money saving £390,000 per year
*Project start date January 2013
*Major plant items tracked 554
*Data points More than 100,000
*Biggest source of savings Run time of major plant

CIBSE Case Study Derby Council House

2014-11-28T17:01:54Z

CIBSE:

Article from the December 2014 edition of the [http://www.cibsejournal.com/ CIBSE Journal] by Tim Findlay and Olly Paish.

The power of the River Derwent will help to generate 1.1 million kWh of energy as part of the refurbishment of Derby’s 1940s council headquarters. Tim Findlay, of Hoare Lea, and Olly Paish, of Derwent Hydro, explain. The River Derwent has long been a source of energy; it was the force behind the first water-powered cotton mill – at Cromford, in Derbyshire – which gave birth to the Industrial Revolution. Now, nearly 250 years later, Derby City Council boasts its very own hydro-electric power plant, having refurbished its 1940s Council House. The success of the project depended on overcoming a number of technical, legal and financial issues. However, the result is a building that produces enough carbonneutral electricity to gain a –25 and A+ Energy Performance Certificate, as well as a BREEAM Excellent rating. Here’s how it was achieved. 

== Planning process ==

The redevelopment of Council House involved the demolition of a 1970s extension, within what was the central courtyard. This was then in-filled, and a new floor built at roof level, increasing the floor area from 5,600m2 to 18,637m2, enabling all city centre council staff to be located on one site. The refurbishment featured a host of 

sustainable features (see box ‘The route to BREEAM Excellence’). Although the hydropower project at the adjacent Longbridge weir did not start at the same time, it became clear – from an early stage – that the two projects should be linked. This was not only because of their proximity, but also because of the significant value of feeding the generated power directly into a council-owned building. 

 However, the hydropower project took much longer than expected. Despite consultant Derwent Hydro conducting the feasibility study in 2006 – and the council cabinet granting approval in 2007 – the generator only became operational in March 2013. Over the course of several years, £150,000 of the project’s £2m cost was spent on fees to get it through planning, largely because of negotiations with the Environment Agency (EA) – over the licence to transfer water from the river – which took until October 2009. Part of the problem was the lack of coordination of the various EA departments (permitting, fisheries, flood defence and ecology), so communication was required with all parties – simultaneously – to make progress. This delayed the project for almost six months. Satisfying the EA’s flood-defence team was the most challenging aspect of the negotiations. It was only achieved after the council employed Black & Veatch to carry out an open-channel, hydraulic flow modelling exercise, to assess the proposed building’s probable impact on river levels – both up and downstream – during a flood. The EA required the model to use a flow rate corresponding to that caused by a one-in-100-year flood, plus a further 20%. The model showed that the presence of the hydro building had a minimal effect upon the flood levels, and that only 2m3/s from the 400m3/s flood flow actually crossed the site behind the building. At the same time as planning approval was being sought, an unexpected legal issue arose. After the Feed-in Tariff (FIT) was launched, the business case for the hydropower plant incorporated payments available under this scheme for exporting power back to the National Grid. However, at a Local Government Association (LGA) workshop in 2009, it became clear that the Local Government (Miscellaneous Provisions) Act 1976 forbade councils from selling power generated by renewable means, unless it was generated 

in association with heat. Unless the law was changed, Derby council

would have to give away or ‘burn off’ all surplus generation. While the value of exported power was only about 8% of the business case, it was, nonetheless, a part that the council did not want to lose. It worked with law firm Eversheds and the New Local Government Network to lobby the government to change the legislation. The campaign was successful and, in August 2010, the law was revised to allow councils to sell electricity generated from renewable sources, such as wind and hydropower.

== Technical matters ==

Run-of-river hydropower generally requires turbines that can operate on low-water heads.Archimedean screw and Kaplan propeller turbines are both able to work in such conditions, with screw turbines suited to flow rates of up to about 6m3/s. Kaplans become the more economical option from around 3m3/s. The turbine selected at Longbridge weir was a two-metre-diameter, double-regulated vertical Kaplan type, operating in a syphon chamber (see ‘Turbine Design’ box). It has a design flow of 13m3/s, falling to a minimum of 2m3/s, and the design output is 230kW, dropping to a minimum of about 40kW. To establish the turbine design, it was important to understand the considerable variation in the river’s flow rate across the year (see Figure 1). While the peak flow briefly exceeded 100m3/s, the average was 18m3/s, and the minimum 5m3/s. There are abstraction points downstream from Longbridge weir, so the flow within the Derwent to these points is artificially maintained at or above 4m3/s by releases from reservoirs. This means hydropower schemes along the river will always have some water from which to generate power. The red line in Figure 1 represents the typical flow over the weir with the turbine operating, while the area between the two lines represents the total energy available to be captured and converted to electricity. The graph in Figure 2 translates the fluctuating river flows into a simpler format, showing the percentage of a year that any given flow rate is exceeded. It also shows how the head across the weir drops with increasing river flow. The two characteristics have been combined to form the anticipated turbine flow line. This shows it tracks the river flow – from a minimum turbine flow of 2m3/s, at a head approaching 2.8m; up to a practical design maximum of 13m3/s, at about 2.5m head; and back to zero when the head, in flood conditions, drops below 1m. The area under the green line represents the available energy captured by the hydro. The original annual output forecast for the plant was 1.25 million kWh, but this had to be reduced to 1.1 million kWh when the EA insisted on a 12.5mm intakescreen gap, as well as a 40mm bar-spacing tailrace screen, both of which increased the parasitic head loss and so reduced the potential output. Total generation from March to the end of November 2013 exceeded 570,000kWh. Given that, during this period, there were the usual teething problems, an enforced two-week shutdown, and unusually low river fl ows, the forecast annual output of 1.1 million kWh does appear to be achievable. 

== Project Team ==
*Building services engineer/architect/client: Derby City Council 
*Project manager/cost consultant: Faithful and Gould 
*Hydro consultant: Derwent Hydro 
*Project continuity: Hoare Lea 
*Main contractor: Balfour Beatty 
*Hydro manufacturer/installer: Hydreo 

== Council House Project Team ==
*� Client: Derby City Council
*� Project manager: Mace
*� Architect: Corstorphine and Wright
*� MEP/BREEAM/Acoustic consultant/fi re engineering: Hoare Lea
*� Main contractor: BAM
*� Building services contractor: Emcor

== The route to BREEAM Excellent ==

The Council House design team followed the usual carbon-reduction process of using less – and using it more efficiently – and employing renewables as much as possible. However, maximising the potential of the River Derwent allowed them to go beyond what many other projects can achieve. Using less involved: reinsulating the roof and walls; replacing windows with high-performance glazing; improving airtightness; adding solar shading; exposing thermal mass, using stack ventilation; and incorporating natural lighting via three atriums. A number of approaches were adopted to use energy and water efficiently. These include 

reduction of mechanical cooling; Turbocor compressors in the chillers; use of adiabatic cooling via the exhaust airstream and heat wheels; energy-efficient comfort cooling from displacement ventilation and ECDC fan-coil units; intelligent lighting – controlled by occupancy sensors – and daylight-linked dimming; power-factor correction; rainwater 

harvesting; and low-water sanitary ware. In addition to hydropower from Longbridge weir, the renewable technologies in the Council House project 

include: solar thermal panels for hot water; solar photovoltaic panels

for additional electricity generation; river water for cooling the fresh supply air; and air source heat pumps. 

== Turbo design ==

The selection of a two-metre-diameter, doubleregulated, vertical, Kaplan syphonic turbine has a number of benefits. It can be started and stopped, easily – using a vacuum pump and air inlet valve – and does not need expensive, slow sluice gates, which are prone to damage and can be difficult to maintain. The double regulation of the turbine also means that the inlet guide vanes and the turbine runner blade pitch are adjustable. The control system modulates both, to hold the turbine speed at 1,000rpm. The gearbox steps up the rotational speed to 2,500rpm for the generator. Once it is started and synchronised to the grid, holding the runner at 1,000rpm maintains the synchronisation. An upstream water-level sensor in the intake canal is used to control the turbine water throughput, to hold a minimum 50mm water depth over the weir crest. This represents a minimum fl ow over the weir of about 2m3/s. The lead time for the turbine was a year, so the order was not placed until all the main permissions were in place, and the scheme viability was assured. There are very few turbine manufacturers in Europe producing turbines of the necessary type and size. The chosen supplier was the French manufacturer Hydreo.

For the full article on the [http://www.designingbuildings.co.uk/wiki/CIBSE CIBSE] website [[www.cibsejournal.com|click here]][http://www.cibse.org/knowledge/case-studies/cibse-case-study-sainsbury-s .]

CIBSE Case Study Derby Council House

2014-11-28T16:58:10Z

CIBSE:

Article from the December 2014 edition of the [http://www.cibsejournal.com/ CIBSE Journal]. 

The power of the River Derwent will help to generate 1.1 million kWh of energy as part of the refurbishment of Derby’s 1940s council headquarters. Tim Findlay, of Hoare Lea, and Olly Paish, of Derwent Hydro, explain. The River Derwent has long been a source of energy; it was the force behind the first water-powered cotton mill – at Cromford, in Derbyshire – which gave birth to the Industrial Revolution. Now, nearly 250 years later, Derby City Council boasts its very own hydro-electric power plant, having refurbished its 1940s Council House. The success of the project depended on overcoming a number of technical, legal and financial issues. However, the result is a building that produces enough carbonneutral electricity to gain a –25 and A+ Energy Performance Certificate, as well as a BREEAM Excellent rating. Here’s how it was achieved. 

== Planning process ==

The redevelopment of Council House involved the demolition of a 1970s extension, within what was the central courtyard. This was then in-filled, and a new floor built at roof level, increasing the floor area from 5,600m2 to 18,637m2, enabling all city centre council staff to be located on one site. The refurbishment featured a host of 

sustainable features (see box ‘The route to BREEAM Excellence’). Although the hydropower project at the adjacent Longbridge weir did not start at the same time, it became clear – from an early stage – that the two projects should be linked. This was not only because of their proximity, but also because of the significant value of feeding the generated power directly into a council-owned building. 

 However, the hydropower project took much longer than expected. Despite consultant Derwent Hydro conducting the feasibility study in 2006 – and the council cabinet granting approval in 2007 – the generator only became operational in March 2013. Over the course of several years, £150,000 of the project’s £2m cost was spent on fees to get it through planning, largely because of negotiations with the Environment Agency (EA) – over the licence to transfer water from the river – which took until October 2009. Part of the problem was the lack of coordination of the various EA departments (permitting, fisheries, flood defence and ecology), so communication was required with all parties – simultaneously – to make progress. This delayed the project for almost six months. Satisfying the EA’s flood-defence team was the most challenging aspect of the negotiations. It was only achieved after the council employed Black & Veatch to carry out an open-channel, hydraulic flow modelling exercise, to assess the proposed building’s probable impact on river levels – both up and downstream – during a flood. The EA required the model to use a flow rate corresponding to that caused by a one-in-100-year flood, plus a further 20%. The model showed that the presence of the hydro building had a minimal effect upon the flood levels, and that only 2m3/s from the 400m3/s flood flow actually crossed the site behind the building. At the same time as planning approval was being sought, an unexpected legal issue arose. After the Feed-in Tariff (FIT) was launched, the business case for the hydropower plant incorporated payments available under this scheme for exporting power back to the National Grid. However, at a Local Government Association (LGA) workshop in 2009, it became clear that the Local Government (Miscellaneous Provisions) Act 1976 forbade councils from selling power generated by renewable means, unless it was generated 

in association with heat. Unless the law was changed, Derby council

would have to give away or ‘burn off’ all surplus generation. While the value of exported power was only about 8% of the business case, it was, nonetheless, a part that the council did not want to lose. It worked with law firm Eversheds and the New Local Government Network to lobby the government to change the legislation. The campaign was successful and, in August 2010, the law was revised to allow councils to sell electricity generated from renewable sources, such as wind and hydropower.

== Technical matters ==

Run-of-river hydropower generally requires turbines that can operate on low-water heads.Archimedean screw and Kaplan propeller turbines are both able to work in such conditions, with screw turbines suited to flow rates of up to about 6m3/s. Kaplans become the more economical option from around 3m3/s. The turbine selected at Longbridge weir was a two-metre-diameter, double-regulated vertical Kaplan type, operating in a syphon chamber (see ‘Turbine Design’ box). It has a design flow of 13m3/s, falling to a minimum of 2m3/s, and the design output is 230kW, dropping to a minimum of about 40kW. To establish the turbine design, it was important to understand the considerable variation in the river’s flow rate across the year (see Figure 1). While the peak flow briefly exceeded 100m3/s, the average was 18m3/s, and the minimum 5m3/s. There are abstraction points downstream from Longbridge weir, so the flow within the Derwent to these points is artificially maintained at or above 4m3/s by releases from reservoirs. This means hydropower schemes along the river will always have some water from which to generate power. The red line in Figure 1 represents the typical flow over the weir with the turbine operating, while the area between the two lines represents the total energy available to be captured and converted to electricity. The graph in Figure 2 translates the fluctuating river flows into a simpler format, showing the percentage of a year that any given flow rate is exceeded. It also shows how the head across the weir drops with increasing river flow. The two characteristics have been combined to form the anticipated turbine flow line. This shows it tracks the river flow – from a minimum turbine flow of 2m3/s, at a head approaching 2.8m; up to a practical design maximum of 13m3/s, at about 2.5m head; and back to zero when the head, in flood conditions, drops below 1m. The area under the green line represents the available energy captured by the hydro. The original annual output forecast for the plant was 1.25 million kWh, but this had to be reduced to 1.1 million kWh when the EA insisted on a 12.5mm intakescreen gap, as well as a 40mm bar-spacing tailrace screen, both of which increased the parasitic head loss and so reduced the potential output. Total generation from March to the end of November 2013 exceeded 570,000kWh. Given that, during this period, there were the usual teething problems, an enforced two-week shutdown, and unusually low river fl ows, the forecast annual output of 1.1 million kWh does appear to be achievable. 

== Project Team ==
*Building services engineer/architect/client: Derby City Council 
*Project manager/cost consultant: Faithful and Gould 
*Hydro consultant: Derwent Hydro 
*Project continuity: Hoare Lea 
*Main contractor: Balfour Beatty 
*Hydro manufacturer/installer: Hydreo 

== Council House Project Team ==
*� Client: Derby City Council
*� Project manager: Mace
*� Architect: Corstorphine and Wright
*� MEP/BREEAM/Acoustic consultant/fi re engineering: Hoare Lea
*� Main contractor: BAM
*� Building services contractor: Emcor

== The route to BREEAM Excellent ==

The Council House design team followed the usual carbon-reduction process of using less – and using it more efficiently – and employing renewables as much as possible. However, maximising the potential of the River Derwent allowed them to go beyond what many other projects can achieve. Using less involved: reinsulating the roof and walls; replacing windows with high-performance glazing; improving airtightness; adding solar shading; exposing thermal mass, using stack ventilation; and incorporating natural lighting via three atriums. A number of approaches were adopted to use energy and water efficiently. These include 

reduction of mechanical cooling; Turbocor compressors in the chillers; use of adiabatic cooling via the exhaust airstream and heat wheels; energy-efficient comfort cooling from displacement ventilation and ECDC fan-coil units; intelligent lighting – controlled by occupancy sensors – and daylight-linked dimming; power-factor correction; rainwater 

harvesting; and low-water sanitary ware. In addition to hydropower from Longbridge weir, the renewable technologies in the Council House project 

include: solar thermal panels for hot water; solar photovoltaic panels

for additional electricity generation; river water for cooling the fresh supply air; and air source heat pumps. 

== Turbo design ==

The selection of a two-metre-diameter, doubleregulated, vertical, Kaplan syphonic turbine has a number of benefits. It can be started and stopped, easily – using a vacuum pump and air inlet valve – and does not need expensive, slow sluice gates, which are prone to damage and can be difficult to maintain. The double regulation of the turbine also means that the inlet guide vanes and the turbine runner blade pitch are adjustable. The control system modulates both, to hold the turbine speed at 1,000rpm. The gearbox steps up the rotational speed to 2,500rpm for the generator. Once it is started and synchronised to the grid, holding the runner at 1,000rpm maintains the synchronisation. An upstream water-level sensor in the intake canal is used to control the turbine water throughput, to hold a minimum 50mm water depth over the weir crest. This represents a minimum fl ow over the weir of about 2m3/s. The lead time for the turbine was a year, so the order was not placed until all the main permissions were in place, and the scheme viability was assured. There are very few turbine manufacturers in Europe producing turbines of the necessary type and size. The chosen supplier was the French manufacturer Hydreo.

CIBSE Case Study Derby Council House

2014-11-28T16:53:03Z

CIBSE: Created page with " The power of the River Derwent will help to generate 1.1 million kWh of energy as part of the refurbishment of Derby’s 1940s council headquarters. Tim Findlay, of Hoare..."

The power of the River Derwent will help to generate 1.1 million kWh of energy as part of the refurbishment of Derby’s 1940s council headquarters. Tim Findlay, of Hoare Lea, and Olly Paish, of Derwent Hydro, explain. The River Derwent has long been a source of energy; it was the force behind the first water-powered cotton mill – at Cromford, in Derbyshire – which gave birth to the Industrial Revolution. Now, nearly 250 years later, Derby City Council boasts its very own hydro-electric power plant, having refurbished its 1940s Council House. The success of the project depended on overcoming a number of technical, legal and financial issues. However, the result is a building that produces enough carbonneutral electricity to gain a –25 and A+ Energy Performance Certificate, as well as a BREEAM Excellent rating. Here’s how it was achieved. 

== Planning process ==

The redevelopment of Council House involved the demolition of a 1970s extension, within what was the central courtyard. This was then in-filled, and a new floor built at roof level, increasing the floor area from 5,600m2 to 18,637m2, enabling all city centre council staff to be located on one site. The refurbishment featured a host of 

sustainable features (see box ‘The route to BREEAM Excellence’). Although the hydropower project at the adjacent Longbridge weir did not start at the same time, it became clear – from an early stage – that the two projects should be linked. This was not only because of their proximity, but also because of the significant value of feeding the generated power directly into a council-owned building. 

 However, the hydropower project took much longer than expected. Despite consultant Derwent Hydro conducting the feasibility study in 2006 – and the council cabinet granting approval in 2007 – the generator only became operational in March 2013. Over the course of several years, £150,000 of the project’s £2m cost was spent on fees to get it through planning, largely because of negotiations with the Environment Agency (EA) – over the licence to transfer water from the river – which took until October 2009. Part of the problem was the lack of coordination of the various EA departments (permitting, fisheries, flood defence and ecology), so communication was required with all parties – simultaneously – to make progress. This delayed the project for almost six months. Satisfying the EA’s flood-defence team was the most challenging aspect of the negotiations. It was only achieved after the council employed Black & Veatch to carry out an open-channel, hydraulic flow modelling exercise, to assess the proposed building’s probable impact on river levels – both up and downstream – during a flood. The EA required the model to use a flow rate corresponding to that caused by a one-in-100-year flood, plus a further 20%. The model showed that the presence of the hydro building had a minimal effect upon the flood levels, and that only 2m3/s from the 400m3/s flood flow actually crossed the site behind the building. At the same time as planning approval was being sought, an unexpected legal issue arose. After the Feed-in Tariff (FIT) was launched, the business case for the hydropower plant incorporated payments available under this scheme for exporting power back to the National Grid. However, at a Local Government Association (LGA) workshop in 2009, it became clear that the Local Government (Miscellaneous Provisions) Act 1976 forbade councils from selling power generated by renewable means, unless it was generated 

in association with heat. Unless the law was changed, Derby council

would have to give away or ‘burn off’ all surplus generation. While the value of exported power was only about 8% of the business case, it was, nonetheless, a part that the council did not want to lose. It worked with law firm Eversheds and the New Local Government Network to lobby the government to change the legislation. The campaign was successful and, in August 2010, the law was revised to allow councils to sell electricity generated from renewable sources, such as wind and
hydropower.
== Technical matters ==

Run-of-river hydropower generally requires turbines that can operate on low-water heads.Archimedean screw and Kaplan propeller turbines are both able to work in such conditions, with screw turbines suited to flow rates of up to about 6m3/s. Kaplans become the more economical option from around 3m3/s. The turbine selected at Longbridge weir was a two-metre-diameter, double-regulated vertical Kaplan type, operating in a syphon chamber (see ‘Turbine Design’ box). It has a design flow of 13m3/s, falling to a minimum of 2m3/s, and the design output is 230kW, dropping to a minimum of about 40kW. To establish the turbine design, it was important to understand the considerable variation in the river’s flow rate across the year (see Figure 1). While the peak flow briefly exceeded 100m3/s, the average was 18m3/s, and the minimum 5m3/s. There are abstraction points downstream from Longbridge weir, so the flow within the Derwent to these points is artificially maintained at or above 4m3/s by releases from reservoirs. This means hydropower schemes along the river will always have some water from which to generate power. The red line in Figure 1 represents the typical flow over the weir with the turbine operating, while the area between the two lines represents the total energy available to be captured and converted to electricity. The graph in Figure 2 translates the fluctuating river flows into a simpler format, showing the percentage of a year that any given flow rate is exceeded. It also shows how the head across the weir drops with increasing river flow. The two characteristics have been combined to form the anticipated turbine flow line. This shows it tracks the river flow – from a minimum turbine flow of 2m3/s, at a head approaching 2.8m; up to a practical design maximum of 13m3/s, at about 2.5m head; and back to zero when the head, in flood conditions, drops below 1m. The area under the green line represents the available energy captured by the hydro. The original annual output forecast for the plant was 1.25 million kWh, but this had to be reduced to 1.1 million kWh when the EA insisted on a 12.5mm intakescreen gap, as well as a 40mm bar-spacing tailrace screen, both of which increased the parasitic head loss and so reduced the potential output. Total generation from March to the end of November 2013 exceeded 570,000kWh. Given that, during this period, there were the usual teething problems, an enforced two-week shutdown, and unusually low river fl ows, the forecast annual output of 1.1 million kWh does appear to be achievable. 

== Project Team ==
* Building services engineer/architect/client: Derby City Council 
* Project manager/cost consultant: Faithful and Gould 
* Hydro consultant: Derwent Hydro 
* Project continuity: Hoare Lea 
* Main contractor: Balfour Beatty 
* Hydro manufacturer/installer: Hydreo 

== Council House Project Team ==
*� Client: Derby City Council
*� Project manager: Mace
*� Architect: Corstorphine and Wright
*� MEP/BREEAM/Acoustic consultant/fi re engineering: Hoare Lea
*� Main contractor: BAM
*� Building services contractor: Emcor

== The route to BREEAM Excellent ==

The Council House design team followed the usual carbon-reduction process of using less – and using it more efficiently – and employing renewables as much as possible. However, maximising the potential of the River Derwent allowed them to go beyond what many other projects can achieve. Using less involved: reinsulating the roof and walls; replacing windows with high-performance glazing; improving airtightness; adding solar shading; exposing thermal mass, using stack ventilation; and incorporating natural lighting via three atriums. A number of approaches were adopted to use energy and water efficiently. These include 

reduction of mechanical cooling; Turbocor compressors in the chillers; use of adiabatic cooling via the exhaust airstream and heat wheels; energy-efficient comfort cooling from displacement ventilation and ECDC fan-coil units; intelligent lighting – controlled by occupancy sensors – and daylight-linked dimming; power-factor correction; rainwater 

harvesting; and low-water sanitary ware. In addition to hydropower from Longbridge weir, the renewable technologies in the Council House project 

include: solar thermal panels for hot water; solar photovoltaic panels

for additional electricity generation; river water for cooling the fresh supply air; and air source heat pumps. 

== Turbo design ==

The selection of a two-metre-diameter, doubleregulated, vertical, Kaplan syphonic turbine has a number of benefits. It can be started and stopped, easily – using a vacuum pump and air inlet valve – and does not need expensive, slow sluice gates, which are prone to damage and can be difficult to maintain. The double regulation of the turbine also means

that the inlet guide vanes and the turbine runner blade pitch are adjustable. The control system modulates both, to hold the turbine speed at 1,000rpm. The gearbox steps up the rotational speed to 2,500rpm for

the generator. Once it is started and synchronised to the grid, holding the runner at 1,000rpm maintains the synchronisation. An upstream water-level sensor in the intake canal is used to control the turbine water throughput, to hold a minimum 50mm water depth over the weir crest. This represents a minimum fl ow over the weir of about 2m3/s. The lead time for the turbine was a year, so the order was not placed until all the main permissions were in place, and the scheme viability was assured. There are very few turbine manufacturers in Europe producing turbines of the necessary type and size. The chosen supplier was the

French manufacturer Hydreo.

Restoration of 50 Martin Place, Sydney

2014-11-21T14:42:48Z

CIBSE:

Article from the November 2014 edition of the CIBSE Journal written by Alex Pettifer.

 
Innovative engineering and careful restoration transformed an Australian Beaux Arts beauty into a global investment bank’s HQ. Arup’s Andrew Pettifer FCIBSE explains how a Sydney belle became hi-tech real estate.

Fifty Martin Place is a historic building in the heart of Sydney’s financial district. Constructed between 1925 and 1928 – for what was then the Government Savings Bank of New South Wales – it is a rare Australian example of the American-influenced, inter-war Beaux Arts style. Macquarie Group, Australia’s only global investment bank, acquired the building in 2012 to create its new corporate headquarters. This was a radical step in the Australian property market where, typically, commercial property is owned and managed by real estate investment trusts. The fact that Macquarie was to be an owner-occupier opened up opportunities both to refurbish an important heritage building, and to create a world-class workspace, specifically designed to meet the bank’s corporate objectives of enhanced performance through connectivity, collaboration and sustainability. Consequently, 50 Martin Place has become the largest historic refurbishment in Australia to be awarded a Six Star Green Star rating – representing ‘ world leadership’ – by the Green Building Council of Australia. The design strategy involved the creation of a glass, domed roof – to house client facilities and meeting rooms – and an enlarged, open-edged atrium. The atrium is the centrepiece of the project, enhancing daylight penetration through the core of the building, while accommodating open stairs that provide connectivity between office floors. The strategy presented Arup, the sustainable design and building services consultant for the project, with a number of challenges. The first was to remove as much plant as possible from the roof to free up space for client use. Plant that remained at roof level – including cooling towers, standby generators and smoke exhaust fans – was carefully integrated into the new glazed structure, to minimise the intrusion into the architectural form. Other plant was sensitively relocated to reduce the impact on the historic fabric of the building. This included the conversion of original water tanks into fan- and boiler- plant rooms, and the relocation of chillers from the roof to the basement. An existing light well was used as a fresh-air intake, and worked in tandem with the atrium, which acted as the exhaust air path. The office air conditioning solution uses passive chilled beams, coupled with fresh air supply delivered through a 250 mm-high raised-access floor. The combination is Australia’s first example of such an approach (see panel, ‘Air conditioning’).
<h2>
Seeing the light</h2>

Given the heritage of 50 Martin Place, its façade has far less glazing than contemporary buildings, and access to daylight and views is well below modern expectations. A key design objective of the project, therefore, was to bring daylight, sky views, and interconnectivity from the top of building to its core. This was achieved through the transparent new roof structure and the enlargement of the existing narrow atrium, to increase daylight penetration into the building, while creating a visual point of connection to the outdoors. Innovative glazing technology – comprising triple glazing with an inbuilt extruded mesh – creates a high-performing fabric. The result is superior thermal comfort, ample daylight, and extensive sky views. Architecturally, the result is a transparent volume, clearly demarcating the new and the old, and respecting the history of the building. Extensive daylight analysis was conducted, to demonstrate to the Heritage Council of NSW the environmental benefits of increasing the atrium size. The analysis quantified the benefits of increasing the atrium width for daylight penetration on the floor plates, and within the atrium. Further studies were conducted to determine the best configuration for the internal stairs interconnecting the atrium to ensure the stairs allowed as much daylight as possible to reach the bottom of the space. The results of the analysis showed daylight reach within the atrium would extend three storeys deeper, compared with the existing building. Useful daylight penetration into the office space was increased by approximately 150%. Modelling was also undertaken to assess sunlight penetration, and an automatic blind system will shade the atrium floor during the relatively few hours in a year when the sun is sufficiently high to penetrate the office space.
<h2>
Lighting</h2>

The office lighting layout was developed to reinforce the structural and ceiling grid in the original building, and to expose the historic fabric previously hidden behind the ceiling. The offices and atrium have perimeter, ceiling-mounted daylight sensors that dim the adjacent lighting when sufficient daylight reaches the work desks. To maximise the effect of the widened atrium, it was decided not to add any further equipment to light the void. Vertical circulation lighting is managed using integrated balustrade lighting in the stair. This also plays on the perforated balustrade panels, giving the stair the appearance of a glowing ribbon rising up through the generous space. At high level, the need to mount luminaires beneath the glazing has been avoided by the design of self-illuminated glass bridges. At the base of the atrium, an indirect mirror system is used to redirect light to the traders. The luminaires and mirrors are mounted to the exposed beams at the perimeter of the void, to provide clear views up through the atrium.
<h2>
Fire Safety Engineering</h2>

While the large open atrium allows daylight to penetrate deep into the building, it did provide the engineers with a tough challenge in terms of fire safety. The Building Code of Australia limits the number of floors that can be connected via openings to two above ground, although any number may be connected via a sealed atrium. The requirements for a sealed atrium are onerous, with glazing and wall-wetting systems, smoke exhaust, emergency power, multiple exit routes for any balconies, and – importantly – no real connection to the floors. This did not meet Macquarie’s desire for the atrium to be open and therefore enhance connectivity and collaboration within the business. To achieve an open-edged atrium – and provide the required interconnectivity – a performance-based, fire-engineering design was developed by Arup’s fire engineers. In the event of fire, the non-fire floors are smoke-separated from the atrium by a combination of drop-down smoke curtains and glazed panels, required to resolve tricky etailing around large heritage beams. The fire floor remains open to the atrium, and large smoke exhaust fans extract from the top of the atrium at a rate of 40 m 3/hr, while make-up air comes from automation of existing heritage balcony doors at level two,combined with the general supply air system. The new client floors constructed within the glass-dome roof extension are open to the atrium. For these floors, exiting through a smoke-proof construction to fire-escape stairs – off an external terrace – enables occupants to move to a place of relative safety before evacuating. This approach allows for high-occupant numbers to be accommodated within the client entertaining areas. Sprinklers are provided throughout the building to keep fire sizes low. Smoke detection – including beam detection in the atrium – provides for early warning, while pressurised escape routes give people time to evacuate the fire floor and those adjacent to it, simultaneously. There is staged evacuation for the remaining floors. Another significant task was to upgrade the numerous styles of heritage luminaires on the original staircases and the halls, some of which were gas mantle luminaires. To upgrade the historic fittings, a number of diffuse LED sources were developed, effectively replicating the optical distribution of older tungsten lamps, while increasing the lumen output to meet the egress requirements.
<h2>
Summary</h2>

50 Martin Place demonstrates how new life can be breathed into a historic building, to create an exciting contemporary workplace. The project highlights that the unique characteristics of such a construction requires highly bespoke engineering solutions. The result, however, is a building that is prudent in the reuse of existing resources, energy efficient in performance, and – most importantly – meets the client’s objectives of creating an inspiring and efficient place to work.
<h2>
Air conditioning</h2>

The general office air-conditioning solution uses passive chilled beams, coupled with dehumidified fresh air supply, delivered through swirl outlets in a 250 mm-high raised-access floor, acting as a plenum. Raised-access flooring systems are not common in the Australian commercial market, and the combination of chilled beams with supply air through the floor at 50 Martin Place is the country’s first example of such an approach. Mindful of the potential leakiness of the heritage structure, the raised floor plenums went through rigorous pressure testing on site, to ensure that performance requirements were met. The swirl outlets were specified to have an adjustable throw pattern of +/-30 degrees from the vertical, to provide occupants with the opportunity to adjust the air distribution in their vicinity.The ceiling-level services have been carefully arranged to complement the original ceiling design, and allow the 1920s structural grid to be exposed. Passive chilled beams enabled the ceiling to be pushed up within the beam structure, resulting in a 270 mm-deep ceiling zone, bordered by a 450 mm-deep structural beam grid. Full factory testing of the beams, acting in combination with the specified floor diffusers, allowed the design to be verified before installation. To avoid the need for long and deep ductwork runs from the side core configuration at each level, supply air is introduced into the shallow floor plenum by 12 new supply air risers. These are distributed around the perimeter and served from lateral distribution of ductwork accommodated within a 900mm-deep floor at level one. Partway through demolition, sections of the original, ornate, pressed-metal ceiling cornices were discovered on level one, which was being converted into the main trading floor. The in-desk cooling specification allowed the ceilings and chilled beams in these areas to be omitted, and the cornices fully restored and exposed. The trading floor also extends across the base of the atrium, which again – with no ceiling immediately above – suited an in-desk cooling solution. Cooling units are integrated into the desks and underfloor displacement delivers fresh air drawn from the raised access floor in combination with chilled beams on other levels. This is the first commercial installation of in-desk cooling in Australia. The chilled-beam and in desk cooling solutions require a well-sealed building, particularly in the Sydney climate, which experiences sustained periods of high temperature and humidity. The building fabric was pressure tested byArup during the early design phase and performed surprisingly well, with only window seals needing replacement.

For the full article on the CIBSE website <a _cke_saved_href="http://www.cibsejournal.com/" _fcknotitle="true" href="http://www.cibsejournal.com/">click here</a>.

Restoration of 50 Martin Place, Sydney

2014-11-21T14:25:24Z

CIBSE:

Restoration of 50 Martin Place, Sydney

2014-11-21T14:10:33Z

CIBSE:

Article from the <a href="http://www.cibsejournal.com">November 2014 edition of the CIBSE Journal </a>written by Alex Pettifer.

 
Innovative engineering and careful restoration transformed an Australian Beaux Arts beauty into a global investment bank’s HQ. Arup’s Andrew Pettifer FCIBSE explains how a Sydney belle became hi-tech real estate.

Fifty Martin Place is a historic building in the heart of Sydney’s financial district. Constructed between 1925 and 1928 – for what was then the Government Savings Bank of New South Wales – it is a rare Australian example of the American-influenced, inter-war Beaux Arts style. Macquarie Group, Australia’s only global investment bank, acquired the building in 2012 to create its new corporate headquarters. This was a radical step in the Australian property market where, typically, commercial property is owned and managed by real estate investment trusts. The fact that Macquarie was to be an owner-occupier opened up opportunities both to refurbish an important heritage building, and to create a world-class workspace, specifically designed to meet the bank’s corporate objectives of enhanced performance through connectivity, collaboration and sustainability. Consequently, 50 Martin Place has become the largest historic refurbishment in Australia to be awarded a Six Star Green Star rating – representing ‘ world leadership’ – by the Green Building Council of Australia. The design strategy involved the creation of a glass, domed roof – to house client facilities and meeting rooms – and an enlarged, open-edged atrium. The atrium is the centrepiece of the project, enhancing daylight penetration through the core of the building, while accommodating open stairs that provide connectivity between office floors. The strategy presented Arup, the sustainable design and building services consultant for the project, with a number of challenges. The first was to remove as much plant as possible from the roof to free up space for client use. Plant that remained at roof level – including cooling towers, standby generators and smoke exhaust fans – was carefully integrated into the new glazed structure, to minimise the intrusion into the architectural form. Other plant was sensitively relocated to reduce the impact on the historic fabric of the building. This included the conversion of original water tanks into fan- and boiler- plant rooms, and the relocation of chillers from the roof to the basement. An existing light well was used as a fresh-air intake, and worked in tandem with the atrium, which acted as the exhaust air path. The office air conditioning solution uses passive chilled beams, coupled with fresh air supply delivered through a 250 mm-high raised-access floor. The combination is Australia’s first example of such an approach (see panel, ‘Air conditioning’).
<h2>
Seeing the light</h2>

Given the heritage of 50 Martin Place, its façade has far less glazing than contemporary buildings, and access to daylight and views is well below modern expectations. A key design objective of the project, therefore, was to bring daylight, sky views, and interconnectivity from the top of building to its core. This was achieved through the transparent new roof structure and the enlargement of the existing narrow atrium, to increase daylight penetration into the building, while creating a visual point of connection to the outdoors. Innovative glazing technology – comprising triple glazing with an inbuilt extruded mesh – creates a high-performing fabric. The result is superior thermal comfort, ample daylight, and extensive sky views. Architecturally, the result is a transparent volume, clearly demarcating the new and the old, and respecting the history of the building. Extensive daylight analysis was conducted, to demonstrate to the Heritage Council of NSW the environmental benefits of increasing the atrium size. The analysis quantified the benefits of increasing the atrium width for daylight penetration on the floor plates, and within the atrium. Further studies were conducted to determine the best configuration for the internal stairs interconnecting the atrium to ensure the stairs allowed as much daylight as possible to reach the bottom of the space. The results of the analysis showed daylight reach within the atrium would extend three storeys deeper, compared with the existing building. Useful daylight penetration into the office space was increased by approximately 150%. Modelling was also undertaken to assess sunlight penetration, and an automatic blind system will shade the atrium floor during the relatively few hours in a year when the sun is sufficiently high to penetrate the office space.
<h2>
Lighting</h2>

The office lighting layout was developed to reinforce the structural and ceiling grid in the original building, and to expose the historic fabric previously hidden behind the ceiling. The offices and atrium have perimeter, ceiling-mounted daylight sensors that dim the adjacent lighting when sufficient daylight reaches the work desks. To maximise the effect of the widened atrium, it was decided not to add any further equipment to light the void. Vertical circulation lighting is managed using integrated balustrade lighting in the stair. This also plays on the perforated balustrade panels, giving the stair the appearance of a glowing ribbon rising up through the generous space. At high level, the need to mount luminaires beneath the glazing has been avoided by the design of self-illuminated glass bridges. At the base of the atrium, an indirect mirror system is used to redirect light to the traders. The luminaires and mirrors are mounted to the exposed beams at the perimeter of the void, to provide clear views up through the atrium.
<h2>
Fire Safety Engineering</h2>

While the large open atrium allows daylight to penetrate deep into the building, it did provide the engineers with a tough challenge in terms of fire safety. The Building Code of Australia limits the number of floors that can be connected via openings to two above ground, although any number may be connected via a sealed atrium. The requirements for a sealed atrium are onerous, with glazing and wall-wetting systems, smoke exhaust, emergency power, multiple exit routes for any balconies, and – importantly – no real connection to the floors. This did not meet Macquarie’s desire for the atrium to be open and therefore enhance connectivity and collaboration within the business. To achieve an open-edged atrium – and provide the required interconnectivity – a performance-based, fire-engineering design was developed by Arup’s fire engineers. In the event of fire, the non-fire floors are smoke-separated from the atrium by a combination of drop-down smoke curtains and glazed panels, required to resolve tricky etailing around large heritage beams. The fire floor remains open to the atrium, and large smoke exhaust fans extract from the top of the atrium at a rate of 40 m 3/hr, while make-up air comes from automation of existing heritage balcony doors at level two,combined with the general supply air system. The new client floors constructed within the glass-dome roof extension are open to the atrium. For these floors, exiting through a smoke-proof construction to fire-escape stairs – off an external terrace – enables occupants to move to a place of relative safety before evacuating. This approach allows for high-occupant numbers to be accommodated within the client entertaining areas. Sprinklers are provided throughout the building to keep fire sizes low. Smoke detection – including beam detection in the atrium – provides for early warning, while pressurised escape routes give people time to evacuate the fire floor and those adjacent to it, simultaneously. There is staged evacuation for the remaining floors. Another significant task was to upgrade the numerous styles of heritage luminaires on the original staircases and the halls, some of which were gas mantle luminaires. To upgrade the historic fittings, a number of diffuse LED sources were developed, effectively replicating the optical distribution of older tungsten lamps, while increasing the lumen output to meet the egress requirements.
<h2>
Summary</h2>

50 Martin Place demonstrates how new life can be breathed into a historic building, to create an exciting contemporary workplace. The project highlights that the unique characteristics of such a construction requires highly bespoke engineering solutions. The result, however, is a building that is prudent in the reuse of existing resources, energy efficient in performance, and – most importantly – meets the client’s objectives of creating an inspiring and efficient place to work.
<h2>
Air conditioning</h2>

The general office air-conditioning solution uses passive chilled beams, coupled with dehumidified fresh air supply, delivered through swirl outlets in a 250 mm-high raised-access floor, acting as a plenum. Raised-access flooring systems are not common in the Australian commercial market, and the combination of chilled beams with supply air through the floor at 50 Martin Place is the country’s first example of such an approach. Mindful of the potential leakiness of the heritage structure, the raised floor plenums went through rigorous pressure testing on site, to ensure that performance requirements were met. The swirl outlets were specified to have an adjustable throw pattern of +/-30 degrees from the vertical, to provide occupants with the opportunity to adjust the air distribution in their vicinity.The ceiling-level services have been carefully arranged to complement the original ceiling design, and allow the 1920s structural grid to be exposed. Passive chilled beams enabled the ceiling to be pushed up within the beam structure, resulting in a 270 mm-deep ceiling zone, bordered by a 450 mm-deep structural beam grid. Full factory testing of the beams, acting in combination with the specified floor diffusers, allowed the design to be verified before installation. To avoid the need for long and deep ductwork runs from the side core configuration at each level, supply air is introduced into the shallow floor plenum by 12 new supply air risers. These are distributed around the perimeter and served from lateral distribution of ductwork accommodated within a 900mm-deep floor at level one. Partway through demolition, sections of the original, ornate, pressed-metal ceiling cornices were discovered on level one, which was being converted into the main trading floor. The in-desk cooling specification allowed the ceilings and chilled beams in these areas to be omitted, and the cornices fully restored and exposed. The trading floor also extends across the base of the atrium, which again – with no ceiling immediately above – suited an in-desk cooling solution. Cooling units are integrated into the desks and underfloor displacement delivers fresh air drawn from the raised access floor in combination with chilled beams on other levels. This is the first commercial installation of in-desk cooling in Australia. The chilled-beam and in desk cooling solutions require a well-sealed building, particularly in the Sydney climate, which experiences sustained periods of high temperature and humidity. The building fabric was pressure tested byArup during the early design phase and performed surprisingly well, with only window seals needing replacement.

Restoration of 50 Martin Place, Sydney

2014-11-21T14:08:45Z

CIBSE:

Article from the <a href="http://www.cibsejournal.com">November 2014 edition of the CIBSE Journal </a>written by Alex Pettifer.

 
Innovative engineering and careful restoration transformed an Australian Beaux Arts beauty into a global investment bank’s HQ. Arup’s Andrew Pettifer FCIBSE explains how a Sydney belle became hi-tech real estate.

Fifty Martin Place is a historic building in the heart of Sydney’s financial district. Constructed between 1925 and 1928 – for what was then the Government Savings Bank of New South Wales – it is a rare Australian example of the American-influenced, inter-war Beaux Arts style. Macquarie Group, Australia’s only global investment bank, acquired the building in 2012 to create its new corporate headquarters. This was a radical step in the Australian property market where, typically, commercial property is owned and managed by real estate investment trusts. The fact that Macquarie was to be an owner-occupier opened up opportunities both to refurbish an important heritage building, and to create a world-class workspace, specifically designed to meet the bank’s corporate objectives of enhanced performance through connectivity, collaboration and sustainability. Consequently, 50 Martin Place has become the largest historic refurbishment in Australia to be awarded a Six Star Green Star rating – representing ‘ world leadership’ – by the Green Building Council of Australia. The design strategy involved the creation of a glass, domed roof – to house client facilities and meeting rooms – and an enlarged, open-edged atrium. The atrium is the centrepiece of the project, enhancing daylight penetration through the core of the building, while accommodating open stairs that provide connectivity between office floors. The strategy presented Arup, the sustainable design and building services consultant for the project, with a number of challenges. The first was to remove as much plant as possible from the roof to free up space for client use. Plant that remained at roof level – including cooling towers, standby generators and smoke exhaust fans – was carefully integrated into the new glazed structure, to minimise the intrusion into the architectural form. Other plant was sensitively relocated to reduce the impact on the historic fabric of the building. This included the conversion of original water tanks into fan- and boiler- plant rooms, and the relocation of chillers from the roof to the basement. An existing light well was used as a fresh-air intake, and worked in tandem with the atrium, which acted as the exhaust air path. The office air conditioning solution uses passive chilled beams, coupled with fresh air supply delivered through a 250 mm-high raised-access floor. The combination is Australia’s first example of such an approach (see panel, ‘Air conditioning’).

Seeing the light

Given the heritage of 50 Martin Place, its façade has far less glazing than contemporary buildings, and access to daylight and views is well below modern expectations. A key design objective of the project, therefore, was to bring daylight, sky views, and interconnectivity from the top of building to its core. This was achieved through the transparent new roof structure and the enlargement of the existing narrow atrium, to increase daylight penetration into the building, while creating a visual point of connection to the outdoors. Innovative glazing technology – comprising triple glazing with an inbuilt extruded mesh – creates a high-performing fabric. The result is superior thermal comfort, ample daylight, and extensive sky views. Architecturally, the result is a transparent volume, clearly demarcating the new and the old, and respecting the history of the building. Extensive daylight analysis was conducted, to demonstrate to the Heritage Council of NSW the environmental benefits of increasing the atrium size. The analysis quantified the benefits of increasing the atrium width for daylight penetration on the floor plates, and within the atrium. Further studies were conducted to determine the best configuration for the internal stairs interconnecting the atrium to ensure the stairs allowed as much daylight as possible to reach the bottom of the space. The results of the analysis showed daylight reach within the atrium would extend three storeys deeper, compared with the existing building. Useful daylight penetration into the office space was increased by approximately 150%. Modelling was also undertaken to assess sunlight penetration, and an automatic blind system will shade the atrium floor during the relatively few hours in a year when the sun is sufficiently high to penetrate the office space.

Lighting

The office lighting layout was developed to reinforce the structural and ceiling grid in the original building, and to expose the historic fabric previously hidden behind the ceiling. The offices and atrium have perimeter, ceiling-mounted daylight sensors that dim the adjacent lighting when sufficient daylight reaches the work desks. To maximise the effect of the widened atrium, it was decided not to add any further equipment to light the void. Vertical circulation lighting is managed using integrated balustrade lighting in the stair. This also plays on the perforated balustrade panels, giving the stair the appearance of a glowing ribbon rising up through the generous space. At high level, the need to mount luminaires beneath the glazing has been avoided by the design of self-illuminated glass bridges. At the base of the atrium, an indirect mirror system is used to redirect light to the traders. The luminaires and mirrors are mounted to the exposed beams at the perimeter of the void, to provide clear views up through the atrium.

Fire Safety Engineering

While the large open atrium allows daylight to penetrate deep into the building, it did provide the engineers with a tough challenge in terms of fire safety. The Building Code of Australia limits the number of floors that can be connected via openings to two above ground, although any number may be connected via a sealed atrium. The requirements for a sealed atrium are onerous, with glazing and wall-wetting systems, smoke exhaust, emergency power, multiple exit routes for any balconies, and – importantly – no real connection to the floors. This did not meet Macquarie’s desire for the atrium to be open and therefore enhance connectivity and collaboration within the business. To achieve an open-edged atrium – and provide the required interconnectivity – a performance-based, fire-engineering design was developed by Arup’s fire engineers. In the event of fire, the non-fire floors are smoke-separated from the atrium by a combination of drop-down smoke curtains and glazed panels, required to resolve tricky etailing around large heritage beams. The fire floor remains open to the atrium, and large smoke exhaust fans extract from the top of the atrium at a rate of 40 m 3/hr, while make-up air comes from automation of existing heritage balcony doors at level two,combined with the general supply air system. The new client floors constructed within the glass-dome roof extension are open to the atrium. For these floors, exiting through a smoke-proof construction to fire-escape stairs – off an external terrace – enables occupants to move to a place of relative safety before evacuating. This approach allows for high-occupant numbers to be accommodated within the client entertaining areas. Sprinklers are provided throughout the building to keep fire sizes low. Smoke detection – including beam detection in the atrium – provides for early warning, while pressurised escape routes give people time to evacuate the fire floor and those adjacent to it, simultaneously. There is staged evacuation for the remaining floors. Another significant task was to upgrade the numerous styles of heritage luminaires on the original staircases and the halls, some of which were gas mantle luminaires. To upgrade the historic fittings, a number of diffuse LED sources were developed, effectively replicating the optical distribution of older tungsten lamps, while increasing the lumen output to meet the egress requirements.

Summary

50 Martin Place demonstrates how new life can be breathed into a historic building, to create an exciting contemporary workplace. The project highlights that the unique characteristics of such a construction requires highly bespoke engineering solutions. The result, however, is a building that is prudent in the reuse of existing resources, energy efficient in performance, and – most importantly – meets the client’s objectives of creating an inspiring and efficient place to work.

Air conditioning

The general office air-conditioning solution uses passive chilled beams, coupled with dehumidified fresh air supply, delivered through swirl outlets in a 250 mm-high raised-access floor, acting as a plenum. Raised-access flooring systems are not common in the Australian commercial market, and the combination of chilled beams with supply air through the floor at 50 Martin Place is the country’s first example of such an approach. Mindful of the potential leakiness of the heritage structure, the raised floor plenums went through rigorous pressure testing on site, to ensure that performance requirements were met. The swirl outlets were specified to have an adjustable throw pattern of +/-30 degrees from the vertical, to provide occupants with the opportunity to adjust the air distribution in their vicinity.The ceiling-level services have been carefully arranged to complement the original ceiling design, and allow the 1920s structural grid to be exposed. Passive chilled beams enabled the ceiling to be pushed up within the beam structure, resulting in a 270 mm-deep ceiling zone, bordered by a 450 mm-deep structural beam grid. Full factory testing of the beams, acting in combination with the specified floor diffusers, allowed the design to be verified before installation. To avoid the need for long and deep ductwork runs from the side core configuration at each level, supply air is introduced into the shallow floor plenum by 12 new supply air risers. These are distributed around the perimeter and served from lateral distribution of ductwork accommodated within a 900mm-deep floor at level one. Partway through demolition, sections of the original, ornate, pressed-metal ceiling cornices were discovered on level one, which was being converted into the main trading floor. The in-desk cooling specification allowed the ceilings and chilled beams in these areas to be omitted, and the cornices fully restored and exposed. The trading floor also extends across the base of the atrium, which again – with no ceiling immediately above – suited an in-desk cooling solution. Cooling units are integrated into the desks and underfloor displacement delivers fresh air drawn from the raised access floor in combination with chilled beams on other levels. This is the first commercial installation of in-desk cooling in Australia. The chilled-beam and in desk cooling solutions require a well-sealed building, particularly in the Sydney climate, which experiences sustained periods of high temperature and humidity. The building fabric was pressure tested byArup during the early design phase and performed surprisingly well, with only window seals needing replacement.

Restoration of 50 Martin Place, Sydney

2014-11-21T14:03:14Z

CIBSE:

Article from the [http://portfolio.cpl.co.uk/CIBSE/201410/post-occupancy-evaluation-woodland-trust-hq/ November 2014 edition of the CIBSE Journal] written by Alex Pettifer. 

Innovative engineering and careful restoration transformed an Australian Beaux Arts beauty into a global investment bank’s HQ. Arup’s Andrew Pettifer FCIBSE explains how a Sydney belle became hi-tech real estate

Fifty Martin Place is a historic building in the heart of Sydney’s financial district. Constructed between 1925 and 1928 – for what was then the Government Savings Bank of New South Wales – it is a rare Australian example of the American-influenced, inter-war Beaux Arts style. Macquarie Group, Australia’s only global investment bank, acquired the building in 2012 to create its new corporate headquarters. This was a radical step in the Australian property market where, typically, commercial property is owned and managed by real estate investment trusts. The fact that Macquarie was to be an owner-occupier opened up opportunities both to refurbish an important heritage building, and to create a world-class workspace, specifically designed to meet the bank’s corporate objectives of enhanced performance through connectivity, collaboration and sustainability.

Consequently, 50 Martin Place has become the largest historic refurbishment in Australia to be awarded a Six Star Green Star rating – representing ‘ world leadership’ – by the Green Building Council of Australia. The design strategy involved the creation of a glass, domed roof – to house client facilities and meeting rooms – and an enlarged, open-edged atrium. The atrium is the centrepiece of the project, enhancing daylight penetration through the core of the building, while accommodating open stairs that provide connectivity between office floors.

The strategy presented Arup, the sustainable design and building services consultant for the project, with a number of challenges. The first was to remove as much plant as possible from the roof to free up space for client use. Plant that remained at roof level – including cooling towers, standby generators and smoke exhaust fans – was carefully integrated into the new glazed structure, to minimise the intrusion into the architectural form. Other plant was sensitively relocated to reduce the impact on the historic fabric of the building. This included the conversion of original water tanks into fan- and boiler- plant rooms, and the relocation of chillers from the roof to the basement. An existing light well was used as a fresh-air intake, and worked in tandem with the atrium, which acted as the exhaust air path. The office air conditioning solution uses passive chilled beams, coupled with fresh air supply delivered through a 250 mm-high raised-access floor. The combination is Australia’s first example of such an approach (see panel, ‘Air conditioning’).

== Seeing the light ==

Given the heritage of 50 Martin Place, its façade has far less glazing than contemporary buildings, and access to daylight and views is well below modern expectations. A key design objective of the project, therefore, was to bring daylight, sky views, and interconnectivity from the top of building to its core. This was achieved through the transparent new roof structure and the enlargement of the existing narrow atrium, to increase daylight penetration into the building, while creating a visual point of connection to the outdoors. Innovative glazing technology – comprising triple glazing with an inbuilt extruded mesh – creates a high-performing fabric. The result is superior thermal comfort, ample daylight, and extensive sky views. Architecturally, the result is a transparent volume, clearly demarcating the new and the old, and respecting the history of the building.

Extensive daylight analysis was conducted, to demonstrate to the Heritage Council of NSW the environmental benefits of increasing the atrium size. The analysis quantified the benefits of increasing the atrium width for daylight penetration on the floor plates, and within the atrium. Further studies were conducted to determine the best configuration for the internal stairs interconnecting the atrium to ensure the stairs allowed as much daylight as possible to reach the bottom of the space. The results of the analysis showed daylight reach within the atrium would extend three storeys deeper, compared with the existing building. Useful daylight penetration into the office space was increased by approximately 150%. Modelling was also undertaken to assess sunlight penetration, and an automatic blind system will shade the atrium floor during the relatively few hours in a year when the sun is sufficiently high to penetrate the office space.

== Lighting ==

The office lighting layout was developed to reinforce the structural and ceiling grid in the original building, and to expose the historic fabric previously hidden behind the ceiling. The offices and atrium have perimeter, ceiling-mounted daylight sensors that dim the adjacent lighting when sufficient daylight reaches the work desks. To maximise the effect of the widened atrium, it was decided not to add any further equipment to light the void. Vertical circulation lighting is managed using integrated balustrade lighting in the stair. This also plays on the perforated balustrade panels, giving the stair the appearance of a glowing ribbon rising up through the generous space. At high level, the need to mount luminaires beneath the glazing has been avoided by the design of self-illuminated glass bridges. At the base of the atrium, an indirect mirror system is used to redirect light to the traders. The luminaires and mirrors are mounted to the exposed beams at the perimeter of the void, to provide clear views up through the atrium.

== Fire Safety Engineering ==

While the large open atrium allows daylight to penetrate deep into the building, it did provide the engineers with a tough challenge in terms of fire safety. The Building Code of Australia limits the number of floors that can be connected via openings to two above ground, although any number may be connected via a sealed atrium. The requirements for a sealed atrium are onerous, with glazing and wall-wetting systems, smoke exhaust, emergency power, multiple exit routes for any balconies, and – importantly – no real connection to the floors. This did not meet Macquarie’s desire for the atrium to be open and therefore enhance connectivity and collaboration within the business. To achieve an open-edged atrium – and provide the required interconnectivity – a performance-based, fire-engineering design was developed by Arup’s fire engineers. In the event of fire, the non-fire floors are smoke-separated from the atrium by a combination of drop-down smoke curtains and glazed panels, required to resolve tricky etailing around large heritage beams.

The fire floor remains open to the atrium, and large smoke exhaust fans extract from the top of the atrium at a rate of 40 m 3/hr, while make-up air comes from automation of existing heritage balcony doors at level two,combined with the general supply air system. The new client floors constructed within the glass-dome roof extension are open to the atrium. For these floors, exiting through a smoke-proof construction to fire-escape stairs – off an external terrace – enables occupants to move to a place of relative safety before evacuating.

This approach allows for high-occupant numbers to be accommodated within the client entertaining areas.

Sprinklers are provided throughout the building to keep fire sizes low. Smoke detection – including beam detection in the atrium – provides for early warning, while pressurised escape routes give people time to evacuate the fire floor and those adjacent to it, simultaneously. There is staged evacuation for the remaining floors. Another significant task was to upgrade the numerous styles of heritage luminaires on the original staircases and the halls, some of which were gas mantle luminaires.

To upgrade the historic fittings, a number of diffuse LED sources were developed, effectively replicating the optical distribution of older tungsten lamps, while increasing the lumen output to meet the egress requirements.

== Summary ==

50 Martin Place demonstrates how new life can be breathed into a historic building, to create an exciting contemporary workplace. The project highlights that the unique characteristics of such a construction requires highly bespoke engineering solutions. The result, however, is a building that is prudent in the reuse of existing resources, energy efficient in performance, and – most importantly – meets the client’s objectives of creating an inspiring and efficient place to work.

== Air conditioning ==

The general office air-conditioning solution uses passive chilled beams, coupled with dehumidified fresh air supply, delivered through swirl outlets in a 250 mm-high raised-access floor, acting as a plenum. Raised-access flooring systems are not common in the Australian commercial market, and the combination of chilled beams with supply air through the floor at 50 Martin Place is the country’s first example of such an approach. Mindful of the potential leakiness of the heritage structure, the raised floor plenums went through rigorous pressure testing on site, to ensure that performance requirements were met. The swirl outlets were specified to have an adjustable throw pattern of +/-30 degrees from the vertical, to provide occupants with the opportunity to adjust the air distribution in their vicinity.The ceiling-level services have been carefully arranged to complement the original ceiling design, and allow the 1920s structural grid to be exposed. Passive chilled beams enabled the ceiling to be pushed up within the beam structure, resulting in a 270 mm-deep ceiling zone, bordered by a 450 mm-deep structural beam grid. Full factory testing of the beams, acting in combination with the specified floor diffusers, allowed the design to be verified before installation. To avoid the need for long and deep ductwork runs from the side core configuration at each level, supply air is introduced into the shallow floor plenum by 12 new supply air risers. These are distributed around the perimeter and served from lateral distribution of ductwork accommodated within a 900mm-deep floor at level one.

Partway through demolition, sections of the original, ornate, pressed-metal ceiling cornices were discovered on level one, which was being converted into the main trading floor. The in-desk cooling specification allowed the ceilings and chilled beams in these areas to be omitted, and the cornices fully restored and exposed. The trading floor also extends across the base of the atrium, which again – with no ceiling immediately above – suited an in-desk cooling solution. Cooling units are integrated into the desks and underfloor displacement delivers fresh air drawn from the raised access floor in combination with chilled beams on other levels.

This is the first commercial installation of in-desk cooling in Australia. The chilled-beam and in desk cooling solutions require a well-sealed building, particularly in the Sydney climate, which experiences sustained periods of high temperature and humidity. The building fabric was pressure tested byArup during the early design phase and performed surprisingly well, with only window seals needing replacement.

Restoration of 50 Martin Place, Sydney

2014-11-21T13:58:51Z

CIBSE: Created page with " Innovative engineering and careful restoration transformed an Australian Beaux Arts beauty into a global investment bank’s HQ. Arup’s Andrew Pettifer FCIBSE explains how a ..."

Innovative engineering and careful restoration transformed an Australian Beaux Arts beauty into a global investment bank’s HQ. Arup’s Andrew Pettifer FCIBSE explains how a Sydney belle became hi-tech real estate

Fifty Martin Place is a historic building in the heart of Sydney’s financial district. Constructed between 1925 and 1928 – for what was then the Government Savings Bank of New South Wales – it is a rare Australian example of the American-influenced, inter-war Beaux Arts style. Macquarie Group, Australia’s only global investment bank, acquired the building in 2012 to create its new corporate headquarters. This was a radical step in the Australian property market where, typically, commercial property is owned and managed by real estate investment trusts. The fact that Macquarie was to be an owner-occupier opened up opportunities both to refurbish an important heritage building, and to create a world-class workspace, specifically designed to meet the bank’s corporate objectives of enhanced performance through connectivity, collaboration and sustainability.

Consequently, 50 Martin Place has become the largest historic refurbishment in Australia to be awarded a Six Star Green Star rating – representing ‘ world leadership’ – by the Green Building Council of Australia. The design strategy involved the creation of a glass, domed roof – to house client facilities and meeting rooms – and an enlarged, open-edged atrium. The atrium is the centrepiece of the project, enhancing daylight penetration through the core of the building, while accommodating open stairs that provide connectivity between office floors.

The strategy presented Arup, the sustainable design and building services consultant for the project, with a number of challenges. The first was to remove as much plant as possible from the roof to free up space for client use. Plant that remained at roof level – including cooling towers, standby generators and smoke exhaust fans – was carefully integrated into the new glazed structure, to minimise the intrusion into the architectural form. Other plant was sensitively relocated to reduce the impact on the historic fabric of the building. This included the conversion of original water tanks into fan- and boiler- plant rooms, and the relocation of chillers from the roof to the basement. An existing light well was used as a fresh-air intake, and worked in tandem with the atrium, which acted as the exhaust air path. The office air conditioning solution uses passive chilled beams, coupled with fresh air supply delivered through a 250 mm-high raised-access floor. The combination is Australia’s first example of such an approach (see panel, ‘Air conditioning’).

Seeing the light

Given the heritage of 50 Martin Place, its façade has far less glazing than contemporary buildings, and access to daylight and views is well below modern expectations. A key design objective of the project, therefore, was to bring daylight, sky views, and interconnectivity from the top of building to its core. This was achieved through the transparent new roof structure and the enlargement of the existing narrow atrium, to increase daylight penetration into the building, while creating a visual point of connection to the outdoors. Innovative glazing technology – comprising triple glazing with an inbuilt extruded mesh – creates a high-performing fabric. The result is superior thermal comfort, ample daylight, and extensive sky views. Architecturally, the result is a transparent volume, clearly demarcating the new and the old, and respecting the history of the building.

Extensive daylight analysis was conducted, to demonstrate to the Heritage Council of NSW the environmental benefits of increasing the atrium size. The analysis quantified the benefits of increasing the atrium width for daylight penetration on the floor plates, and within the atrium. Further studies were conducted to determine the best configuration for the internal stairs interconnecting the atrium to ensure the stairs allowed as much daylight as possible to reach the bottom of the space. The results of the analysis showed daylight reach within the atrium would extend three storeys deeper, compared with the existing building. Useful daylight penetration into the office space was increased by approximately 150%. Modelling was also undertaken to assess sunlight penetration, and an automatic blind system will shade the atrium floor during the relatively few hours in a year when the sun is sufficiently high to penetrate the office space.

Lighting

The office lighting layout was developed to reinforce the structural and ceiling grid in the original building, and to expose the historic fabric previously hidden behind the ceiling. The offices and atrium have perimeter, ceiling-mounted daylight sensors that dim the adjacent lighting when sufficient daylight reaches the work desks. To maximise the effect of the widened atrium, it was decided not to add any further equipment to light the void. Vertical circulation lighting is managed using integrated balustrade lighting in the stair. This also plays on the perforated balustrade panels, giving the stair the appearance of a glowing ribbon rising up through the generous space. At high level, the need to mount luminaires beneath the glazing has been avoided by the design of self-illuminated glass bridges. At the base of the atrium, an indirect mirror system is used to redirect light to the traders. The luminaires and mirrors are mounted to the exposed beams at the perimeter of the void, to provide clear views up through the atrium.

Fire Safety Engineering

While the large open atrium allows daylight to penetrate deep into the building, it did provide the engineers with a tough challenge in terms of fire safety. The Building Code of Australia limits the number of floors that can be connected via openings to two above ground, although any number may be connected via a sealed atrium. The requirements for a sealed atrium are onerous, with glazing and wall-wetting systems, smoke exhaust, emergency power, multiple exit routes for any balconies, and – importantly – no real connection to the floors. This did not meet Macquarie’s desire for the atrium to be open and therefore enhance connectivity and collaboration within the business. To achieve an open-edged atrium – and provide the required interconnectivity – a performance-based, fire-engineering design was developed by Arup’s fire engineers. In the event of fire, the non-fire floors are smoke-separated from the atrium by a combination of drop-down smoke curtains and glazed panels, required to resolve tricky etailing around large heritage beams.

The fire floor remains open to the atrium, and large smoke exhaust fans extract from the top of the atrium at a rate of 40 m 3/hr, while make-up air comes from automation of existing heritage balcony doors at level two,combined with the general supply air system. The new client floors constructed within the glass-dome roof extension are open to the atrium. For these floors, exiting through a smoke-proof construction to fire-escape stairs – off an external terrace – enables occupants to move to a place of relative safety before evacuating.

This approach allows for high-occupant numbers to be accommodated within the client entertaining areas.

Sprinklers are provided throughout the building to keep fire sizes low. Smoke detection – including beam detection in the atrium – provides for early warning, while pressurised escape routes give people time to evacuate the fire floor and those adjacent to it, simultaneously. There is staged evacuation for the remaining floors. Another significant task was to upgrade the numerous styles of heritage luminaires on the original staircases and the halls, some of which were gas mantle luminaires.

To upgrade the historic fittings, a number of diffuse LED sources were developed, effectively replicating the optical distribution of older tungsten lamps, while increasing the lumen output to meet the egress requirements.

Summary

50 Martin Place demonstrates how new life can be breathed into a historic building, to create an exciting contemporary workplace. The project highlights that the unique characteristics of such a construction requires highly bespoke engineering solutions. The result, however, is a building that is prudent in the reuse of existing resources, energy efficient in performance, and – most importantly – meets the client’s objectives of creating an inspiring and efficient place to work.

Air conditioning

The general office air-conditioning solution uses passive chilled beams, coupled with dehumidified fresh air supply, delivered through swirl outlets in a 250 mm-high raised-access floor, acting as a plenum. Raised-access flooring systems are not common in the Australian commercial market, and the combination of chilled beams with supply air through the floor at 50 Martin Place is the country’s first example of such an approach. Mindful of the potential leakiness of the heritage structure, the raised floor plenums went through rigorous pressure testing on site, to ensure that performance requirements were met. The swirl outlets were specified to have an adjustable throw pattern of +/-30 degrees from the vertical, to provide occupants with the opportunity to adjust the air distribution in their vicinity.The ceiling-level services have been carefully arranged to complement the original ceiling design, and allow the 1920s structural grid to be exposed. Passive chilled beams enabled the ceiling to be pushed up within the beam structure, resulting in a 270 mm-deep ceiling zone, bordered by a 450 mm-deep structural beam grid. Full factory testing of the beams, acting in combination with the specified floor diffusers, allowed the design to be verified before installation. To avoid the need for long and deep ductwork runs from the side core configuration at each level, supply air is introduced into the shallow floor plenum by 12 new supply air risers. These are distributed around the perimeter and served from lateral distribution of ductwork accommodated within a 900mm-deep floor at level one.

Partway through demolition, sections of the original, ornate, pressed-metal ceiling cornices were discovered on level one, which was being converted into the main trading floor. The in-desk cooling specification allowed the ceilings and chilled beams in these areas to be omitted, and the cornices fully restored and exposed. The trading floor also extends across the base of the atrium, which again – with no ceiling immediately above – suited an in-desk cooling solution. Cooling units are integrated into the desks and underfloor displacement delivers fresh air drawn from the raised access floor in combination with chilled beams on other levels.

This is the first commercial installation of in-desk cooling in Australia. The chilled-beam and in desk cooling solutions require a well-sealed building, particularly in the Sydney climate, which experiences sustained periods of high temperature and humidity. The building fabric was pressure tested byArup during the early design phase and performed surprisingly well, with only window seals needing replacement.

Performance in use of National Trust’s Heelis building and Woodland Trust’s headquarters

2014-10-02T13:59:41Z

CIBSE:

Article from the October 2014 edition of the CIBSE Journal written by Bill Bordass, Pete Burgon, Hester Brough and Matt Vaudin.

 Experience gained from the post-occupancy evaluation of the National Trust’s Heelis building have been fed into the design of The Woodland Trust’s headquarters. The project team compares the in-use performance of both. To maintain the ‘golden thread’ from design intent to reality when creating the 2,727m2 head office for The Woodland Trust, Max Fordham – and architect Feilden Clegg Bradley Studios – used post-occupancy findings from the Heelis building, in Swindon. The outcomes have now been studied, thanks to funding from Innovate UK – formerly the Technology Strategy Board – and its Building Performance Evaluation programme. In 2002-04, the environmental engineer and architect formed part of a research team investigating the potential for soft landings (1), and discovered the importance of maintaining the ‘golden thread’ – starting with inception and briefing, then managing expectations throughout the procurement process, building on initial aftercare, post-occupancy evaluation, and closing the feedback loop.

== Gathering data ==

At that time, Max Fordham and Feilden Clegg Bradley Studios were working together on Heelis, the National Trust’s 7,605m2 (gross) head office in Swindon. The project followed a strong sustainability agenda, though this was somewhat softened by the requirements of the developer, which procured the building after the scheme design had been agreed with the client. As part of the reality checking advocated by soft landings, a matrix was developed by Feilden Clegg Bradley Studios and Max Fordham, to allow design ambitions for sustainability to be reviewed at project meetings. Max Fordham was also appointed to fine-tune the operation of the mixed-mode building for two years after handover. The Heelis findings were published in Building Services Journal (2) in November 2007. Feilden Clegg Bradley Studios also commissioned William Bordass Associates and Building Use Studies to undertake a postoccupancy review, similar to the Probe studies published in Building Services Journal from 1995-2002 (3).

== Learning from Heelis ==

A key ﬁnding from Heelis was to avoid unmanageable complications. Measures adopted at The Woodland Trust included: ● A traditional contract. The developer-led procurement at Heelis did not allow some elements to evolve as the designers would have preferred ● The steel frame of Heelis had problems with airtightness and thermal bridging. The Woodland Trust, therefore, used a solid, cross-laminated timber (CLT) structure, with external wood-fibre insulation and larch rain-screen cladding. Concrete panels (known as concrete radiators) were also bolted onto the undersides of the CLT floors, to add stiffness and thermal capacity ● Heelis was mixed-mode, with windows that open, automated night ventilation – using motorised inlet panels and the negative pressure roof outlets – and background MVHR in winter. The Woodland Trust used natural ventilation only, with manual windows at desk level and motorised ones at higher level ● Heelis had suspended and recessed ceilingmounted fittings, with occupancy sensing and dimming. The Woodland Trust had a simpler system, with ambient lighting controlled by an area time switch – or from reception – and task lighting by occupants. Corridors, stairs, WCs, and support spaces used self-contained occupancy sensors. Meeting rooms had manual controls ● The design at Heelis optimised daylight factors (see panel, ‘Atrium at Heelis’, right), but took less account of the brightness of walls and ceilings. As a result, some areas could feel gloomy when desktop illuminances were sufficient. Ambient lighting at The Woodland Trust, therefore, included wall-washing (see panel, ‘Woodland Trust: North Atrium’, page 22) ● The catering kitchen at Heelis used considerably more energy than anticipated. The Woodland Trust decided not to have one ● The ICT system at Heelis had used more electricity than anticipated. The Woodland Trust, therefore, chose ‘thin clients’ in place of PCs. This – and good use of daylight – also helped to reduce unwanted heat gains into the office space ● Both server rooms combined chilled water systems with free cooling. However, value engineering at The Woodland Trust changed this from airside to waterside free cooling ● Both buildings had relatively standard heating systems, with three gas boilers, perimeter trench heating – with a compensated flow temperature – and local zoning, using two-port valves. The Woodland Trust’s plant was more compact and efficient, with lightweight condensing boilers. Heelis had cast-iron boilers, with only one condensing ● At Heelis, using the heating plant to produce domestic hot water (DHW) proved inefficient in summer, so the post-occupancy evaluation suggested an independent hot water boiler. The designers did not take up this recommendation for The Woodland Trust, as it had more efficient plant, and no catering kitchen.

== Occupant satisfaction ==

Figure 1 compares average scores for headline indicators from the BUS Methodology occupant questionnaire surveys. The satisfaction scales run from 1 (poor, on the left) to 7 (good), apart from the final question – on perceived productivity – which goes from -40% to +40%. The flashes above each of the scales represents the benchmark from the BUS reference dataset for that variable, with the 95% confidence limits. The points are coloured red if they are statistically significantly below the benchmark, green if they are above, and orange if similar. For consistency, BUS 2011 office benchmarks are used for both buildings (2004 benchmarks were originally used for Heelis). The profiles are similar for both buildings. In detail: ● Heelis rated worse on winter temperature and summer air quality. This partly related to initial control problems. The situation was improved the following year ● The lower perceived productivity at Heelis was probably because many staff had relocated from other parts of the country. The Woodland Trust moved just 200 metres ● Noise at The Woodland Trust was the only indicator significantly worse than average. This reflects a general deterioration in noise perceptions, owing to more open planning, and higher occupation densities. Many Trust staff were also unaccustomed to open-plan offices. In addition, The Woodland Trust needed to use a space that was acoustically connected to the offices for large meetings and training sessions – activities not anticipated in the brief ● The average score for health at the Trust was linked to less window opening than anticipated, and – perhaps – some initial problems with outgassing. Ventilation control was subsequently improved.

== Energy performance ==

Using standard Building Regulations assumptions, the predicted annual gas consumption was 37.5kWh/m2 GIA at The Woodland Trust. The total in 2012-13 was 32.6kWh/m2, with the heating component, 25.7kWh/m2, almost identical to the design estimate – a very good result in this exceptionally cold year. This also compared well with the 90kWh/m2 for heating and hot water at Heelis, with an additional 24kWh/m2 for its catering kitchen. Figure 2 shows annual electricity consumption – in kWh/m2 –for the same period, broken down by end use. Starting at the bottom, this shows: ● The estimated breakdown for Heelis in 2006. Note the large proportion attributable to the server room and catering kitchen. Not shown is its 9kWh/m2 renewable contribution from PV ● The design estimate for The Woodland Trust, using standard assumptions for Building Regulations, plus Max Fordham’s estimates for the server room ● In-use performance at the Trust in 2012-13. Note the much lower consumption of the lighting and the ICT in relation to the small power allowance. However, much of this reduction reappeared in the server room and its air-conditioning ● Potential future savings using relatively lowcost measures – predominantly switching off the VoIP telephones outside office hours (plus associated savings on the switch, UPS and associated air conditioning), and improved control of the backup cooling units in the server room and the ambient lighting. == Issues in operation == Generally, The Woodland Trust building performed well, but some problems arose in use – of which server-room cooling was the most critical. Value engineering at a relatively late stage replaced the independent airside and chilled water cooling systems with a packaged chiller, with both refrigerant and free cooling. Although the chiller was highly specified, it failed every few months, bringing down the Trust’s entire ICT, thin client, and telephone systems. The manufacturer was remote and local support proved difficult to obtain, so a basic DX backup system had to be added. The chiller’s controls proved to be vulnerable to brief power interruptions, which are common in Grantham. Although the problems were eventually fixed, simple, more standard equipment would have been preferable. Using the boiler plant for both heating and hot water also led to some energy wastage, because of interactions between the two systems. A reduction of nearly 10% in gas consumption was estimated had the systems been completely separated. The natural ventilation system initially caused problems. In winter, occupants opened windows less than expected because of draughts (the main openings are at desk level). When CO2 levels rose above 1,200ppm, the automated system opened higher-level windows, but the minimum setting of 10% was also draughty. The BMS was eventually altered to give facilities control over minimum window opening. In summer, night cooling was also disappointing initially, partly because of a complicated control logic and convection currents reaching the external airtemperature sensor when the sun’s rays fell on the building’s timber rain-screen cladding, elevating the detected temperature by as much as 8°C. The situation was improved by relocating the sensor, simplifying the logic, and allowing the facilities manager to decide whether heating or night cooling was required. The function of the concrete radiators was explored in 2012-13, using heat-flux sensing and time-lapse infrared thermography. The average rate of heat absorption during office hours was 5W/m2, rising to 10W/m2 on hot days. An important finding was a need to close windows an hour before the office opened, so temperatures could equilibrate, otherwise the air and furniture could feel too cool when people arrived (see panel ‘Night cooling and concrete radiators’, right.)

== Conclusions ==

The building achieved many of its design objectives: good quality at a normal cost (£1,800/m2), and good levels of occupant satisfaction – though with shortcomings in relation to noise, in particular. Initial problems with air quality and summertime temperature have been tackled, with potential for further fine-tuning. Lower energy use than Heelis was achieved for all building-related end uses, especially heating and lighting. However, despite ‘thin clients’ and other efforts, the electricity used by ICT systems was higher. Future projects would benefit from the services of an ICT energy-efficiency consultant. The ‘keep it simple and do it well’ approach could be taken further still, particularly by improving the usability of control systems, and avoiding over-complication in the name of energy efficiency – especially in the design of the server room cooling system. In terms of procurement, future projects should: ● Adopt soft landings and manage it firmly from the outset, with champions identified to carry it forward throughout a project ● Make better provision for follow-through after practical completion. Fine-tuning will always be necessary – this should be planned for, including a contingency budget to allow any minor alterations to be dealt with quickly and effectively ● Appreciate the need for constant feedback. With each project there are new things to learn; a problem addressed is not necessarily solved; and unintended consequences may emerge. References: 1 The Soft Landings Framework published by BSRIA and UBT in 2009, drew upon this research work, subsequent case studies, and the activities of the user group hosted by BSRIA. Download it from www.usablebuildings.co.uk 2 G Nevill, So, how are you doing? Building Services, Building Services Journal, 32-37 (November 2007). 3 The original Probe articles can be downloaded at www.cibse.org/knowledge/probe-post-occupancy-studies Bill Bordass FCIBSE, of William Bordass Associates and the Usable Buildings Trust, Pete Burgon CEng MCIBSE, of Max Fordham, Hester Brough, of Feilden Clegg Bradley Studios, and Matt Vaudin, of Stonewood Design

For the full article on the CIBSE homepage [http://portfolio.cpl.co.uk/CIBSE/201410/post-occupancy-evaluation-woodland-trust-hq/ click here].

Performance in use of National Trust’s Heelis building and Woodland Trust’s headquarters

2014-10-02T13:55:39Z

CIBSE:

Article from the October 2014 edition of the CIBSE Journal written by Bill Bordass, Pete Burgon, Hester Brough and Matt Vaudin.

 
Experience gained from the post-occupancy evaluation of the National Trust’s Heelis building have been fed into the design of The Woodland Trust’s headquarters. The project team compares the in-use performance of both. 
 
To maintain the ‘golden thread’ from design intent to reality when creating the 2,727m2 head office for The Woodland Trust, Max Fordham – and architect Feilden Clegg Bradley Studios – used post-occupancy findings from the Heelis building, in Swindon. The outcomes have now been studied, thanks to funding from Innovate UK – formerly the Technology Strategy Board – and its Building Performance Evaluation programme. 
 
In 2002-04, the environmental engineer and architect formed part of a research team investigating the potential for soft landings (1), and discovered the importance of maintaining the ‘golden thread’ – starting with inception and briefing, then managing expectations throughout the procurement process, building on initial aftercare, post-occupancy evaluation, and closing the feedback loop.
<h2>
Gathering data</h2>

At that time, Max Fordham and Feilden Clegg Bradley Studios were working together on Heelis, the National Trust’s 7,605m2 (gross) head office in Swindon. The project followed a strong sustainability agenda, though this was somewhat softened by the requirements of the developer, which procured the building after the scheme design had been agreed with the client. 
 
As part of the reality checking advocated by soft landings, a matrix was developed by Feilden Clegg Bradley Studios and Max Fordham, to allow design ambitions for sustainability to be reviewed at project meetings. Max Fordham was also appointed to fine-tune the operation of the mixed-mode building for two years after handover. The Heelis findings were published in Building Services Journal (2) in November 2007. 
 
Feilden Clegg Bradley Studios also commissioned William Bordass Associates and Building Use Studies to undertake a postoccupancy review, similar to the Probe studies published in Building Services Journal from 1995-2002 (3).
<h2>
Learning from Heelis</h2>

A key ﬁnding from Heelis was to avoid unmanageable complications. Measures adopted at The Woodland Trust included: 
 
● A traditional contract. The developer-led procurement at Heelis did not allow some elements to evolve as the designers would have preferred 
● The steel frame of Heelis had problems with airtightness and thermal bridging. The Woodland Trust, therefore, used a solid, cross-laminated timber (CLT) structure, with external wood-fibre insulation and larch rain-screen cladding. Concrete panels (known as concrete radiators) were also bolted onto the undersides of the CLT floors, to add stiffness and thermal capacity 
● Heelis was mixed-mode, with windows that open, automated night ventilation – using motorised inlet panels and the negative pressure roof outlets – and background MVHR in winter. The Woodland Trust used natural ventilation only, with manual windows at desk level and motorised ones at higher level 
● Heelis had suspended and recessed ceilingmounted fittings, with occupancy sensing and dimming. The Woodland Trust had a simpler system, with ambient lighting controlled by an area time switch – or from reception – and task lighting by occupants. Corridors, stairs, WCs, and support spaces used self-contained occupancy sensors. Meeting rooms had manual controls 
● The design at Heelis optimised daylight factors (see panel, ‘Atrium at Heelis’, right), but took less account of the brightness of walls and ceilings. As a result, some areas could feel gloomy when desktop illuminances were sufficient. Ambient lighting at The Woodland Trust, therefore, included wall-washing (see panel, ‘Woodland Trust: North Atrium’, page 22) 
● The catering kitchen at Heelis used considerably more energy than anticipated. The Woodland Trust decided not to have one 
● The ICT system at Heelis had used more electricity than anticipated. The Woodland Trust, therefore, chose ‘thin clients’ in place of PCs. This – and good use of daylight – also helped to reduce unwanted heat gains into the office space 
● Both server rooms combined chilled water systems with free cooling. However, value engineering at The Woodland Trust changed this from airside to waterside free cooling 
● Both buildings had relatively standard heating systems, with three gas boilers, perimeter trench heating – with a compensated flow temperature – and local zoning, using two-port valves. The Woodland Trust’s plant was more compact and efficient, with lightweight condensing boilers. Heelis had cast-iron boilers, with only one condensing 
● At Heelis, using the heating plant to produce domestic hot water (DHW) proved inefficient in summer, so the post-occupancy evaluation suggested an independent hot water boiler. The designers did not take up this recommendation for The Woodland Trust, as it had more efficient plant, and no catering kitchen.
<h2>
Occupant satisfaction</h2>

Figure 1 compares average scores for headline indicators from the BUS Methodology occupant questionnaire surveys. The satisfaction scales run from 1 (poor, on the left) to 7 (good), apart from the final question – on perceived productivity – which goes from -40% to +40%. The flashes above each of the scales represents the benchmark from the BUS reference dataset for that variable, with the 95% confidence limits. The points are coloured red if they are statistically significantly below the benchmark, green if they are above, and orange if similar. For consistency, BUS 2011 office benchmarks are used for both buildings (2004 benchmarks were originally used for Heelis). The profiles are similar for both buildings. 
 
In detail: 
● Heelis rated worse on winter temperature and summer air quality. This partly related to initial control problems. The situation was improved the following year 
● The lower perceived productivity at Heelis was probably because many staff had relocated from other parts of the country. The Woodland Trust moved just 200 metres 
● Noise at The Woodland Trust was the only indicator significantly worse than average. This reflects a general deterioration in noise perceptions, owing to more open planning, and higher occupation densities. Many Trust staff were also unaccustomed to open-plan offices. In addition, The Woodland Trust needed to use a space that was acoustically connected to the offices for large meetings and training sessions – activities not anticipated in the brief 
● The average score for health at the Trust was linked to less window opening than anticipated, and – perhaps – some initial problems with outgassing. Ventilation control was subsequently improved.
<h2>
Energy performance</h2>

Using standard Building Regulations assumptions, the predicted annual gas consumption was 37.5kWh/m2 GIA at The Woodland Trust. The total in 2012-13 was 32.6kWh/m2, with the heating component, 25.7kWh/m2, almost identical to the design estimate – a very good result in this exceptionally cold year. This also compared well with the 90kWh/m2 for heating and hot water at Heelis, with an additional 24kWh/m2 for its catering kitchen. 
Figure 2 shows annual electricity consumption – in kWh/m2 –for the same period, broken down by end use. Starting at the bottom, this shows: 
 
● The estimated breakdown for Heelis in 2006. Note the large proportion attributable to the server room and catering kitchen. Not shown is its 9kWh/m2 renewable contribution from PV 
● The design estimate for The Woodland Trust, using standard assumptions for Building Regulations, plus Max Fordham’s estimates for the server room 
● In-use performance at the Trust in 2012-13. Note the much lower consumption of the lighting and the ICT in relation to the small power allowance. However, much of this reduction reappeared in the server room and its air-conditioning 
● Potential future savings using relatively lowcost measures – predominantly switching off the VoIP telephones outside office hours (plus associated savings on the switch, UPS and associated air conditioning), and improved control of the backup cooling units in the server room and the ambient lighting. == Issues in operation == Generally, The Woodland Trust building performed well, but some problems arose in use – of which server-room cooling was the most critical. Value engineering at a relatively late stage replaced the independent airside and chilled water cooling systems with a packaged chiller, with both refrigerant and free cooling. Although the chiller was highly specified, it failed every few months, bringing down the Trust’s entire ICT, thin client, and telephone systems. 
The manufacturer was remote and local support proved difficult to obtain, so a basic DX backup system had to be added. The chiller’s controls proved to be vulnerable to brief power interruptions, which are common in Grantham. Although the problems were eventually fixed, simple, more standard equipment would have been preferable. 
Using the boiler plant for both heating and hot water also led to some energy wastage, because of interactions between the two systems. A reduction of nearly 10% in gas consumption was estimated had the systems been completely separated. 
 
The natural ventilation system initially caused problems. In winter, occupants opened windows less than expected because of draughts (the main openings are at desk level). When CO2 levels rose above 1,200ppm, the automated system opened higher-level windows, but the minimum setting of 10% was also draughty. The BMS was eventually altered to give facilities control over minimum window opening. 
 
In summer, night cooling was also disappointing initially, partly because of a complicated control logic and convection currents reaching the external airtemperature sensor when the sun’s rays fell on the building’s timber rain-screen cladding, elevating the detected temperature by as much as 8°C. The situation was improved by relocating the sensor, simplifying the logic, and allowing the facilities manager to decide whether heating or night cooling was required. The function of the concrete radiators was explored in 2012-13, using heat-flux sensing and time-lapse infrared thermography. The average rate of heat absorption during office hours was 5W/m2, rising to 10W/m2 on hot days. An important finding was a need to close windows an hour before the office opened, so temperatures could equilibrate, otherwise the air and furniture could feel too cool when people arrived (see panel ‘Night cooling and concrete radiators’, right.)
<h2>
Conclusions</h2>

The building achieved many of its design objectives: good quality at a normal cost (£1,800/m2), and good levels of occupant satisfaction – though with shortcomings in relation to noise, in particular. Initial problems with air quality and summertime temperature have been tackled, with potential for further fine-tuning. 
Lower energy use than Heelis was achieved for all building-related end uses, especially heating and lighting. However, despite ‘thin clients’ and other efforts, the electricity used by ICT systems was higher. Future projects would benefit from the services of an ICT energy-efficiency consultant. 
 
The ‘keep it simple and do it well’ approach could be taken further still, particularly by improving the usability of control systems, and avoiding over-complication in the name of energy efficiency – especially in the design of the server room cooling system. In terms of procurement, future projects should: 
 
● Adopt soft landings and manage it firmly from the outset, with champions identified 
to carry it forward throughout a project 
● Make better provision for follow-through after practical completion. Fine-tuning will always be necessary – this should be planned for, including a contingency budget to allow any minor alterations to be dealt with quickly and effectively 
● Appreciate the need for constant feedback. With each project there are new things to learn; a problem addressed is not necessarily solved; and unintended consequences may emerge. 
 
References: 
1 The Soft Landings Framework published by BSRIA and UBT in 2009, drew upon this research work, subsequent case studies, and the activities of the user group hosted by BSRIA. Download it from www.usablebuildings.co.uk 
2 G Nevill, So, how are you doing? Building Services, Building Services Journal, 32-37 (November 2007). 
3 The original Probe articles can be downloaded at www.cibse.org/knowledge/probe-post-occupancy-studies 
 
Bill Bordass FCIBSE, of William Bordass Associates and the Usable Buildings Trust, Pete Burgon CEng MCIBSE, of Max Fordham, Hester Brough, of Feilden Clegg Bradley Studios, and Matt Vaudin, of Stonewood Design

For the full article on the CIBSE homepage <a href="http://www.cibsejournal.com">click here</a>.

Performance in use of National Trust’s Heelis building and Woodland Trust’s headquarters

2014-10-02T13:53:38Z

CIBSE:

Performance in use of National Trust’s Heelis building and Woodland Trust’s headquarters

2014-10-02T13:46:31Z

CIBSE:

Article from the October 2014 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Bill Bordass, Pete Burgon, Hester Brough and Matt Vaudin. 

Experience gained from the post-occupancy evaluation of the National Trust’s Heelis building have been fed into the design of The Woodland Trust’s headquarters. The project team compares the in-use performance of both. To maintain the ‘golden thread’ from design intent to reality when creating the 2,727m2 head office for The Woodland Trust, Max Fordham – and architect Feilden Clegg Bradley Studios – used post-occupancy findings from the Heelis = building, in Swindon. The outcomes have now been studied, thanks to funding from Innovate UK – formerly the Technology Strategy Board – and its Building Performance Evaluation programme. In 2002-04, the environmental engineer and architect formed part of a research team investigating the potential for soft landings (1), and discovered the importance of maintaining the ‘golden thread’ – starting with inception and briefing, then managing expectations throughout the procurement process, building on initial aftercare, post-occupancy evaluation, and closing the feedback loop.

== Gathering data ==

At that time, Max Fordham and Feilden Clegg Bradley Studios were working together on Heelis, the National Trust’s 7,605m2 (gross) head office in Swindon. The project followed a strong sustainability agenda, though this was somewhat softened by the requirements of the developer, which procured the building after the scheme design had been agreed with the client. As part of the reality checking advocated by soft landings, a matrix was developed by Feilden Clegg Bradley Studios and Max Fordham, to allow design ambitions for sustainability to be reviewed at project meetings. Max Fordham was also appointed to fine-tune the operation of the mixed-mode building for two years after handover. The Heelis findings were published in Building Services Journal (2) in November 2007. Feilden Clegg Bradley Studios also commissioned William Bordass Associates and Building Use Studies to undertake a postoccupancy review, similar to the Probe studies published in Building Services Journal from 1995-2002 (3).

== Learning from Heelis ==

A key ﬁnding from Heelis was to avoid unmanageable complications. Measures adopted at The Woodland Trust included: ● A traditional contract. The developer-led procurement at Heelis did not allow some elements to evolve as the designers would have preferred ● The steel frame of Heelis had problems with airtightness and thermal bridging. The Woodland Trust, therefore, used a solid, cross-laminated timber (CLT) structure, with external wood-fibre insulation and larch rain-screen cladding. Concrete panels (known as concrete radiators) were also bolted onto the undersides of the CLT floors, to add stiffness and thermal capacity ● Heelis was mixed-mode, with windows that open, automated night ventilation – using motorised inlet panels and the negative pressure roof outlets – and background MVHR in winter. The Woodland Trust used natural ventilation only, with manual windows at desk level and motorised ones at higher level ● Heelis had suspended and recessed ceilingmounted fittings, with occupancy sensing and dimming. The Woodland Trust had a simpler system, with ambient lighting controlled by an area time switch – or from reception – and task lighting by occupants. Corridors, stairs, WCs, and support spaces used self-contained occupancy sensors. Meeting rooms had manual controls ● The design at Heelis optimised daylight factors (see panel, ‘Atrium at Heelis’, right), but took less account of the brightness of walls and ceilings. As a result, some areas could feel gloomy when desktop illuminances were sufficient. Ambient lighting at The Woodland Trust, therefore, included wall-washing (see panel, ‘Woodland Trust: North Atrium’, page 22) ● The catering kitchen at Heelis used considerably more energy than anticipated. The Woodland Trust decided not to have one ● The ICT system at Heelis had used more electricity than anticipated. The Woodland Trust, therefore, chose ‘thin clients’ in place of PCs. This – and good use of daylight – also helped to reduce unwanted heat gains into the office space ● Both server rooms combined chilled water systems with free cooling. However, value engineering at The Woodland Trust changed this from airside to waterside free cooling ● Both buildings had relatively standard heating systems, with three gas boilers, perimeter trench heating – with a compensated flow temperature – and local zoning, using two-port valves. The Woodland Trust’s plant was more compact and efficient, with lightweight condensing boilers. Heelis had cast-iron boilers, with only one condensing ● At Heelis, using the heating plant to produce domestic hot water (DHW) proved inefficient in summer, so the post-occupancy evaluation suggested an independent hot water boiler. The designers did not take up this recommendation for The Woodland Trust, as it had more efficient plant, and no catering kitchen.

== Occupant satisfaction ==

Figure 1 compares average scores for headline indicators from the BUS Methodology occupant questionnaire surveys. The satisfaction scales run from 1 (poor, on the left) to 7 (good), apart from the final question – on perceived productivity – which goes from -40% to +40%. The flashes above each of the scales represents the benchmark from the BUS reference dataset for that variable, with the 95% confidence limits. The points are coloured red if they are statistically significantly below the benchmark, green if they are above, and orange if similar. For consistency, BUS 2011 office benchmarks are used for both buildings (2004 benchmarks were originally used for Heelis). The profiles are similar for both buildings. In detail: ● Heelis rated worse on winter temperature and summer air quality. This partly related to initial control problems. The situation was improved the following year ● The lower perceived productivity at Heelis was probably because many staff had relocated from other parts of the country. The Woodland Trust moved just 200 metres ● Noise at The Woodland Trust was the only indicator significantly worse than average. This reflects a general deterioration in noise perceptions, owing to more open planning, and higher occupation densities. Many Trust staff were also unaccustomed to open-plan offices. In addition, The Woodland Trust needed to use a space that was acoustically connected to the offices for large meetings and training sessions – activities not anticipated in the brief ● The average score for health at the Trust was linked to less window opening than anticipated, and – perhaps – some initial problems with outgassing. Ventilation control was subsequently improved.

== Energy performance ==

Using standard Building Regulations assumptions, the predicted annual gas consumption was 37.5kWh/m2 GIA at The Woodland Trust. The total in 2012-13 was 32.6kWh/m2, with the heating component, 25.7kWh/m2, almost identical to the design estimate – a very good result in this exceptionally cold year. This also compared well with the 90kWh/m2 for heating and hot water at Heelis, with an additional 24kWh/m2 for its catering kitchen. Figure 2 shows annual electricity consumption – in kWh/m2 –for the same period, broken down by end use. Starting at the bottom, this shows: ● The estimated breakdown for Heelis in 2006. Note the large proportion attributable to the server room and catering kitchen. Not shown is its 9kWh/m2 renewable contribution from PV ● The design estimate for The Woodland Trust, using standard assumptions for Building Regulations, plus Max Fordham’s estimates for the server room ● In-use performance at the Trust in 2012-13. Note the much lower consumption of the lighting and the ICT in relation to the small power allowance. However, much of this reduction reappeared in the server room and its air-conditioning ● Potential future savings using relatively lowcost measures – predominantly switching off the VoIP telephones outside office hours (plus associated savings on the switch, UPS and associated air conditioning), and improved control of the backup cooling units in the server room and the ambient lighting.

== Issues in operation ==

Generally, The Woodland Trust building performed well, but some problems arose in use – of which server-room cooling was the most critical. Value engineering at a relatively late stage replaced the independent airside and chilled water cooling systems with a packaged chiller, with both refrigerant and free cooling. Although the chiller was highly specified, it failed every few months, bringing down the Trust’s entire ICT, thin client, and telephone systems. The manufacturer was remote and local support proved difficult to obtain, so a basic DX backup system had to be added. The chiller’s controls proved to be vulnerable to brief power interruptions, which are common in Grantham. Although the problems were eventually fixed, simple, more standard equipment would have been preferable. Using the boiler plant for both heating and hot water also led to some energy wastage, because of interactions between the two systems. A reduction of nearly 10% in gas consumption was estimated had the systems been completely separated. The natural ventilation system initially caused problems. In winter, occupants opened windows less than expected because of draughts (the main openings are at desk level). When CO2 levels rose above 1,200ppm, the automated system opened higher-level windows, but the minimum setting of 10% was also draughty. The BMS was eventually altered to give facilities control over minimum window opening. In summer, night cooling was also disappointing initially, partly because of a complicated control logic and convection currents reaching the external airtemperature sensor when the sun’s rays fell on the building’s timber rain-screen cladding, elevating the detected temperature by as much as 8°C. The situation was improved by relocating the sensor, simplifying the logic, and allowing the facilities manager to decide whether heating or night cooling was required. The function of the concrete radiators was explored in 2012-13, using heat-flux sensing and time-lapse infrared thermography. The average rate of heat absorption during office hours was 5W/m2, rising to 10W/m2 on hot days. An important finding was a need to close windows an hour before the office opened, so temperatures could equilibrate, otherwise the air and furniture could feel too cool when people arrived (see panel ‘Night cooling and concrete radiators’, right.)

== Conclusions ==

The building achieved many of its design objectives: good quality at a normal cost (£1,800/m2), and good levels of occupant satisfaction – though with shortcomings in relation to noise, in particular. Initial problems with air quality and summertime temperature have been tackled, with potential for further fine-tuning. Lower energy use than Heelis was achieved for all building-related end uses, especially heating and lighting. However, despite ‘thin clients’ and other efforts, the electricity used by ICT systems was higher. Future projects would benefit from the services of an ICT energy-efficiency consultant. The ‘keep it simple and do it well’ approach could be taken further still, particularly by improving the usability of control systems, and avoiding over-complication in the name of energy efficiency – especially in the design of the server room cooling system. In terms of procurement, future projects should: ● Adopt soft landings and manage it firmly from the outset, with champions identified to carry it forward throughout a project ● Make better provision for follow-through after practical completion. Fine-tuning will always be necessary – this should be planned for, including a contingency budget to allow any minor alterations to be dealt with quickly and effectively ● Appreciate the need for constant feedback. With each project there are new things to learn; a problem addressed is not necessarily solved; and unintended consequences may emerge. References: 1 The Soft Landings Framework published by BSRIA and UBT in 2009, drew upon this research work, subsequent case studies, and the activities of the user group hosted by BSRIA. Download it from www.usablebuildings.co.uk 2 G Nevill, So, how are you doing? Building Services, Building Services Journal, 32-37 (November 2007). 3 The original Probe articles can be downloaded at www.cibse.org/knowledge/probe-post-occupancy-studies Bill Bordass FCIBSE, of William Bordass Associates and the Usable Buildings Trust, Pete Burgon CEng MCIBSE, of Max Fordham, Hester Brough, of Feilden Clegg Bradley Studios, and Matt Vaudin, of Stonewood Design

For the full article please follow the link [[www.cibsejournal.com|www.cibsejournal.com]]

Performance in use of National Trust’s Heelis building and Woodland Trust’s headquarters

2014-10-02T13:43:24Z

CIBSE:

Experience gained from the post-occupancy evaluation of the National Trust’s Heelis building have been fed into the design of The Woodland Trust’s headquarters. The project team compares the in-use performance of both. To maintain the ‘golden thread’ from design intent to reality when creating the 2,727m2 head office for The Woodland Trust, Max Fordham – and architect Feilden Clegg Bradley Studios – used post-occupancy findings from the Heelis = building, in Swindon. The outcomes have now been studied, thanks to funding from Innovate UK – formerly the Technology Strategy Board – and its Building Performance Evaluation programme. In 2002-04, the environmental engineer and architect formed part of a research team investigating the potential for soft landings (1), and discovered the importance of maintaining the ‘golden thread’ – starting with inception and briefing, then managing expectations throughout the procurement process, building on initial aftercare, post-occupancy evaluation, and closing the feedback loop.

== Gathering data ==

At that time, Max Fordham and Feilden Clegg Bradley Studios were working together on Heelis, the National Trust’s 7,605m2 (gross) head office in Swindon. The project followed a strong sustainability agenda, though this was somewhat softened by the requirements of the developer, which procured the building after the scheme design had been agreed with the client. As part of the reality checking advocated by soft landings, a matrix was developed by Feilden Clegg Bradley Studios and Max Fordham, to allow design ambitions for sustainability to be reviewed at project meetings. Max Fordham was also appointed to fine-tune the operation of the mixed-mode building for two years after handover. The Heelis findings were published in Building Services Journal (2) in November 2007. Feilden Clegg Bradley Studios also commissioned William Bordass Associates and Building Use Studies to undertake a postoccupancy review, similar to the Probe studies published in Building Services Journal from 1995-2002 (3).

== Learning from Heelis ==

A key ﬁnding from Heelis was to avoid unmanageable complications. Measures adopted at The Woodland Trust included: ● A traditional contract. The developer-led procurement at Heelis did not allow some elements to evolve as the designers would have preferred ● The steel frame of Heelis had problems with airtightness and thermal bridging. The Woodland Trust, therefore, used a solid, cross-laminated timber (CLT) structure, with external wood-fibre insulation and larch rain-screen cladding. Concrete panels (known as concrete radiators) were also bolted onto the undersides of the CLT floors, to add stiffness and thermal capacity ● Heelis was mixed-mode, with windows that open, automated night ventilation – using motorised inlet panels and the negative pressure roof outlets – and background MVHR in winter. The Woodland Trust used natural ventilation only, with manual windows at desk level and motorised ones at higher level ● Heelis had suspended and recessed ceilingmounted fittings, with occupancy sensing and dimming. The Woodland Trust had a simpler system, with ambient lighting controlled by an area time switch – or from reception – and task lighting by occupants. Corridors, stairs, WCs, and support spaces used self-contained occupancy sensors. Meeting rooms had manual controls ● The design at Heelis optimised daylight factors (see panel, ‘Atrium at Heelis’, right), but took less account of the brightness of walls and ceilings. As a result, some areas could feel gloomy when desktop illuminances were sufficient. Ambient lighting at The Woodland Trust, therefore, included wall-washing (see panel, ‘Woodland Trust: North Atrium’, page 22) ● The catering kitchen at Heelis used considerably more energy than anticipated. The Woodland Trust decided not to have one ● The ICT system at Heelis had used more electricity than anticipated. The Woodland Trust, therefore, chose ‘thin clients’ in place of PCs. This – and good use of daylight – also helped to reduce unwanted heat gains into the office space ● Both server rooms combined chilled water systems with free cooling. However, value engineering at The Woodland Trust changed this from airside to waterside free cooling ● Both buildings had relatively standard heating systems, with three gas boilers, perimeter trench heating – with a compensated flow temperature – and local zoning, using two-port valves. The Woodland Trust’s plant was more compact and efficient, with lightweight condensing boilers. Heelis had cast-iron boilers, with only one condensing ● At Heelis, using the heating plant to produce domestic hot water (DHW) proved inefficient in summer, so the post-occupancy evaluation suggested an independent hot water boiler. The designers did not take up this recommendation for The Woodland Trust, as it had more efficient plant, and no catering kitchen.

== Occupant satisfaction ==

Figure 1 compares average scores for headline indicators from the BUS Methodology occupant questionnaire surveys. The satisfaction scales run from 1 (poor, on the left) to 7 (good), apart from the final question – on perceived productivity – which goes from -40% to +40%. The flashes above each of the scales represents the benchmark from the BUS reference dataset for that variable, with the 95% confidence limits. The points are coloured red if they are statistically significantly below the benchmark, green if they are above, and orange if similar. For consistency, BUS 2011 office benchmarks are used for both buildings (2004 benchmarks were originally used for Heelis). The profiles are similar for both buildings. In detail: ● Heelis rated worse on winter temperature and summer air quality. This partly related to initial control problems. The situation was improved the following year ● The lower perceived productivity at Heelis was probably because many staff had relocated from other parts of the country. The Woodland Trust moved just 200 metres ● Noise at The Woodland Trust was the only indicator significantly worse than average. This reflects a general deterioration in noise perceptions, owing to more open planning, and higher occupation densities. Many Trust staff were also unaccustomed to open-plan offices. In addition, The Woodland Trust needed to use a space that was acoustically connected to the offices for large meetings and training sessions – activities not anticipated in the brief ● The average score for health at the Trust was linked to less window opening than anticipated, and – perhaps – some initial problems with outgassing. Ventilation control was subsequently improved.

== Energy performance ==

Using standard Building Regulations assumptions, the predicted annual gas consumption was 37.5kWh/m2 GIA at The Woodland Trust. The total in 2012-13 was 32.6kWh/m2, with the heating component, 25.7kWh/m2, almost identical to the design estimate – a very good result in this exceptionally cold year. This also compared well with the 90kWh/m2 for heating and hot water at Heelis, with an additional 24kWh/m2 for its catering kitchen. Figure 2 shows annual electricity consumption – in kWh/m2 –for the same period, broken down by end use. Starting at the bottom, this shows: ● The estimated breakdown for Heelis in 2006. Note the large proportion attributable to the server room and catering kitchen. Not shown is its 9kWh/m2 renewable contribution from PV ● The design estimate for The Woodland Trust, using standard assumptions for Building Regulations, plus Max Fordham’s estimates for the server room ● In-use performance at the Trust in 2012-13. Note the much lower consumption of the lighting and the ICT in relation to the small power allowance. However, much of this reduction reappeared in the server room and its air-conditioning ● Potential future savings using relatively lowcost measures – predominantly switching off the VoIP telephones outside office hours (plus associated savings on the switch, UPS and associated air conditioning), and improved control of the backup cooling units in the server room and the ambient lighting.

== Issues in operation ==

Generally, The Woodland Trust building performed well, but some problems arose in use – of which server-room cooling was the most critical. Value engineering at a relatively late stage replaced the independent airside and chilled water cooling systems with a packaged chiller, with both refrigerant and free cooling. Although the chiller was highly specified, it failed every few months, bringing down the Trust’s entire ICT, thin client, and telephone systems. The manufacturer was remote and local support proved difficult to obtain, so a basic DX backup system had to be added. The chiller’s controls proved to be vulnerable to brief power interruptions, which are common in Grantham. Although the problems were eventually fixed, simple, more standard equipment would have been preferable. Using the boiler plant for both heating and hot water also led to some energy wastage, because of interactions between the two systems. A reduction of nearly 10% in gas consumption was estimated had the systems been completely separated. The natural ventilation system initially caused problems. In winter, occupants opened windows less than expected because of draughts (the main openings are at desk level). When CO2 levels rose above 1,200ppm, the automated system opened higher-level windows, but the minimum setting of 10% was also draughty. The BMS was eventually altered to give facilities control over minimum window opening. In summer, night cooling was also disappointing initially, partly because of a complicated control logic and convection currents reaching the external airtemperature sensor when the sun’s rays fell on the building’s timber rain-screen cladding, elevating the detected temperature by as much as 8°C. The situation was improved by relocating the sensor, simplifying the logic, and allowing the facilities manager to decide whether heating or night cooling was required. The function of the concrete radiators was explored in 2012-13, using heat-flux sensing and time-lapse infrared thermography. The average rate of heat absorption during office hours was 5W/m2, rising to 10W/m2 on hot days. An important finding was a need to close windows an hour before the office opened, so temperatures could equilibrate, otherwise the air and furniture could feel too cool when people arrived (see panel ‘Night cooling and concrete radiators’, right.)

== Conclusions ==

The building achieved many of its design objectives: good quality at a normal cost (£1,800/m2), and good levels of occupant satisfaction – though with shortcomings in relation to noise, in particular. Initial problems with air quality and summertime temperature have been tackled, with potential for further fine-tuning. Lower energy use than Heelis was achieved for all building-related end uses, especially heating and lighting. However, despite ‘thin clients’ and other efforts, the electricity used by ICT systems was higher. Future projects would benefit from the services of an ICT energy-efficiency consultant. The ‘keep it simple and do it well’ approach could be taken further still, particularly by improving the usability of control systems, and avoiding over-complication in the name of energy efficiency – especially in the design of the server room cooling system. In terms of procurement, future projects should: ● Adopt soft landings and manage it firmly from the outset, with champions identified to carry it forward throughout a project ● Make better provision for follow-through after practical completion. Fine-tuning will always be necessary – this should be planned for, including a contingency budget to allow any minor alterations to be dealt with quickly and effectively ● Appreciate the need for constant feedback. With each project there are new things to learn; a problem addressed is not necessarily solved; and unintended consequences may emerge. References: 1 The Soft Landings Framework published by BSRIA and UBT in 2009, drew upon this research work, subsequent case studies, and the activities of the user group hosted by BSRIA. Download it from www.usablebuildings.co.uk 2 G Nevill, So, how are you doing? Building Services, Building Services Journal, 32-37 (November 2007). 3 The original Probe articles can be downloaded at www.cibse.org/knowledge/probe-post-occupancy-studies Bill Bordass FCIBSE, of William Bordass Associates and the Usable Buildings Trust, Pete Burgon CEng MCIBSE, of Max Fordham, Hester Brough, of Feilden Clegg Bradley Studios, and Matt Vaudin, of Stonewood Design

For the full article please follow the link www.cibsejournal.com

Performance in use of National Trust’s Heelis building and Woodland Trust’s headquarters

2014-10-02T13:42:35Z

CIBSE: Created page with " Experience gained from the post-occupancy evaluation of the National Trust’s Heelis building have been fed into the design of The Woodland Trust’s headquarters. The project..."

Experience gained from the post-occupancy evaluation of the National Trust’s Heelis building have been fed into the design of The Woodland Trust’s headquarters. The project team compares the in-use performance of both. To maintain the ‘golden thread’ from design intent to reality when creating the 2,727m2 head office for The Woodland Trust, Max Fordham – and architect Feilden Clegg Bradley Studios – used post-occupancy findings from the Heelis = building, in Swindon. The outcomes have now been studied, thanks to funding from Innovate UK – formerly the Technology Strategy Board – and its Building Performance Evaluation programme. In 2002-04, the environmental engineer and architect formed part of a research team investigating the potential for soft landings (1), and discovered the importance of maintaining the ‘golden thread’ – starting with inception and briefing, then managing expectations throughout the procurement process, building on initial aftercare, post-occupancy evaluation, and closing the feedback loop.

== Gathering data ==

At that time, Max Fordham and Feilden Clegg Bradley Studios were working together on Heelis, the National Trust’s 7,605m2 (gross) head office in Swindon. The project followed a strong sustainability agenda, though this was somewhat softened by the requirements of the developer, which procured the building after the scheme design had been agreed with the client. As part of the reality checking advocated by soft landings, a matrix was developed by Feilden Clegg Bradley Studios and Max Fordham, to allow design ambitions for sustainability to be reviewed at project meetings. Max Fordham was also appointed to fine-tune the operation of the mixed-mode building for two years after handover. The Heelis findings were published in Building Services Journal (2) in November 2007. Feilden Clegg Bradley Studios also commissioned William Bordass Associates and Building Use Studies to undertake a postoccupancy review, similar to the Probe studies published in Building Services Journal from 1995-2002 (3).

== <a name="Learning "></a>Learning from Heelis ==

A key ﬁnding from Heelis was to avoid unmanageable complications. Measures adopted at The Woodland Trust included: ● A traditional contract. The developer-led procurement at Heelis did not allow some elements to evolve as the designers would have preferred ● The steel frame of Heelis had problems with airtightness and thermal bridging. The Woodland Trust, therefore, used a solid, cross-laminated timber (CLT) structure, with external wood-fibre insulation and larch rain-screen cladding. Concrete panels (known as concrete radiators) were also bolted onto the undersides of the CLT floors, to add stiffness and thermal capacity ● Heelis was mixed-mode, with windows that open, automated night ventilation – using motorised inlet panels and the negative pressure roof outlets – and background MVHR in winter. The Woodland Trust used natural ventilation only, with manual windows at desk level and motorised ones at higher level ● Heelis had suspended and recessed ceilingmounted fittings, with occupancy sensing and dimming. The Woodland Trust had a simpler system, with ambient lighting controlled by an area time switch – or from reception – and task lighting by occupants. Corridors, stairs, WCs, and support spaces used self-contained occupancy sensors. Meeting rooms had manual controls ● The design at Heelis optimised daylight factors (see panel, ‘Atrium at Heelis’, right), but took less account of the brightness of walls and ceilings. As a result, some areas could feel gloomy when desktop illuminances were sufficient. Ambient lighting at The Woodland Trust, therefore, included wall-washing (see panel, ‘Woodland Trust: North Atrium’, page 22) ● The catering kitchen at Heelis used considerably more energy than anticipated. The Woodland Trust decided not to have one ● The ICT system at Heelis had used more electricity than anticipated. The Woodland Trust, therefore, chose ‘thin clients’ in place of PCs. This – and good use of daylight – also helped to reduce unwanted heat gains into the office space ● Both server rooms combined chilled water systems with free cooling. However, value engineering at The Woodland Trust changed this from airside to waterside free cooling ● Both buildings had relatively standard heating systems, with three gas boilers, perimeter trench heating – with a compensated flow temperature – and local zoning, using two-port valves. The Woodland Trust’s plant was more compact and efficient, with lightweight condensing boilers. Heelis had cast-iron boilers, with only one condensing ● At Heelis, using the heating plant to produce domestic hot water (DHW) proved inefficient in summer, so the post-occupancy evaluation suggested an independent hot water boiler. The designers did not take up this recommendation for The Woodland Trust, as it had more efficient plant, and no catering kitchen.

== Occupant satisfaction ==

Figure 1 compares average scores for headline indicators from the BUS Methodology occupant questionnaire surveys. The satisfaction scales run from 1 (poor, on the left) to 7 (good), apart from the final question – on perceived productivity – which goes from -40% to +40%. The flashes above each of the scales represents the benchmark from the BUS reference dataset for that variable, with the 95% confidence limits. The points are coloured red if they are statistically significantly below the benchmark, green if they are above, and orange if similar. For consistency, BUS 2011 office benchmarks are used for both buildings (2004 benchmarks were originally used for Heelis). The profiles are similar for both buildings. In detail: ● Heelis rated worse on winter temperature and summer air quality. This partly related to initial control problems. The situation was improved the following year ● The lower perceived productivity at Heelis was probably because many staff had relocated from other parts of the country. The Woodland Trust moved just 200 metres ● Noise at The Woodland Trust was the only indicator significantly worse than average. This reflects a general deterioration in noise perceptions, owing to more open planning, and higher occupation densities. Many Trust staff were also unaccustomed to open-plan offices. In addition, The Woodland Trust needed to use a space that was acoustically connected to the offices for large meetings and training sessions – activities not anticipated in the brief ● The average score for health at the Trust was linked to less window opening than anticipated, and – perhaps – some initial problems with outgassing. Ventilation control was subsequently improved.

== Energy performance ==

Using standard Building Regulations assumptions, the predicted annual gas consumption was 37.5kWh/m2 GIA at The Woodland Trust. The total in 2012-13 was 32.6kWh/m2, with the heating component, 25.7kWh/m2, almost identical to the design estimate – a very good result in this exceptionally cold year. This also compared well with the 90kWh/m2 for heating and hot water at Heelis, with an additional 24kWh/m2 for its catering kitchen. Figure 2 shows annual electricity consumption – in kWh/m2 –for the same period, broken down by end use. Starting at the bottom, this shows: ● The estimated breakdown for Heelis in 2006. Note the large proportion attributable to the server room and catering kitchen. Not shown is its 9kWh/m2 renewable contribution from PV ● The design estimate for The Woodland Trust, using standard assumptions for Building Regulations, plus Max Fordham’s estimates for the server room ● In-use performance at the Trust in 2012-13. Note the much lower consumption of the lighting and the ICT in relation to the small power allowance. However, much of this reduction reappeared in the server room and its air-conditioning ● Potential future savings using relatively lowcost measures – predominantly switching off the VoIP telephones outside office hours (plus associated savings on the switch, UPS and associated air conditioning), and improved control of the backup cooling units in the server room and the ambient lighting.

== Issues in operation ==

Generally, The Woodland Trust building performed well, but some problems arose in use – of which server-room cooling was the most critical. Value engineering at a relatively late stage replaced the independent airside and chilled water cooling systems with a packaged chiller, with both refrigerant and free cooling. Although the chiller was highly specified, it failed every few months, bringing down the Trust’s entire ICT, thin client, and telephone systems. The manufacturer was remote and local support proved difficult to obtain, so a basic DX backup system had to be added. The chiller’s controls proved to be vulnerable to brief power interruptions, which are common in Grantham. Although the problems were eventually fixed, simple, more standard equipment would have been preferable. Using the boiler plant for both heating and hot water also led to some energy wastage, because of interactions between the two systems. A reduction of nearly 10% in gas consumption was estimated had the systems been completely separated. The natural ventilation system initially caused problems. In winter, occupants opened windows less than expected because of draughts (the main openings are at desk level). When CO2 levels rose above 1,200ppm, the automated system opened higher-level windows, but the minimum setting of 10% was also draughty. The BMS was eventually altered to give facilities control over minimum window opening. In summer, night cooling was also disappointing initially, partly because of a complicated control logic and convection currents reaching the external airtemperature sensor when the sun’s rays fell on the building’s timber rain-screen cladding, elevating the detected temperature by as much as 8°C. The situation was improved by relocating the sensor, simplifying the logic, and allowing the facilities manager to decide whether heating or night cooling was required. The function of the concrete radiators was explored in 2012-13, using heat-flux sensing and time-lapse infrared thermography. The average rate of heat absorption during office hours was 5W/m2, rising to 10W/m2 on hot days. An important finding was a need to close windows an hour before the office opened, so temperatures could equilibrate, otherwise the air and furniture could feel too cool when people arrived (see panel ‘Night cooling and concrete radiators’, right.)

== Conclusions ==

The building achieved many of its design objectives: good quality at a normal cost (£1,800/m2), and good levels of occupant satisfaction – though with shortcomings in relation to noise, in particular. Initial problems with air quality and summertime temperature have been tackled, with potential for further fine-tuning. Lower energy use than Heelis was achieved for all building-related end uses, especially heating and lighting. However, despite ‘thin clients’ and other efforts, the electricity used by ICT systems was higher. Future projects would benefit from the services of an ICT energy-efficiency consultant. The ‘keep it simple and do it well’ approach could be taken further still, particularly by improving the usability of control systems, and avoiding over-complication in the name of energy efficiency – especially in the design of the server room cooling system. In terms of procurement, future projects should: ● Adopt soft landings and manage it firmly from the outset, with champions identified to carry it forward throughout a project ● Make better provision for follow-through after practical completion. Fine-tuning will always be necessary – this should be planned for, including a contingency budget to allow any minor alterations to be dealt with quickly and effectively ● Appreciate the need for constant feedback. With each project there are new things to learn; a problem addressed is not necessarily solved; and unintended consequences may emerge. References: 1 The Soft Landings Framework published by BSRIA and UBT in 2009, drew upon this research work, subsequent case studies, and the activities of the user group hosted by BSRIA. Download it from www.usablebuildings.co.uk 2 G Nevill, So, how are you doing? Building Services, Building Services Journal, 32-37 (November 2007). 3 The original Probe articles can be downloaded at www.cibse.org/knowledge/probe-post-occupancy-studies Bill Bordass FCIBSE, of William Bordass Associates and the Usable Buildings Trust, Pete Burgon CEng MCIBSE, of Max Fordham, Hester Brough, of Feilden Clegg Bradley Studios, and Matt Vaudin, of Stonewood Design

For the full article please follow the link www.cibsejournal.com

CIBSE Case Study Ortus Learning and Events Centre

2014-09-10T10:49:35Z

CIBSE:

''Article from the August 2014 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Alex Smith.''

The Ortus learning and events centre is an uplifting addition to the Maudsley hospital estate that benefits from a collaborative approach to design. In recent years health experts have identified five factors associated with mental wellbeing: connecting with others; learning; giving; being active; and taking notice were identified as the elements key to good mental health by the New Economics Foundation in 2008. Now there’s a building that reflects these findings. The Ortus learning and events centre in Camberwell, South London, is a light-filled cube that invites the public to share space and resources with academics, doctors and patients on the Maudsley mental health campus. The £6m event and conference building, sponsored by the Maudsley charity, is designed to be an uplifting, welcoming space that is open to all. It’s the antithesis of the fortified Victorian asylums that were closed after the NHS moved from institutional to community care 30 years ago. ‘It’s got the Festival Hall factor,’ says Ken Cowdery, the client representative from Articulate. ‘Everyone is welcome. There are no barriers or security guards at the entrance. You can’t tell who’s a doctor, a visitor, a patient, or the local who’s come in for a cup of coffee. It’s changing the perception of what mental health is.’ Designing such an open, collaborative building presented the building services consultant, Skelly and Couch, with some tough design challenges, particularly around acoustics, thermal comfort and daylighting. The Maudsley wanted large, open spaces that could also function as intimate, contemplative spaces when required. The challenge was amplified by the decision to pursue a natural ventilation strategy as far as possible and to flood the building’s core with daylight – Skelly and Couch had to devise a strategy allowing the free flow of air and penetration of daylight, while blocking noise. Fortunately, the consultant was able to influence the design at an early stage by engaging with the architects at building inception and then working closely with the trade contractors, thanks to the use of PPC2000 procurement. This awards projects to trade contractors on the basis of an outline brief and cost benchmark, and allows them to work collaboratively with design teams to an agreed budget. The result was that everyone on the design and construction team – from architect to contractor to M&E specialists – shared the client’s vision for the building and were able to feed their expertise into the designs.

== Opening doors ==

The Ortus learning and events centre is the home of Maudsley Learning whose mission is to ‘support and provide world class and accessible learning in mental health and wellbeing.’ Together with Ortus Online, Maudsley Learning aims to reach a local and world wide audience. The charity’s vision of an open, engaging building is refl ected in its design, which is arranged over seven half-levels on a sloping site. Daylight fl oods in via windows and rooflights into a central atrium, where people are encouraged to meet and relax on the main staircase and half landings. The café has been placed at the entrance to tempt passersby inside, while wooden fl oors, exposed brick walls and burgundy drapes give the environment a warmth not usually associated with hospital estate buildings. As well as a large conference space, there are also smaller meeting rooms, offices and a terrace on the roof with uninterrupted views towards central London. The requirement for an open, connected building helped drive the services strategy, according to Skelly and Couch director Mark Maidment. ‘The Maudsley’s philosophy works for us,’ he says. ‘We pursued a passive first “aircon light” strategy and its open form aids natural ventilation.’ Engagement with the architect at inception meant that Skelly and Couch were able to drive the form of the building at an early design stage. The consultant was responsible for positioning the building away from other structures on the estate to maximise daylight. It used the sloping topography of the site to step the structure and create half levels that give a sense of openness in the atrium and allow sunlight to penetrate deep into the plan (see diagram on page 31). Skelly and Couch minimised the need for mechanical plant, by utilising the passive stack ventilation effect in the atrium (which also doubles up as a theatre space on the ground floor). Fresh air enters the building through automated and manual windows, before passing up through an atrium and out of the building via louvres in the roof (see diagram on page 31). In the main conference rooms, which can accommodate 120 people seated, the raised flooring acts as a supply plenum. Fans can be turned on to encourage the movement of air, and cooled, if required, by a closed loop ground source heat pump (GSHP) consisting of 120m vertical loops and a heat/cool pump. An open loop system utilising the ‘Camberwell’ was considered, but the site’s position at the top of a hill made the option unfeasible. A 71m2 PV array on the roof (44 panels measuring 1.6m x 1m offering 10kW peak) helps power the GSHP, and saves at least 4 tonnes of carbon dioxide each year. While only the conference room is mechanically cooled (when occupied), every room – the cafe being the only exception – has underfloor heating. Exposed concrete soffits are a key component of the ‘aircon light’ strategy. The thermal mass provides cooling, and Skelly and Couch were able to increase the area of effective thermal mass by using a ribbed design that increased the surface area of the exposed concrete. The success of the ventilation strategy depended on air being able to flow between separate rooms. To stop noise interference between connected spaces, cross talk attenuators were used, which allowed acoustic privacy without inhibiting air flow. For Skelly and Couch’s low energy design strategy to be realised in the operation of the building, design details and installation had to be of a high quality. For example, the envelope needed to have very good airtightness and the supply plenum in the conference room had to be well sealed. Maidment says the two stage open book procurement method enabled consultants and subcontractors to speak to each other and ensure a high quality installation. ‘Often there’s a main contractor in the middle who doesn’t understand what we’re doing, and they make the decisions.’ Maidment says the airtightness of the façade was dependent on quality workmanship. ‘It was about making subcontractors understand why they’ve got to do things in a certain way. If they know why they are doing it they are more likely to do it properly,’ he says. Another area where close collaboration between subcontractors was crucial was in the underfloor heating, where the heating elements had to be in close contact with the metal plates, in order for the floor to radiate heat. Discussions between the base floor contractor and mechanical engineer ensured a good result.

== One year on ==

Ortus has now been in operation over one winter and summer. Maidment says the GSHP has worked well during that time achieving a COP of 3.8, slightly better than expected. The COP was calculated by measuring the complete electrical demand including all circulation pumps, an element that often gets missed says Maidment. Skelly and Couch has been monitoring energy during the defects period, and may be employed on a soft landings strategy when this comes to an end. During that time it has worked with the control contractor to come up with winter and summer settings. ‘The settings are very different,’ says Maidment. The period when you go from winter to summer is quite short, which I was surprised by. As soon as you have a few hot days you need to change over. Maidment says it has taken a little while to get the meters to read properly, but says figures from the spring and summer were looking very good and approaching the design figures. ‘We are looking at huge savings on the artificial light because the building is very well daylit, and as we move into the summer we are seeing the benefits of the passive cooling strategy.’ The open book partnering agreement meant that everyone knew what budget was being worked to, so if any element was coming in over budget, design teams looked at how they could value engineer costs elsewhere. As a result the project came in ‘on budget, on time, and on quality,’ according to Cowdery and the Maudsley now has a world-class building to match its reputation.

== Project Team ==
*Client: Maudsley Charity
*MEP, acoustic and environmental consultant: Skelly and Couch
*Client representative: Articulate
*Architect: Duggan Morris Architects
*Construction manager: Cavendish Berkeley
*Structural engineer: Elliott Wood
*Cost consultant: Measur
*Mechanical contractor: Elmstead Mechanical
*Electrical contractor: Livewire
*Controls specialist: AIS

== In control ==

By combining the lighting and HVAC controls on one network, Skelly and Couch were able to cut control costs by 40%. The controls specialist AIS suggested combining the controls using the wellestablished KNX protocol, which meant that lighting and HVAC could share field wire and the control system. Temperatures, lighting, and windows can all be controlled from a single control panel in each room (right), so avoiding the clutter of multiple wall panels. A lot of thought went into the design of the control panels. ‘People are often intimidated by controls and don’t understand them, but they don’t like to say in case they appear stupid,’ says Maidment. ‘The person managing the building has no building services experience so we had to make sure the systems were understood.’ 

To read the full article on the CIBSE homepage please [[Www.cibsejournal.com|click here]].

CIBSE Case Study Ortus Learning and Events Centre

2014-09-10T10:44:41Z

CIBSE: Created page with " ''Article from the August 2014 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Alex Smith.'' The Ortus learning and events centre is an uplifting ..."

''Article from the August 2014 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Alex Smith.'' 

The Ortus learning and events centre is an uplifting addition to the Maudsley hospital estate that benefits from a collaborative approach to design. In recent years health experts have identified five factors associated with mental wellbeing: connecting with others; learning; giving; being active; and taking notice were identified as the elements key to good mental health by the New Economics Foundation in 2008. Now there’s a building that reflects these findings. The Ortus learning

and events centre in Camberwell, South London, is a light-filled cube

that invites the public to share space and resources with academics, doctors and patients on the Maudsley mental health campus. The £6m event and conference building, sponsored by the Maudsley charity, is designed to be an uplifting, welcoming space that is open to all. It’s the antithesis of the fortified Victorian asylums that were closed after the NHS moved from institutional to community care 30 years ago. ‘It’s got the Festival Hall factor,’ says Ken Cowdery, the client representative from Articulate. ‘Everyone is welcome. There are no barriers or security guards at the entrance. You can’t tell who’s a doctor, a visitor, a patient, or the local who’s come in for a cup of coffee. It’s changing the perception of what mental health is.’ Designing such an open, collaborative building presented the building services consultant, Skelly and Couch, with some tough design challenges, particularly around acoustics, thermal comfort and daylighting. The Maudsley wanted large, open spaces that could also function as intimate, contemplative spaces when required. The challenge was amplified by the decision to pursue a natural ventilation strategy as far as possible and to flood the building’s core with daylight – Skelly and Couch had to devise a strategy allowing the free flow of air and penetration of daylight, while blocking noise. Fortunately, the consultant was able to influence the design at an early stage by engaging with the architects at building inception and then working closely with the trade contractors, thanks to the use of PPC2000 procurement. This awards projects to trade contractors on the basis of an outline brief and cost benchmark, and allows them to work collaboratively with design teams to an agreed budget. The result was that everyone on the design and construction team – from architect to contractor to M&E specialists – shared the client’s vision for the building and were able to feed their expertise into the designs.

== Opening doors ==

The Ortus learning and events centre is the home of Maudsley Learning whose mission is to ‘support and provide world class and accessible learning in mental health and wellbeing.’ Together with Ortus Online, Maudsley Learning aims to reach a local and world wide audience. The charity’s vision of an open, engaging building is refl ected in its design, which is arranged over seven half-levels on a sloping site. Daylight fl oods in via windows and rooflights into a central atrium, where people are encouraged to meet and relax on the main staircase and half landings. The café has been placed at the entrance to tempt passersby inside, while wooden fl oors, exposed brick walls and burgundy drapes give the environment a warmth not usually associated with hospital estate buildings. As well as a large conference space, there are also smaller meeting rooms, offices and a terrace on the roof with uninterrupted views towards central London. The requirement for an open, connected building helped drive the services strategy, according to Skelly and Couch director Mark Maidment. ‘The Maudsley’s philosophy works for us,’ he says. ‘We pursued a passive first “aircon light” strategy and its open form aids natural ventilation.’ Engagement with the architect at inception meant that Skelly and Couch were able to drive the form of the building at an early design stage. The consultant was responsible for positioning the building away from other structures on the estate to maximise daylight. It used the sloping topography of the site to step the structure and create half levels that give a sense of openness in the atrium and allow sunlight to penetrate deep into the plan (see diagram on page 31). Skelly and Couch minimised the need for mechanical plant, by utilising the passive stack ventilation effect in the atrium (which also doubles up as a theatre space on the ground floor). Fresh air enters the building through automated and manual windows, before passing up through an atrium and out of the building via louvres in the roof (see diagram on page 31). In the main conference rooms, which can accommodate 120 people seated, the raised flooring acts as a supply plenum. Fans can be turned on to encourage the movement of air, and cooled, if required, by a closed loop ground source heat pump (GSHP) consisting of 120m vertical loops and a heat/cool pump. An open loop system utilising the ‘Camberwell’ was considered, but the site’s position at the top of a hill made the option unfeasible. A 71m2 PV array on the roof (44 panels measuring 1.6m x 1m offering 10kW peak) helps power the GSHP, and saves at least 4 tonnes of carbon dioxide each year. While only the conference room is mechanically cooled (when occupied), every room – the cafe being the only exception – has underfloor heating. Exposed concrete soffits are a key component of the ‘aircon light’ strategy. The thermal mass provides cooling, and Skelly and Couch were able to increase the area of effective thermal mass by using a ribbed design that increased the surface area of the exposed concrete. The success of the ventilation strategy depended on air being able to flow between separate rooms. To stop noise interference between connected spaces, cross talk attenuators were used, which allowed acoustic privacy without inhibiting air flow. For Skelly and Couch’s low energy design strategy to be realised in the operation of the building, design details and installation had to be of a high quality. For example, the envelope needed to have very good airtightness and the supply plenum in the conference room had to be well sealed. Maidment says the two stage open book procurement method enabled consultants and subcontractors to speak to each other and ensure a high quality installation. ‘Often there’s a main contractor in the middle who doesn’t understand what we’re doing, and they make the decisions.’ Maidment says the airtightness of the façade was dependent on quality workmanship. ‘It was about making subcontractors understand why they’ve got to do things in a certain way. If they know why they are doing it they are more likely to do it properly,’ he says. Another area where close collaboration between subcontractors was crucial was in the underfloor heating, where the heating elements had to be in close contact with the metal plates, in order for the floor to radiate heat. Discussions between the base floor contractor and mechanical engineer ensured a good result.

== One year on ==

Ortus has now been in operation over one winter and summer. Maidment says the GSHP has worked well during that time achieving a COP of 3.8, slightly better than expected. The COP was calculated by measuring the complete electrical demand including all circulation pumps, an element that often gets missed says Maidment. Skelly and Couch has been monitoring energy during the defects period, and may be employed on a soft landings strategy when this comes to an end. During that time it has worked with the control contractor to come up with winter and summer settings. ‘The settings are very different,’ says Maidment. The period when you go from winter to summer is quite short, which I was surprised by. As soon as you have a few hot days you need to change over. Maidment says it has taken a little while to get the meters to read properly, but says figures from the spring and summer were looking very good and approaching the design figures. ‘We are looking at huge savings on the artificial light because the building is very well daylit, and as we move into the summer we are seeing the benefits of the passive cooling strategy.’ The open book partnering agreement meant that everyone knew what budget was being worked to, so if any element was coming in over budget, design teams looked at how they could value engineer costs elsewhere. As a result the project came in ‘on budget, on time, and on quality,’ according to Cowdery and the Maudsley now has a world-class building to match its reputation.

== Project Team ==
*Client: Maudsley Charity
*MEP, acoustic and environmental consultant: Skelly and Couch
*Client representative: Articulate
*Architect: Duggan Morris Architects
*Construction manager: Cavendish Berkeley
*Structural engineer: Elliott Wood
*Cost consultant: Measur
*Mechanical contractor: Elmstead Mechanical
*Electrical contractor: Livewire
*Controls specialist: AIS

== In control ==

By combining the lighting and HVAC controls on one network, Skelly and Couch were able to cut control costs by 40%. The controls specialist AIS suggested combining the controls using the wellestablished KNX protocol, which meant that lighting and HVAC could share field wire and the control system. Temperatures, lighting, and windows can all be controlled from a single control panel in each room (right), so avoiding the clutter of multiple wall panels. A lot of thought went into the design of the control panels. ‘People are often intimidated by controls and don’t understand them, but they don’t like to say in case they appear stupid,’ says Maidment. ‘The person managing the building has no building services experience so we had to make sure the systems were understood.’ 

To read the full article on the CIBSE homepage please [[www.cibsejournal.com|click here]].

CIBSE Case Study Francis Crick Institute

2014-09-10T10:23:36Z

CIBSE:

''Article from the September 2014 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Steve Berry.''

One of the world’s largest biomedical research centres is nearing completion in a heavily built-up district of central London. 1953, Francis Crick – together with his colleagues James Watson and Maurice Wilkins – identified the structure of DNA . This proved to be of significant importance to biomedical research, and earned Crick, Watson and Wilkins the 1962 Nobel Prize in Physiology or Medicine. In 2015, the institute that bears his name will open its doors to the scientific community. Located opposite London’s St Pancras Station it will be an entirely new organisation, with a distinctive vision of how medical research should be conducted. This involves bringing the best minds together and engaging in extensive collaboration between scientists, biologists, chemists and physicists, with the aim of discovering treatments and cures for human diseases and ailments. The Francis Crick Institute, when completed, will be one of the largest biomedical research facilities in Europe. It is a unique partnership between Cancer Research UK, the Medical Research Council, the Wellcome Trust, University College London (UCL), Imperial College London and King’s College London. As the client’s consultant, Arup w as involved in the evaluation of various sites before settling on the institute’s final location in 2008. The fi rm was appointed – after a competitive tendering process – to carry out the MEP engineering design, project management, fi re, security and logistics consultancy services. The 82,000m2 facility – which will house 1,500 scientists and support staff – consists of four basement levels, including two interstitial plant floors, and eight levels above ground, which will contain laboratory, plant, support, administration and amenity areas. The building is made up of two bars – north and south – which are connected by an eastwest atrium. The bars are further divided by a north-south atrium extending across the building. The location was carefully evaluated, placing the institute within a cluster of hospitals, educational institutions and learned societies, which are already working on some of today’s most important medical research. The project was conceived as a multidisciplinary, life-science research facility, incorporating primary and secondary shared/dedicated laboratory areas, plus associated write-up areas, biological research facilities (BRF) – with high-containment laboratories alongside chemistry and dry-lab functions – together with all the required amenity, administration, auditorium, restaurant and support functions. Each of these elements presents its own particular engineering and design requirements. The site is landlocked, with the British Library to the south, St Pancras Station to the east, and listed housing blocks to the north and west. Below ground, the surrounding streets are crowded with utilities, including two 120-year-old, low-pressure gas mains. The area is densely populated and there are two tube lines running underground, close to the site. The subterranean St Pancras Box –which incorporates the St Pancras International domestic rail station – is adjacent to the site, on the east side. Modern laboratory buildings can only accept extremely low levels of vibration transmitted within the building structure, so the project adopted a blanket level of Vibration Criteria-A (VC-A) across all laboratory floors, with local isolation tables in areas – such as the imaging zone – that required more stringent VC-D/E. All MEP plant and equipment that generates vibration must be fully isolated from the structure by means of anti-vibration mountings, spring hangers and supports. The sophisticated research equipment is very sensitive to electromagnetic emissions, which required the MEP equipment to be separated from any receivers by sufficient distances to eliminate interference. The most sensitive equipment has a further level of protection, with both passive and active shielding provided. Some research has to be conducted in laboratories with high containment levels – CL3 and CL3+ (the highest level). These are subject to stringent security checks by the Health and Safety Executive and must pass rigorous design reviews, called Hazop analyses, as well as qualitative risk assessment (QRA) for the CL3+ lab. This leads to an array of system component redundancy, and segregated/dedicated plant. The BRF, while not high-containment, is also subject to considerable scrutiny by the Home Office and the Department for Environment, Food and Rural Affairs (Defra). Very high levels of ventilation are required with 20 air changes per hour. The project also has sophisticated diurnal lighting control, acoustic control and high-efficiency particulate arrestance (HEPA) filtration of the air supplies and exhaust. The BRF also incorporates stringent odour control, which is dealt with primarily by careful architectural design, coupled with ventilation regimes. Emissions from air stacks carrying exhaust from laboratory fume cupboards, the BRF and the high-containment laboratories – as well as the flue discharges from gas-/oil-fired boilers and combined heat and power (CHP) generators – have been numerically modelled by the project environmental consultant. Discharges must satisfy both the Clean Air Act and the local authority with regard to contamination levels at local street-level receptor points. To ensure no discharges are returned into the building, a physical model was tested in a wind tunnel. To assess the nature and implications of the many engineering challenges facing the project, a number of studies were undertaken by the engineers and other specialists. See the ‘Engineering research’ box for the full list. The Francis Crick Institute is the first laboratory – and one of the first buildings of any type – to be subject to the latest (2010) energy regulations, which demand an average of approximately 25% reduction in carbon levels. This was achieved, along with an ‘Excellent’ BREEAM rating. The sustainable design measures were dictated by the London Plan, as well as Building Regulations. They include shading systems, a 2MVA CHP unit, and 1,700m2 of photovoltaics (see ‘Sustainable by design’ box).

== Configuration and architecture ==

MEP plant and systems have to be functional and adaptable, and fit within the overall architectural form of a building. The brief for the Francis Crick Institute was for it to be aesthetically pleasing, while providing good spatial planning and an efficient working environment. This presented considerable challenges to the architects, because space was constrained and there were stringent planning requirements. The impact of the building’s height and massing had to be carefully considered, particularly in relation to nearby housing, which had rights to light. To a large extent, this drives the MEP servicing strategies. The BRF is all in the 16m deep basement, along with most of the high-containment laboratories. This has meant large interstitial floors are required to accommodate the sizable HVAC and other services required to support these areas. To restrict and control the potential vibration of the structural-loading impacts of heavy plant, most of this is also located in the basement in its own energy centre. Air handling equipment requires large fresh air intake, as well as large discharge stacks. (The total fresh air requirement is 430m3/sec – equivalent of emptying an Olympic pool in less than 10 seconds.) For these reasons, the air handling units (AHUs) are on the upper plant floors. Electrical substations are located at both basement and roof levels, to be close to the main electrical loads. To distribute services from the plant areas to the occupied floors, large vertical distribution risers were created, running the height of the building. In addition, horizontal primary routes for services connecting between risers at each floor level – as well as providing service feeds to the floor itself – have been created in 1.5m-deep ceiling void spaces.

== Laboratory floors ==

The general laboratory areas consist of primary, shared secondary, dedicated secondary and write-up areas, based on a 6.2m x 9m structural grid, with adaptability built into the MEP design, to allow future changes driven by the science. Primary laboratories are main laboratories, which can accommodate a range of different sciences. Shared secondary laboratories contain high value assets, which are used extensively. Dedicated secondary laboratories are areas containing specific laboratory equipment that is dedicated to a particular area. The laboratory spaces on the north and south bars are designed to be open, with sight lines between laboratories. They are connected with link bridges and collaboration spaces to facilitate interaction between scientific groups. The general laboratory areas are designed – from the services point of view – to operate as a Containment Level 2 (CL2) area, with the write-up areas located outside the laboratory. The general laboratory system is a variable air volume (VAV) system, with supply and extract VAV units located within the structural grid. Within secondary laboratory areas, additional fan-coil units supplement the VAV cooling.

== Modular construction ==

The main contractor, Laing O’Rourke, adopted a pre-assembled modular approach to MEP services because of the size and scale of the project, and because of the constrained site and challenging construction programme. In addition to the 4,000-plus preassembled MEP modules, a further 2,000- plus prefabricated sections of pipework, containment and valve assemblies have been used in the construction of the MEP systems. This is in addition to the hundreds of thousands of other MEP products, and devices that have needed to be procured, delivered and installed on a ‘just in time’ basis. A separate article on modularisation and offsite assembly is planned for a future issue. Francis Crick was noted for his intelligence, openness to new ideas, and collaborations with different disciplines, and all of these qualities were needed by the engineering design team to deliver this groundbreaking project. 

== Engineering research ==

A great deal of modelling and analysis was carried out on the Francis Crick Institute before construction began:
*Acoustics and vibration – background acoustics levels and vibration signatures were measured, and then used as the baseline for compliance and mitigation measures
*Electromagnetic compatibility/interference – the profile of the site was assessed in order to establish background levels Environmental studies – a number of studies were performed, including the impact the building would have on existing air quality
*Daylighting – studies were performed to identify the impact the building would have on its surroundings, as well as the extent of natural daylight entering the buildings Thermal performance – the building was modelled with IES software to confirm compliance with Building Regulations, supporting the BREEAM assessment
*Dispersion modelling – numerical analysis to confirm that the 32 large extract air stacks and thermal flues are compliant with emissions requirements. In addition, wind-tunnel testing done to confirm emissions would not re-enter the fresh air intakes
*Odour modelling – conducted using both numerical and empirical testing of BRF waste and feed materials on exhaust streams. 
*Objective and subjective measures were used to access potential mitigation 
*Flooding impacts – assessed based on risk analysis and flood maps 
*Computation fluid dynamics – the heat flux in the data centre was assessed under both normal and equipment-failure scenarios 
*Lift traffic analysis – Elevate software was used to assess the number, size and location of the lifts.

== Project Team ==
*Client – Francis Crick (UKCMRI)
*Project manager – Arup Project Management
*Architects – HoK/PLP and BMJ
*MEP engineer – Arup
*Cost consultant – Turner and Townsend
*Structural engineer – AKT
*Main contractor – Laing O’Rourke

== Key data ==
*15 MVA electrical supply capacity
*7.5 MVA standby generation capacity
*2 MVA CHP plant
*300,000 litres diesel fuel storage
*4 x 4,000 kW water-cooled chillers
*3 x 6,500 kW steam boilers
*3 x 3,100 kW LTHW
*1 MW data centre
*13 passenger lifts
*9 goods lifts
*4 x 3,250 kg liquid carbon dioxide/liquid nitrogen tanks

== Sustainable by design ==

The project needed to satisfy the London Plan, as well as Part L of the Building Regulations. The London Plan describes an energy hierarchy: Be lean – energy efficiency beyond the current Building Regulations Be clean – priority given to connection to district heating networks and cogeneration Be green – on-site renewable energy generation. The following were incorporated into the design to improve energy-efficiency measures: high-performance glazing with shading systems; high-efficiency plant; lighting control and ventilation systems with variable volume flow. A 2 MVA CHP unit and connections to allow a future integration into a district heating scheme were also incorporated into the design. In addition, 1,700 m2 of solar photovoltaic panels were incorporated into the southern roof façade to generate energy that feeds into the electrical distribution.

To read the full article in the CIBSE Journal please [[Www.cibsejournal.com|click here]].

CIBSE Case Study Francis Crick Institute

2014-09-10T10:22:36Z

CIBSE:

''Article from the September 2014 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Steve Berry.''

One of the world’s largest biomedical research centres is nearing completion in a heavily built-up district of central London. 1953, Francis Crick – together with his colleagues James Watson and Maurice Wilkins – identified the structure of DNA . This proved to be of significant importance to biomedical research, and earned Crick, Watson and Wilkins the 1962 Nobel Prize in Physiology or Medicine. In 2015, the institute that bears his name will open its doors to the scientific community. Located opposite London’s St Pancras Station it will be an entirely new organisation, with a distinctive vision of how medical research should be conducted. This involves bringing the best minds together and engaging in extensive collaboration between scientists, biologists, chemists and physicists, with the aim of discovering treatments and cures for human diseases and ailments. The Francis Crick Institute, when completed, will be one of the largest biomedical research facilities in Europe. It is a unique partnership between Cancer Research UK, the Medical Research Council, the Wellcome Trust, University College London (UCL), Imperial College London and King’s College London. As the client’s consultant, Arup w as involved in the evaluation of various sites before settling on the institute’s final location in 2008. The fi rm was appointed – after a competitive tendering process – to carry out the MEP engineering design, project management, fi re, security and logistics consultancy services. The 82,000m2 facility – which will house 1,500 scientists and support staff – consists of four basement levels, including two interstitial plant floors, and eight levels above ground, which will contain laboratory, plant, support, administration and amenity areas. The building is made up of two bars – north and south – which are connected by an eastwest atrium. The bars are further divided by a north-south atrium extending across the building. The location was carefully evaluated, placing the institute within a cluster of hospitals, educational institutions and learned societies, which are already working on some of today’s most important medical research. The project was conceived as a multidisciplinary, life-science research facility, incorporating primary and secondary shared/dedicated laboratory areas, plus associated write-up areas, biological research facilities (BRF) – with high-containment laboratories alongside chemistry and dry-lab functions – together with all the required amenity, administration, auditorium, restaurant and support functions. Each of these elements presents its own particular engineering and design requirements. The site is landlocked, with the British Library to the south, St Pancras Station to the east, and listed housing blocks to the north and west. Below ground, the surrounding streets are crowded with utilities, including two 120-year-old, low-pressure gas mains. The area is densely populated and there are two tube lines running underground, close to the site. The subterranean St Pancras Box –which incorporates the St Pancras International domestic rail station – is adjacent to the site, on the east side. Modern laboratory buildings can only accept extremely low levels of vibration transmitted within the building structure, so the project adopted a blanket level of Vibration Criteria-A (VC-A) across all laboratory floors, with local isolation tables in areas – such as the imaging zone – that required more stringent VC-D/E. All MEP plant and equipment that generates vibration must be fully isolated from the structure by means of anti-vibration mountings, spring hangers and supports. The sophisticated research equipment is very sensitive to electromagnetic emissions, which required the MEP equipment to be separated from any receivers by sufficient distances to eliminate interference. The most sensitive equipment has a further level of protection, with both passive and active shielding provided. Some research has to be conducted in laboratories with high containment levels – CL3 and CL3+ (the highest level). These are subject to stringent security checks by the Health and Safety Executive and must pass rigorous design reviews, called Hazop analyses, as well as qualitative risk assessment (QRA) for the CL3+ lab. This leads to an array of system component redundancy, and segregated/dedicated plant. The BRF, while not high-containment, is also subject to considerable scrutiny by the Home Office and the Department for Environment, Food and Rural Affairs (Defra). Very high levels of ventilation are required with 20 air changes per hour. The project also has sophisticated diurnal lighting control, acoustic control and high-efficiency particulate arrestance (HEPA) filtration of the air supplies and exhaust. The BRF also incorporates stringent odour control, which is dealt with primarily by careful architectural design, coupled with ventilation regimes. Emissions from air stacks carrying exhaust from laboratory fume cupboards, the BRF and the high-containment laboratories – as well as the flue discharges from gas-/oil-fired boilers and combined heat and power (CHP) generators – have been numerically modelled by the project environmental consultant. Discharges must satisfy both the Clean Air Act and the local authority with regard to contamination levels at local street-level receptor points. To ensure no discharges are returned into the building, a physical model was tested in a wind tunnel. To assess the nature and implications of the many engineering challenges facing the project, a number of studies were undertaken by the engineers and other specialists. See the ‘Engineering research’ box for the full list. The Francis Crick Institute is the first laboratory – and one of the first buildings of any type – to be subject to the latest (2010) energy regulations, which demand an average of approximately 25% reduction in carbon levels. This was achieved, along with an ‘Excellent’ BREEAM rating. The sustainable design measures were dictated by the London Plan, as well as Building Regulations. They include shading systems, a 2MVA CHP unit, and 1,700m2 of photovoltaics (see ‘Sustainable by design’ box).

== Configuration and architecture ==

MEP plant and systems have to be functional and adaptable, and fit within the overall architectural form of a building. The brief for the Francis Crick Institute was for it to be aesthetically pleasing, while providing good spatial planning and an efficient working environment. This presented considerable challenges to the architects, because space was constrained and there were stringent planning requirements. The impact of the building’s height and massing had to be carefully considered, particularly in relation to nearby housing, which had rights to light. To a large extent, this drives the MEP servicing strategies. The BRF is all in the 16m deep basement, along with most of the high-containment laboratories. This has meant large interstitial floors are required to accommodate the sizable HVAC and other services required to support these areas. To restrict and control the potential vibration of the structural-loading impacts of heavy plant, most of this is also located in the basement in its own energy centre. Air handling equipment requires large fresh air intake, as well as large discharge stacks. (The total fresh air requirement is 430m3/sec – equivalent of emptying an Olympic pool in less than 10 seconds.) For these reasons, the air handling units (AHUs) are on the upper plant floors. Electrical substations are located at both basement and roof levels, to be close to the main electrical loads. To distribute services from the plant areas to the occupied floors, large vertical distribution risers were created, running the height of the building. In addition, horizontal primary routes for services connecting between risers at each floor level – as well as providing service feeds to the floor itself – have been created in 1.5m-deep ceiling void spaces.

== Laboratory floors ==

The general laboratory areas consist of primary, shared secondary, dedicated secondary and write-up areas, based on a 6.2m x 9m structural grid, with adaptability built into the MEP design, to allow future changes driven by the science. Primary laboratories are main laboratories, which can accommodate a range of different sciences. Shared secondary laboratories contain high value assets, which are used extensively. Dedicated secondary laboratories are areas containing specific laboratory equipment that is dedicated to a particular area. The laboratory spaces on the north and south bars are designed to be open, with sight lines between laboratories. They are connected with link bridges and collaboration spaces to facilitate interaction between scientific groups. The general laboratory areas are designed – from the services point of view – to operate as a Containment Level 2 (CL2) area, with the write-up areas located outside the laboratory. The general laboratory system is a variable air volume (VAV) system, with supply and extract VAV units located within the structural grid. Within secondary laboratory areas, additional fan-coil units supplement the VAV cooling.

== Modular construction ==

The main contractor, Laing O’Rourke, adopted a pre-assembled modular approach to MEP services because of the size and scale of the project, and because of the constrained site and challenging construction programme. In addition to the 4,000-plus preassembled MEP modules, a further 2,000- plus prefabricated sections of pipework, containment and valve assemblies have been used in the construction of the MEP systems. This is in addition to the hundreds of thousands of other MEP products, and devices that have needed to be procured, delivered and installed on a ‘just in time’ basis. A separate article on modularisation and offsite assembly is planned for a future issue. Francis Crick was noted for his intelligence, openness to new ideas, and collaborations with different disciplines, and all of these qualities were needed by the engineering design team to deliver this groundbreaking project. 

== Engineering research ==

A great deal of modelling and analysis was carried out on the Francis Crick Institute before construction began:
*Acoustics and vibration – background acoustics levels and vibration signatures were measured, and then used as the baseline for compliance and mitigation measures
*

Electromagnetic compatibility/interference – the profile of the site was assessed in order to establish background levels Environmental studies – a number of studies were performed, including the impact the building would have on existing air quality
*

Daylighting – studies were performed to identify the impact the building would have on its surroundings, as well as the extent of natural daylight entering the buildings Thermal performance – the building was modelled with IES software to confirm compliance with Building Regulations, supporting the BREEAM assessment
*

Dispersion modelling – numerical analysis to confirm that the 32 large

extract air stacks and thermal flues are compliant with emissions

requirements. In addition, wind-tunnel testing done to confirm emissions

would not re-enter the fresh air intakes 
*Odour modelling – conducted using both numerical and empirical testing of BRF waste and feed materials on exhaust streams. 
*Objective and subjective measures were used to access potential mitigation 
*Flooding impacts – assessed based on risk analysis and flood maps 
*Computation fluid dynamics – the heat flux in the data centre was assessed under both normal and equipment-failure scenarios 
*Lift traffic analysis – Elevate software was used to assess the number, size and location of the lifts.

== Project Team ==
*Client – Francis Crick (UKCMRI)
*Project manager – Arup Project Management
*Architects – HoK/PLP and BMJ
*MEP engineer – Arup
*Cost consultant – Turner and Townsend
*Structural engineer – AKT
*Main contractor – Laing O’Rourke

== Key data ==
*15 MVA electrical supply capacity
*7.5 MVA standby generation capacity
*2 MVA CHP plant
*300,000 litres diesel fuel storage
*4 x 4,000 kW water-cooled chillers
*3 x 6,500 kW steam boilers
*3 x 3,100 kW LTHW
*1 MW data centre
*13 passenger lifts
*9 goods lifts
*4 x 3,250 kg liquid carbon dioxide/liquid nitrogen tanks

== Sustainable by design ==

The project needed to satisfy the London Plan, as well as Part L of the Building Regulations. The London Plan describes an energy hierarchy: Be lean – energy efficiency beyond the current Building Regulations Be clean – priority given to connection to district heating networks and cogeneration Be green – on-site renewable energy generation. The following were incorporated into the design to improve energy-efficiency measures: high-performance glazing with shading systems; high-efficiency plant; lighting control and ventilation systems with variable volume flow. A 2 MVA CHP unit and connections to allow a future integration into a district heating scheme were also incorporated into the design. In addition, 1,700 m2 of solar photovoltaic panels were incorporated into the southern roof façade to generate energy that feeds into the electrical distribution.

To read the full article in the CIBSE Journal please [[Www.cibsejournal.com|click here]].

CIBSE Case Study Francis Crick Institute

2014-09-10T10:21:15Z

CIBSE: Created page with " ''Article from the September 2014 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Steve Berry.'' One of the world’s largest biomedical research ..."

''Article from the September 2014 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Steve Berry.'' 

One of the world’s largest biomedical research centres is nearing completion in a heavily built-up district of central London. 1953, Francis Crick – together with his colleagues James Watson and Maurice Wilkins – identified the structure of DNA . This proved to be of significant importance to biomedical research, and earned Crick, Watson and Wilkins the 1962 Nobel Prize in Physiology or Medicine. In 2015, the institute that bears his name will open its doors to the scientific community. Located opposite London’s St Pancras Station it will be an entirely new organisation, with a distinctive vision of how medical research should be conducted. This involves bringing the best minds together and engaging in extensive collaboration between scientists, biologists, chemists and physicists, with the aim of discovering treatments and cures for human diseases and ailments. The Francis Crick Institute, when completed, will be one of the largest biomedical research facilities in Europe. It is a unique partnership between Cancer Research UK, the Medical Research Council, the Wellcome Trust, University College London (UCL), Imperial College London and King’s College London. As the client’s consultant, Arup w as involved in the evaluation of various sites before settling on the institute’s final location in 2008. The fi rm was appointed – after a competitive tendering process – to carry out the MEP engineering design, project management, fi re, security and logistics consultancy services. The 82,000m2 facility – which will house 1,500 scientists and support staff – consists of four basement levels, including two interstitial plant floors, and eight levels above ground, which will contain laboratory, plant, support, administration and amenity areas. The building is made up of two bars – north and south – which are connected by an eastwest atrium. The bars are further divided by a north-south atrium extending across the building. The location was carefully evaluated, placing the institute within a cluster of hospitals, educational institutions and learned societies, which are already working on some of today’s most important medical research. The project was conceived as a multidisciplinary, life-science research facility, incorporating primary and secondary shared/dedicated laboratory areas, plus associated write-up areas, biological research facilities (BRF) – with high-containment laboratories alongside chemistry and dry-lab functions – together with all the required amenity, administration, auditorium, restaurant and support functions. Each of these elements presents its own particular engineering and design requirements. The site is landlocked, with the British Library to the south, St Pancras Station to the east, and listed housing blocks to the north and west. Below ground, the surrounding streets are crowded with utilities, including two 120-year-old, low-pressure gas mains. The area is densely populated and there are two tube lines running underground, close to the site. The subterranean St Pancras Box –which incorporates the St Pancras International domestic rail station – is adjacent to the site, on the east side. Modern laboratory buildings can only accept extremely low levels of vibration transmitted within the building structure, so the project adopted a blanket level of Vibration Criteria-A (VC-A) across all laboratory floors, with local isolation tables in areas – such as the imaging zone – that required more stringent VC-D/E. All MEP plant and equipment that generates vibration must be fully isolated from the structure by means of anti-vibration mountings, spring hangers and supports. The sophisticated research equipment is very sensitive to electromagnetic emissions, which required the MEP equipment to be separated from any receivers by sufficient distances to eliminate interference. The most sensitive equipment has a further level of protection, with both passive and active shielding provided. Some research has to be conducted in laboratories with high containment levels – CL3 and CL3+ (the highest level). These are subject to stringent security checks by the Health and Safety Executive and must pass rigorous design reviews, called Hazop analyses, as well as qualitative risk assessment (QRA) for the CL3+ lab. This leads to an array of system component redundancy, and segregated/dedicated plant. The BRF, while not high-containment, is also subject to considerable scrutiny by the Home Office and the Department for Environment, Food and Rural Affairs (Defra). Very high levels of ventilation are required with 20 air changes per hour. The project also has sophisticated diurnal lighting control, acoustic control and high-efficiency particulate arrestance (HEPA) filtration of the air supplies and exhaust. The BRF also incorporates stringent odour control, which is dealt with primarily by careful architectural design, coupled with ventilation regimes. Emissions from air stacks carrying exhaust from laboratory fume cupboards, the BRF and the high-containment laboratories – as well as the flue discharges from gas-/oil-fired boilers and combined heat and power (CHP) generators – have been numerically modelled by the project environmental consultant. Discharges must satisfy both the Clean Air Act and the local authority with regard to contamination levels at local street-level receptor points. To ensure no discharges are returned into the building, a physical model was tested in a wind tunnel. To assess the nature and implications of the many engineering challenges facing the project, a number of studies were undertaken by the engineers and other specialists. See the ‘Engineering research’ box for the full list. The Francis Crick Institute is the first laboratory – and one of the first buildings of any type – to be subject to the latest (2010) energy regulations, which demand an average of approximately 25% reduction in carbon levels. This was achieved, along with an ‘Excellent’ BREEAM rating. The sustainable design measures were dictated by the London Plan, as well as Building Regulations. They include shading systems, a 2MVA CHP unit, and 1,700m2 of photovoltaics (see ‘Sustainable by design’ box).

== Configuration and architecture ==

MEP plant and systems have to be functional and adaptable, and fit within the overall architectural form of a building. The brief for the Francis Crick Institute was for it to be aesthetically pleasing, while providing good spatial planning and an efficient working environment. This presented considerable challenges to the architects, because space was constrained and there were stringent planning requirements. The impact of the building’s height and massing had to be carefully considered, particularly in relation to nearby housing, which had rights to light. To a large extent, this drives the MEP servicing strategies. The BRF is all in the 16m deep basement, along with most of the high-containment laboratories. This has meant large interstitial floors are required to accommodate the sizable HVAC and other services required to support these areas. To restrict and control the potential vibration of the structural-loading impacts of heavy plant, most of this is also located in the basement in its own energy centre. Air handling equipment requires large fresh air intake, as well as large discharge stacks. (The total fresh air requirement is 430m3/sec – equivalent of emptying an Olympic pool in less than 10 seconds.) For these reasons, the air handling units (AHUs) are on the upper plant floors. Electrical substations are located at both basement and roof levels, to be close to the main electrical loads. To distribute services from the plant areas to the occupied floors, large vertical distribution risers were created, running the height of the building. In addition, horizontal primary routes for services connecting between risers at each floor level – as well as providing service feeds to the floor itself – have been created in 1.5m-deep ceiling void spaces.

== Laboratory floors ==

The general laboratory areas consist of primary, shared secondary, dedicated secondary and write-up areas, based on a 6.2m x 9m structural grid, with adaptability built into the MEP design, to allow future changes driven by the science. Primary laboratories are main laboratories, which can accommodate a range of different sciences. Shared secondary laboratories contain high value assets, which are used extensively. Dedicated secondary laboratories are areas containing specific laboratory equipment that is dedicated to a particular area. The laboratory spaces on the north and south bars are designed to be open, with sight lines between laboratories. They are connected with link bridges and collaboration spaces to facilitate interaction between scientific groups. The general laboratory areas are designed – from the services point of view – to operate as a Containment Level 2 (CL2) area, with the write-up areas located outside the laboratory. The general laboratory system is a variable air volume (VAV) system, with supply and extract VAV units located within the structural grid. Within secondary laboratory areas, additional fan-coil units supplement the VAV cooling.

== Modular construction ==

The main contractor, Laing O’Rourke, adopted a pre-assembled modular approach to MEP services because of the size and scale of the project, and because of the constrained site and challenging construction programme. In addition to the 4,000-plus preassembled MEP modules, a further 2,000- plus prefabricated sections of pipework, containment and valve assemblies have been used in the construction of the MEP systems. This is in addition to the hundreds of thousands of other MEP products, and devices that have needed to be procured, delivered and installed on a ‘just in time’ basis. A separate article on modularisation and offsite assembly is planned for a future issue. Francis Crick was noted for his intelligence, openness to new ideas, and collaborations with different disciplines, and all of these qualities were needed by the engineering design team to deliver this groundbreaking project. 

== Engineering research ==

A great deal of modelling and analysis was carried out on the Francis Crick Institute before construction began:
*Acoustics and vibration – background acoustics levels and vibration signatures were measured, and then used as the baseline for compliance and mitigation measures
*
Electromagnetic compatibility/interference – the profile of the site was assessed in order to establish background levels Environmental studies – a number of studies were performed, including the impact the
building would have on existing air quality
*
Daylighting – studies were performed to identify the impact the building would have on its surroundings, as well as the extent of natural daylight entering the buildings Thermal performance – the building was modelled with IES software to confirm compliance with Building Regulations, supporting the BREEAM assessment
*
Dispersion modelling – numerical analysis to confirm that the 32 large

extract air stacks and thermal flues are compliant with emissions
requirements. In addition, wind-tunnel testing done to confirm emissions
would not re-enter the fresh air intakes 
*Odour modelling – conducted using both numerical and empirical testing of BRF waste and feed materials on exhaust streams. 
*Objective and subjective measures were used to access potential mitigation 
*Flooding impacts – assessed based on risk analysis and flood maps 
*Computation fluid dynamics – the heat flux in the data centre was assessed under both normal and equipment-failure scenarios
*
Lift traffic analysis – Elevate software was used to assess the number, size and location of the lifts. 

== Project Team ==
*Client – Francis Crick (UKCMRI)
*Project manager – Arup Project Management
*Architects – HoK/PLP and BMJ
*MEP engineer – Arup
*Cost consultant – Turner and Townsend
*Structural engineer – AKT
*Main contractor – Laing O’Rourke

== Key data ==
*15 MVA electrical supply capacity
*7.5 MVA standby generation capacity
*2 MVA CHP plant
*300,000 litres diesel fuel storage
*4 x 4,000 kW water-cooled chillers
*3 x 6,500 kW steam boilers
*3 x 3,100 kW LTHW
*1 MW data centre
*13 passenger lifts
*9 goods lifts
*4 x 3,250 kg liquid carbon dioxide/liquid nitrogen tanks

== Sustainable by design ==

The project needed to satisfy the London Plan, as well as Part L of the Building Regulations. The London Plan describes an energy hierarchy: Be lean – energy efficiency beyond the current Building Regulations Be clean – priority given to connection to district heating networks and cogeneration Be green – on-site renewable energy generation. The following were incorporated into the design to improve energy-efficiency measures: high-performance glazing with shading systems; high-efficiency plant; lighting control and ventilation systems with variable volume flow. A 2 MVA CHP unit and connections to allow a future integration into a district heating scheme were also incorporated into the design. In addition, 1,700 m2 of solar photovoltaic panels were incorporated into the southern roof façade to generate energy that feeds into the electrical distribution.

To read the full article in the CIBSE Journal please [[www.cibsejournal.com|click here]].

CIBSE Case Study Angel Building Refurbishment

2014-07-31T15:04:22Z

CIBSE:

--[[User%3ACIBSE|CIBSE]] 14:41, 29 July 2014 (BST)

Article from the May 2012 edition of the [http://www.cibsejournal.com/ CIBSE Journal] written by Andy Pearson.

= Introduction =

Energy reduction was at the heart of the transformation of a drab central London office block into a CIBSE award-winning refurbishment. 

The key to the success of this project was to involve the design team to develop the building to reduce energy consumption in conjunction with the building services solution,’ says Danny Hall, associate director at consulting engineers Norman Disney & Young (NDY). Hall is talking about the £70m reinvention of the Angel Building – a transformation from an ugly, inefficient 1980s commercial property into a swanky, modern office that is also a showcase for sustainable refurbishment.

The scheme’s recent triumph at the CIBSE Building Performance Awards 2012 – where it was the Refurbishment Project of the Year – and its shortlisting for architecture’s 2011 Stirling Prize, are a testament to the success of this transformation.

Situated on a busy crossroads in Islington, north London, the revamped building has a sleek, curved slate-coloured façade. Inside the building, the street’s hubbub gives way to a cool, restrained interior centred on an impressive atrium that affords glimpses of five floors of modern offices.

Fundamental to the building’s reincarnation has been the retention of its concrete structure. NDY has been involved in the makeover from the outset, both as environmental engineers and sustainability consultants. It was the firm’s analysis – demonstrating how much carbon could be saved by retaining the structure – that convinced the design team this was an option worth pursuing. ‘It saved about 7,400 tonnes of CO2, so it made a lot of sense to keep the structure,’ says Hall.

To tease every inch of extra space out of the site, the architect discarded the original cladding and sympathetically extended the structure to maximise the floor areas. At the front of the building this extension takes the form of a curved, steel-framed addition that follows the bend of one of merging roads, St John Street. A smaller, rectilinear extension has also been added to the southern elevation, while a new fifth floor has been added to the along with two spacious roof terraces giving views over north London.

In addition to the perimeter extensions, the floor plates have also expanded into the large central courtyard. The remainder of this opening is now covered by a transparent polymer roof of ETFE pillows to form the central atrium. In all, the addition of a new floor and extensions to the existing office floors has added over 60% more lettable space for the developers, Derwent London.

The scheme now totals more than 24,000 sq m of high-specification office space, along with an atrium, retail outlets and new roof terraces. ‘We’ve been able to generate a significant amount of new space,’ Hall explains.

Energy reduction was at the heart of this transformation. The re-used structure saved a significant amount of embodied carbon; the challenge for the building services design was to build on this achievement and come up with an energy efficient, environmental solution to complement the structural solution.

The engineers were helped in their task by the existing structure, which was based on a significant floor-to-ceiling height of 3.5m. ‘We inherited a building with fairly generous floor slab to ceiling slab heights, which opened up a lot of options for the type of cooling and heating systems we could install,’ says Hall.

As part of the renovations, a new fifth floor has been added to the roof, along with two spacious roof terraces giving views over north London.

= Cooling =

The designers looked at a number of options to provide cooling to the office floors – including fan coil units, chilled beams and chilled ceilings – before settling on an air displacement system. ‘In the end we decided to exploit the exposed soffits by opting for a displacement ventilation system concealed within a new 450 mm raised floor,’ says Hall.

Displacement air is introduced to the offices through grilles set in the floor. This arrangement restricts the minimum temperature at which air can be introduced to 19C which, in turn, limits the amount of cooling the system can achieve. ‘Because we’re introducing air close to people it cannot be too cold or they will feel a draught,’ Hall explains.

The upside of supplying air at this temperature is that it allows the building to run in ‘free cooling’ mode for 80% of the time. ‘At 19C we don’t have to cool the outside air for most of the year, we don’t have to use the water-cooled chillers, so we save loads of energy,’ says Hall. Another big advantage of this approach is that using mostly outside air helps keep the office environment feeling fresh. The downside is that the fans still have to run to push all this air through of the offices.

Another potential drawback of the system is that NDY was concerned that the displacement air would heat up in contact with the floor slab. The problem arises because air temperatures can reach 27C close to the ceiling soffit, heating the floor slab of the offices above. NDY had data from tests carried out in Germany showing that, depending on the temperature difference and the distance air travels in contact with the slab, the supply air temperature could increase by up to 2.5C. A temperature increase of this magnitude would significantly reduce the amount of cooling available, particularly at the perimeter of the floor plates, where the system has to cope with solar gains in addition to occupancy gains.

Hall’s solution is to deliver the air from the service cores to the floor perimeters in insulated ducts concealed within the raised floors. Each of the building’s floors is divided into quarters to allow the building to be subdivided for letting. Each of those quarters is served by a riser. Hall’s solution allows the temperature and quantity of air reaching a specific floor area to be targeted precisely. It also allows air to be ducted to cellular offices, where these have been installed by tenants. Air is extracted from the offices at high level through grilles set into the cores, and then ducted back to the roof-mounted air handling units.

= Façade =

Design of the building’s façade was critical for the displacement system to perform effectively. ‘We knew the maximum cooling capacity of the system, which was about 75W/sq m tops, so once we’d taken off the cooling needed to deal with the loads of a modern office, we were left with the maximum cooling load we could handle at the façade,’ says Hall.

To keep the cooling load within this limit the engineers worked closely with the project architect, Allford Hall Monaghan and Morris (AHMM), to develop a façade solution that balanced high performance glazing with solid elements. In the end the designers opted for high performance neutral-coloured glazing with a G-value of about 0.3 and low level solid elements on each floor. However, even with this type of glazing, to keep the solar gain within manageable limits a 500 mm band of fritting had to be added to the top of the glazing to provide additional shading.

The windows are fitted with internal blinds for glare control. To prevent heat build-up close to the glazing, NDY and AHMM developed a neat return air detail. According to Hall, when the sun hits the blind, the blind heats up and the heat form changes from radiant to convective. Their solution has been to incorporate a return air slot detail in the box housing the blind to remove this convective element as it rises upwards.

Careful detailing has also been used to extract air from beneath the soffit in areas where the floor plates have been extended. An existing downstand beam marks the outer limit of the original floor plate; this protrudes into the offices from the soffit. The intrusion impacted the flow of warm air along the soffit back to the return air grille at the cores. Tests by NDY in Germany had shown that without intervention, returning warm air at high level would dislodge from the soffit at the obstruction and fall into the occupied zone.

In another neat solution, to overcome this particular challenge the engineers designed an extension to the extract system to draw air through a shadow-gap created between the plasterboard ceiling panels of the new floor plate extensions and the downstand beam. The extract air is carried from high level to the floor void through ducts concealed within the webs of the steel columns that support the new structure. Once in the floor void, the warmed air is routed back to the main return air ducts in the cores.

The scheme also includes openable windows controlled by the occupants at will. About half of the windows can be opened. Hall says that because the displacement ventilation system is designed to use outside air for much of the year, the system is able to cope with additional air ‘better than most other systems’. The windows do not form part of the night time ventilation strategy; instead the air handling units run at night, with the cooling system off, to purge the structure of the day’s residual heat. The design of the building's façade was crucial to the performance of an internal air displacement system.

The lighting scheme, too, was influenced by the cooling system. NDY restricted the heat output from the lighting to a maximum of 12W/sq m. ‘It was quite a challenge to maintain the design at that level but if we’d gone over, the lighting would have impacted on the cooling available for the space,’ explains Hall. The solution developed uses suspended high efficiency fluorescent fittings with daylight and PIR controls as part of a DALI system.

The lighting solution has been enhanced around the atrium, where the new infill has created deeper floor plates. The number of fittings has been increased in this area to give the impression of higher levels of light entering from the atrium than is actually the case. ‘The light in this area has been enhanced to make the offices feel light and open,’ says Hall. Lighting was carefully designed to avoid impacting on the cooling load limit

= Heating =

In winter the return air from the offices, which can be at temperatures as high as 27C, is mixed with the outside air to achieve the 19C supply air temperature without having to use additional heat. The solution can recover up to 65% of the heat that would otherwise be thrown away. ‘It’s a really efficient system,’ says Hall.

When heating is needed, it is provided by a combination of three gas and two biomass boilers. The biomass was installed because, at the time the scheme achieved planning approval, the rules required a 10% reduction in the building’s carbon emissions from renewable technologies.

‘We tried to minimise energy use by making the building as lean as possible through the improved façade performance, our system selection and the plant efficiencies,’ says Hall. As a result, the biomass boilers are the scheme’s only renewables.

The two biomass boilers, located in the main ground floor plant room, provide 15% of the overall heat demand. In summer, a 550 kW boiler is sufficient to meet the hot water demand. Hot water is delivered to each toilet block via a hydraulic interface unit complete with a heat exchanger. In winter, a larger 900 kW boiler will supply additional heat for the ventilation system heater batteries, office perimeter trench heating and the below-floor fan coil unit for the main entrance door. The gas boilers provide supplementary heating when necessary. Variable speed pumps on both the heating and chilled water systems help match the circuit flow rate to demand.

Unlike gas boilers, which can be turned on and off instantly, biomass boilers are less responsive. ‘If the biomass boilers are servicing a big demand and that demand suddenly drops you cannot turn them off instantly,’ says Hall. To allow the boilers to consume any remaining fuel, Hall has included a giant 20,000 litre hot water storage vessel in the heating/hot water primary circuit to act as a thermal buffer, ensuring biomass boilers can run efficiently.

The hot water store also helps prevent corrosion in the boilers by keeping the water circuit warm. ‘Biomass boilers don’t like being fed cold water, so the hot water store helps provide back-end protection by maintaining a minimum return temperature,’ explains Hall.

Proof of the effectiveness of the building services solution is in the scheme being awarded a BREEAM Excellent rating. It has also achieved a B rating Energy Performance Certificate. ‘It’s an impressive performance from a 1980s building,’ says Hall. ‘But then it was a pretty heavy refurbishment,’ he adds.

= Carbon footprint: recycling the structure =

Re-use of the existing structure helps limit the carbon footprint of the development and significantly reduces the transport and disposal of demolition and construction waste, which reduces emissions and minimises dust creation.

The omission of unnecessary finishes and fixtures such as suspended ceilings helps expose the thermal mass and also reduces the amount of energy embodied in the finishes and their maintenance.

Using the concrete carbon calculator and data from the University of Bath, NDY estimated that the retained structure accounts for 39,500 tonnes of concrete, or about 30,000cu m, which is equivalent to about 7,400 tonnes of CO2 or running the operational elements of the building for 13 years.

{| class="responsive"
|-
| '''Basic building loads'''
| '''kWhr/sq m/yr'''
| '''kg/CO/sq m/yr'''
|-
| Heating (gas and biomass)
| 6.43
| 0.25
|-
| Hot water (gas and biomass)
| 5.32
| 0.15
|-
| Electricity - lighting
| 26.40
| 11.14
|-
| Electrical building services
| 8.92
| 3.76
|-
| Electrical cooling
| 4.44
| 1.87
|-
| '''Subtotal'''
| 51.5
| 17.7
|-
| colspan="3" |
''Projected, estimated energy loads of the services, based on '' ''Energy Performance Certificate data (Source: Norman Disney & Young)''

|}

= Project team =

Client: Derwent London Environmental and fire engineer: Norman Disney & Young Architect: Allford Hall Monaghan Morris Structural engineers: Adams Kara Taylor Main contractor: BAM Project managers: Buro Four Cost consultants: Davis Langdon Lighting consultants: Equation

----

For the full article on the CIBSE website [http://www.cibse.org/knowledge/case-studies/cibse-case-study-angel-building-refurbishment click here.]

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