- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 30 Aug 2017
Passive design maximises the use of ‘natural’ sources of heating, cooling and ventilation to create comfortable conditions inside buildings. It harness environmental conditions such as solar radiation, cool night air and air pressure differences to drive the internal environment. Passive measures do not involve mechanical or electrical systems.
This is as opposed to ‘active’ design which makes use of active building services systems to create comfortable conditions, such as boilers and chillers, mechanical ventilation, electric lighting and so on. Buildings will generally include both active and passive measures.
Solar chimneys are generally tall, wide structures constructed, facing the sun, with a dark coloured, matt surface designed to absorb solar radiation. As the chimney becomes hot, so it heats the air inside it. The hot air rises up the chimney and is vented out of the top, and in so doing it draws more air in at the bottom of the chimney. This can be used to drive passive ventilation in buildings where cross ventilation or stack ventilation may not be sufficient, and where designers wish to avoid using energy-consuming mechanical ventilation.
Solar chimneys are particularly effective in climates that are humid and hot. They are most efficient when they are tall and wide, but not very deep. This maximises the surface area that can absorb solar radiation and maximises the surface area in contact with the air inside the chimney.
Variations in design can incorporate multiple chambers to further increase surface area and may use materials with high solar absorption such as metal to maximise the temperatures achieved within the chimney. Low emissivity coatings, and glazing can also be used to reduce heat losses back to the outside, similar to the design of trombe walls.
It is important that the chimney is insulated from the building itself so that heat gains do not transmit into occupied spaces. In cooler conditions, the chimney can be used to direct absorbed heat back into the building by closing it at the top.
 Related articles on Designing Buildings Wiki
Featured articles and news
Grouting refers to the injection of materials into a soil or rock formation to change its physical characteristics.
Part of Designing Buildings Wiki, BREEAM Wiki will advance knowledge sharing for the BRE family of sustainability tools.
From the decorative to the utilitarian, and from the photographed to the forgotten.
New BRE book considers the progression from project-based knowledge creation to whole-life urban knowledge management.
This CIOB article explores the concept of value in building design and construction.
BREEAM and Measurabl announce integration to improve the financial performance of commercial real estate.
Rogers Stirk Harbour + Partners' release new images of soon-to-open 3WTC tower in New York.
A document can be called a bond or a guarantee. Does the name matter and what is the difference between them?
New briefing note is launched focusing on increasing knowledge of housing that promotes health and wellbeing.
Arbitration is a private, contractual form of dispute resolution used in the construction industry.
The European Parliament has approved a revised Energy Performance of Buildings directive.
One in six MPs supports the ring-fencing of retentions as proposed in the 'Aldous Bill'.