Mechanical ventilation with heat recovery MVHR - Revision history

Designing Buildings at 07:32, 21 February 2025

2025-02-21T07:32:25Z

← Older revision		Revision as of 07:32, 21 February 2025
Line 15:		Line 15:
	To reduce the heat lost to the outside as a result of this mechanical ventilation, mechanical ventilation with heat recovery (MVHR) can be used.		To reduce the heat lost to the outside as a result of this mechanical ventilation, mechanical ventilation with heat recovery (MVHR) can be used.

−	Approved document F: Volume 1: Dwellings, 2021 edition, defines mechanical ventilation with heat recovery A mechanically driven ventilation system that both continuously supplies outdoor air to the inside of the dwelling and continuously extracts indoor air and discharges it to the outside. For the purposes of this approved document, the guidance for mechanical ventilation with heat recovery applies to centralised or decentralised supply and extract systems, with or without heat recovery.’	+	Approved document F: Volume 1: Dwellings, 2021 edition, defines mechanical ventilation with heat recovery as: 'A mechanically driven ventilation system that both continuously supplies outdoor air to the inside of the dwelling and continuously extracts indoor air and discharges it to the outside. For the purposes of this approved document, the guidance for mechanical ventilation with heat recovery applies to centralised or decentralised supply and extract systems, with or without heat recovery.’

	Whole-house, or multi-room MVHR involves installing ductwork to each room, typically in ceiling voids, and running these ducts to a heat recovery unit, often located in the loft space. Air is continually extracted from rooms that might be warm and humid, such as bathrooms and kitchens. This is passed through a heat exchanger in the heat recovery unit where ‘waste’ heat is recovered from the air before it is rejected to the outside. The heat exchanger uses the recovered heat to ‘temper’ incoming fresh air that is used to supply the non-humid ‘habitable’ rooms such as bedrooms and living rooms. Tempering the incoming air reduces the need for heating, and so reduces energy use.		Whole-house, or multi-room MVHR involves installing ductwork to each room, typically in ceiling voids, and running these ducts to a heat recovery unit, often located in the loft space. Air is continually extracted from rooms that might be warm and humid, such as bathrooms and kitchens. This is passed through a heat exchanger in the heat recovery unit where ‘waste’ heat is recovered from the air before it is rejected to the outside. The heat exchanger uses the recovered heat to ‘temper’ incoming fresh air that is used to supply the non-humid ‘habitable’ rooms such as bedrooms and living rooms. Tempering the incoming air reduces the need for heating, and so reduces energy use.

Designing Buildings at 07:29, 21 February 2025

2025-02-21T07:29:50Z

← Older revision		Revision as of 07:29, 21 February 2025
Line 15:		Line 15:
	To reduce the heat lost to the outside as a result of this mechanical ventilation, mechanical ventilation with heat recovery (MVHR) can be used.		To reduce the heat lost to the outside as a result of this mechanical ventilation, mechanical ventilation with heat recovery (MVHR) can be used.

−	Approved ~~Document~~ F, ~~of the building regulations ‘Means of ventilation’ describes~~ mechanical ventilation with heat recovery ~~as, ‘continuous mechanical supply and extract with heat recovery’. It is commonly used in housing to extract stale air and supply fresh~~ air ~~whilst recovering up~~ to ~~95%~~ of ~~heat that would otherwise have been lost from~~ the ~~extract~~ air and ~~using~~ it to ~~pre-heat~~ the supply ~~air~~.	+	Approved document F: Volume 1: Dwellings, 2021 edition, defines mechanical ventilation with heat recovery A mechanically driven ventilation system that both continuously supplies outdoor air to the inside of the dwelling and continuously extracts indoor air and discharges it to the outside. For the purposes of this approved document, the guidance for mechanical ventilation with heat recovery applies to centralised or decentralised supply and extract systems, with or without heat recovery.’

	Whole-house, or multi-room MVHR involves installing ductwork to each room, typically in ceiling voids, and running these ducts to a heat recovery unit, often located in the loft space. Air is continually extracted from rooms that might be warm and humid, such as bathrooms and kitchens. This is passed through a heat exchanger in the heat recovery unit where ‘waste’ heat is recovered from the air before it is rejected to the outside. The heat exchanger uses the recovered heat to ‘temper’ incoming fresh air that is used to supply the non-humid ‘habitable’ rooms such as bedrooms and living rooms. Tempering the incoming air reduces the need for heating, and so reduces energy use.		Whole-house, or multi-room MVHR involves installing ductwork to each room, typically in ceiling voids, and running these ducts to a heat recovery unit, often located in the loft space. Air is continually extracted from rooms that might be warm and humid, such as bathrooms and kitchens. This is passed through a heat exchanger in the heat recovery unit where ‘waste’ heat is recovered from the air before it is rejected to the outside. The heat exchanger uses the recovered heat to ‘temper’ incoming fresh air that is used to supply the non-humid ‘habitable’ rooms such as bedrooms and living rooms. Tempering the incoming air reduces the need for heating, and so reduces energy use.

Editor at 21:47, 29 January 2025

2025-01-29T21:47:04Z

← Older revision		Revision as of 21:47, 29 January 2025
Line 50:		Line 50:
	* Mechanical ventilation.		* Mechanical ventilation.
	* Natural ventilation.		* Natural ventilation.
		+	* Reasons for using MVHR systems.
	* Stack effect.		* Stack effect.
	* Thermal comfort.		* Thermal comfort.

Editor at 21:46, 29 January 2025

2025-01-29T21:46:34Z

← Older revision		Revision as of 21:46, 29 January 2025
Line 33:		Line 33:
	NB [https://www.gov.uk/government/publications/ventilation-approved-document-f Domestic Ventilation Compliance Guide, 2010 Edition (with 2011 amendments)], published by the Department for Communities and Local Government in July 2011, defines continuous mechanical balanced ventilation with heat recovery (MVHR) as: ‘… a ventilation system that comprises central ducted supply and extract fans, air being supplier into the habitable rooms via a heat recovery unit.’		NB [https://www.gov.uk/government/publications/ventilation-approved-document-f Domestic Ventilation Compliance Guide, 2010 Edition (with 2011 amendments)], published by the Department for Communities and Local Government in July 2011, defines continuous mechanical balanced ventilation with heat recovery (MVHR) as: ‘… a ventilation system that comprises central ducted supply and extract fans, air being supplier into the habitable rooms via a heat recovery unit.’

−	= Related articles on Designing Buildings ~~Wiki~~ =	+	= Related articles on Designing Buildings =

	* Air conditioning.		* Air conditioning.

Designing Buildings at 07:40, 5 November 2020

2020-11-05T07:40:48Z

← Older revision		Revision as of 07:40, 5 November 2020
Line 54:		Line 54:
	* Ventilation.		* Ventilation.

−	[[Category:~~Products_/_components~~]] [[Category:DCN_Product_Knowledge]]	+	[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:DCN_Product_Knowledge]] [[Category:Products_/_components]]

Designing Buildings at 10:10, 11 June 2020

2020-06-11T10:10:08Z

← Older revision		Revision as of 10:10, 11 June 2020
Line 1:		Line 1:
−	~~See also: Exhaust air heat pump.~~
−
	Ventilation is necessary in buildings to remove ‘stale’ air and replace it with ‘fresh’ air:		Ventilation is necessary in buildings to remove ‘stale’ air and replace it with ‘fresh’ air:

Line 31:		Line 29:
	=== Optimised ductwork design ===		=== Optimised ductwork design ===

−	MVHR ductwork should be arranged so the connection to the world is as short as possible. Insulate both ducts that connect the MVHR to the world. This is intended to prevent condensation on the outside of the incoming pipe and the inside of the outgoing pipe. Have all the duct runs between rooms and MVHR within the thermal envelope of the house. This means they need no insulating. The air that they're carrying is as warm as the house air, essentially so if they run through a cold space they will cool. This is either your warmed fresh air that is cooling, or it's your heat laden stale air. Loss of heat from either represents a loss of heat from the warm envelope~~.<br />~~	+	MVHR ductwork should be arranged so the connection to the world is as short as possible. Insulate both ducts that connect the MVHR to the world. This is intended to prevent condensation on the outside of the incoming pipe and the inside of the outgoing pipe. Have all the duct runs between rooms and MVHR within the thermal envelope of the house. This means they need no insulating. The air that they're carrying is as warm as the house air, essentially so if they run through a cold space they will cool. This is either your warmed fresh air that is cooling, or it's your heat laden stale air. Loss of heat from either represents a loss of heat from the warm envelope.
−	~~<br />~~	+
−	~~So between room and MVHR you care about losing the valuable heat. Between the MVHR and world you care about the nuisance condensation. Being insulated or in a warm envelope addresses both problems~~.	+

−	~~= Find out more =~~	+	NB [https://www.gov.uk/government/publications/ventilation-approved-document-f Domestic Ventilation Compliance Guide, 2010 Edition (with 2011 amendments)], published by the Department for Communities and Local Government in July 2011, defines continuous mechanical balanced ventilation with heat recovery (MVHR) as: ‘… a ventilation system that comprises central ducted supply and extract fans, air being supplier into the habitable rooms via a heat recovery unit.’

−	=== Related articles on Designing Buildings Wiki ===	+	= Related articles on Designing Buildings Wiki =

	* Air conditioning.		* Air conditioning.
Line 58:		Line 54:
	* Ventilation.		* Ventilation.

−	[[Category:Products_/_components]]	+	[[Category:Products_/_components]] [[Category:DCN_Product_Knowledge]]

Needleandmortar at 17:21, 12 January 2016

2016-01-12T17:21:12Z

← Older revision		Revision as of 17:21, 12 January 2016
Line 1:		Line 1:
−
	See also: Exhaust air heat pump.		See also: Exhaust air heat pump.

	Ventilation is necessary in buildings to remove ‘stale’ air and replace it with ‘fresh’ air:		Ventilation is necessary in buildings to remove ‘stale’ air and replace it with ‘fresh’ air:
−	*Helping to moderate internal temperatures.	+
−	*Replenishing oxygen.	+	* Helping to moderate internal temperatures.
−	*Reducing the accumulation of moisture, odours, bacteria, dust, carbon dioxide, smoke and other contaminants that can build up during occupied periods.	+	* Replenishing oxygen.
−	*Creating air movement which improves the comfort of occupants.	+	* Reducing the accumulation of moisture, odours, bacteria, dust, carbon dioxide, smoke and other contaminants that can build up during occupied periods.
		+	* Creating air movement which improves the comfort of occupants.

	Very broadly, ventilation in buildings can be classified as ‘natural’ or ‘mechanical’.		Very broadly, ventilation in buildings can be classified as ‘natural’ or ‘mechanical’.
−	*Mechanical (or ‘forced’) ventilation tends to be driven by fans.	+
−	*Natural ventilation is driven by ‘natural’ pressure differences from one part of the building to another.	+	* Mechanical (or ‘forced’) ventilation tends to be driven by fans.
		+	* Natural ventilation is driven by ‘natural’ pressure differences from one part of the building to another.

	Traditionally, many buildings were ventilated largely by natural ventilation or 'infiltration', with fresh air entering spaces when doors or windows were opened, or through gaps in the fabric of the building. However, as the building regulations have become increasingly strict, and build quality has improved, buildings have become more air-tight and ventilation is increasingly provided mechanically.		Traditionally, many buildings were ventilated largely by natural ventilation or 'infiltration', with fresh air entering spaces when doors or windows were opened, or through gaps in the fabric of the building. However, as the building regulations have become increasingly strict, and build quality has improved, buildings have become more air-tight and ventilation is increasingly provided mechanically.
Line 27:		Line 28:

	Regular maintenance is required to ensure that fans are operating correctly and filters remain clean.		Regular maintenance is required to ensure that fans are operating correctly and filters remain clean.
		+
		+	=== Optimised ductwork design ===
		+
		+	MVHR ductwork should be arranged so the connection to the world is as short as possible. Insulate both ducts that connect the MVHR to the world. This is intended to prevent condensation on the outside of the incoming pipe and the inside of the outgoing pipe. Have all the duct runs between rooms and MVHR within the thermal envelope of the house. This means they need no insulating. The air that they're carrying is as warm as the house air, essentially so if they run through a cold space they will cool. This is either your warmed fresh air that is cooling, or it's your heat laden stale air. Loss of heat from either represents a loss of heat from the warm envelope.<br />
		+	<br />
		+	So between room and MVHR you care about losing the valuable heat. Between the MVHR and world you care about the nuisance condensation. Being insulated or in a warm envelope addresses both problems.

	= Find out more =		= Find out more =

	=== Related articles on Designing Buildings Wiki ===		=== Related articles on Designing Buildings Wiki ===
−	*Air conditioning.	+
−	*Air infiltration testing.	+	* Air conditioning.
−	*Building services.	+	* Air infiltration testing.
−	*Condensation.	+	* Building services.
−	*Cross ventilation.	+	* Condensation.
−	*Displacement ventilation.	+	* Cross ventilation.
−	*Domestic ventilation systems performance.	+	* Displacement ventilation.
−	*Exhaust air heat pump.	+	* Domestic ventilation systems performance.
−	*Flanking sound.	+	* Exhaust air heat pump.
−	*Heat recovery.	+	* Flanking sound.
−	*Humidity.	+	* Heat recovery.
−	*HVAC.	+	* Humidity.
−	*Interstitial condensation.	+	* HVAC.
−	*Mechanical ventilation.	+	* Interstitial condensation.
−	*Natural ventilation.	+	* Mechanical ventilation.
−	*Stack effect.	+	* Natural ventilation.
−	*Thermal comfort.	+	* Stack effect.
−	*Ventilation.	+	* Thermal comfort.
		+	* Ventilation.

	[[Category:Products_/_components]]		[[Category:Products_/_components]]

Designing Buildings at 10:18, 17 November 2015

2015-11-17T10:18:55Z

← Older revision		Revision as of 10:18, 17 November 2015
Line 1:		Line 1:
		+
		+	See also: Exhaust air heat pump.

	Ventilation is necessary in buildings to remove ‘stale’ air and replace it with ‘fresh’ air:		Ventilation is necessary in buildings to remove ‘stale’ air and replace it with ‘fresh’ air:
Line 8:		Line 10:
	Very broadly, ventilation in buildings can be classified as ‘natural’ or ‘mechanical’.		Very broadly, ventilation in buildings can be classified as ‘natural’ or ‘mechanical’.
	*Mechanical (or ‘forced’) ventilation tends to be driven by fans.		*Mechanical (or ‘forced’) ventilation tends to be driven by fans.
−	*Natural ventilation is driven by ‘natural’ pressure differences from one part of the building to another.	+	*Natural ventilation is driven by ‘natural’ pressure differences from one part of the building to another.

−	Traditionally, many buildings were ventilated largely by natural ventilation or 'infiltration', with fresh air entering spaces when doors or windows were opened, or through gaps in the fabric of the building. However, as the building regulations have become increasingly strict, and build quality has improved, buildings have become more air-tight and ventilation is increasingly provided mechanically.	+	Traditionally, many buildings were ventilated largely by natural ventilation or 'infiltration', with fresh air entering spaces when doors or windows were opened, or through gaps in the fabric of the building. However, as the building regulations have become increasingly strict, and build quality has improved, buildings have become more air-tight and ventilation is increasingly provided mechanically.

	To reduce the heat lost to the outside as a result of this mechanical ventilation, mechanical ventilation with heat recovery (MVHR) can be used.		To reduce the heat lost to the outside as a result of this mechanical ventilation, mechanical ventilation with heat recovery (MVHR) can be used.
Line 36:		Line 38:
	*Displacement ventilation.		*Displacement ventilation.
	*Domestic ventilation systems performance.		*Domestic ventilation systems performance.
		+	*Exhaust air heat pump.
	*Flanking sound.		*Flanking sound.
	*Heat recovery.		*Heat recovery.

Designing Buildings at 12:16, 16 February 2015

2015-02-16T12:16:47Z

← Older revision		Revision as of 12:16, 16 February 2015
Line 8:		Line 8:
	Very broadly, ventilation in buildings can be classified as ‘natural’ or ‘mechanical’.		Very broadly, ventilation in buildings can be classified as ‘natural’ or ‘mechanical’.
	*Mechanical (or ‘forced’) ventilation tends to be driven by fans.		*Mechanical (or ‘forced’) ventilation tends to be driven by fans.
−	*Natural ventilation is driven by ‘natural’ pressure differences from one part of the building to another~~. Natural ventilation can be wind-driven or buoyancy-driven. For more information see Stack effect and Cross ventilation~~.	+	*Natural ventilation is driven by ‘natural’ pressure differences from one part of the building to another.

−	Traditionally, many buildings were ventilated largely by natural ventilation or infiltration, with fresh air entering spaces when doors or windows were opened, or through gaps in the fabric of the building. However, as the building regulations have become increasingly strict, and build quality has improved, ventilation is increasingly provided mechanically. To reduce the heat lost to the outside as a result of mechanical ventilation, mechanical ventilation with heat recovery (MVHR) can be used.	+	Traditionally, many buildings were ventilated largely by natural ventilation or 'infiltration', with fresh air entering spaces when doors or windows were opened, or through gaps in the fabric of the building. However, as the building regulations have become increasingly strict, and build quality has improved, buildings have become more air-tight and ventilation is increasingly provided mechanically.
		+
		+	To reduce the heat lost to the outside as a result of this mechanical ventilation, mechanical ventilation with heat recovery (MVHR) can be used.

	Approved Document F, of the building regulations ‘Means of ventilation’ describes mechanical ventilation with heat recovery as, ‘continuous mechanical supply and extract with heat recovery’. It is commonly used in housing to extract stale air and supply fresh air whilst recovering up to 95% of heat that would otherwise have been lost from the extract air and using it to pre-heat the supply air.		Approved Document F, of the building regulations ‘Means of ventilation’ describes mechanical ventilation with heat recovery as, ‘continuous mechanical supply and extract with heat recovery’. It is commonly used in housing to extract stale air and supply fresh air whilst recovering up to 95% of heat that would otherwise have been lost from the extract air and using it to pre-heat the supply air.

−	Whole-house, or multi-room MVHR involves installing ductwork to each room, typically in ceiling voids and running these ducts to a heat recovery unit, often located in the loft space. Air is continually extracted from rooms that might be warm and humid, such as bathrooms and kitchens. This is passed through a heat exchanger in the heat recovery unit where ‘waste’ heat is recovered from the air before it is rejected to the outside. The heat exchanger uses the recovered heat to ‘temper’ incoming fresh air that is used to supply the non-humid ‘habitable’ rooms such as bedrooms and living rooms. Tempering the incoming air reduces the need for heating, and so energy use.	+	Whole-house, or multi-room MVHR involves installing ductwork to each room, typically in ceiling voids, and running these ducts to a heat recovery unit, often located in the loft space. Air is continually extracted from rooms that might be warm and humid, such as bathrooms and kitchens. This is passed through a heat exchanger in the heat recovery unit where ‘waste’ heat is recovered from the air before it is rejected to the outside. The heat exchanger uses the recovered heat to ‘temper’ incoming fresh air that is used to supply the non-humid ‘habitable’ rooms such as bedrooms and living rooms. Tempering the incoming air reduces the need for heating, and so reduces energy use.

−	The standard, background level of ventilation can be boosted manually or automatically when bathrooms or kitchens are in use. The heat exchanger can be by-passed in warmer conditions so that the fresh supply air remains cool. Typically filters will be included in the system to remove potential pollutants such as pollen form the supply air.	+	The standard, background level of ventilation can be boosted manually or automatically when bathrooms or kitchens are in use. The heat exchanger can be by-passed in warmer conditions so that the fresh supply air remains cool. Typically filters will be included in the system to remove potential pollutants such as pollen and dust form the supply air.

−	Care must be taken when installing MHVR to ensure that ducts do not provide a flanking route for noise to transmit between spaces. It is also important to properly size and locate the heat recovery unit and ductwork so that any sound generated by the system is minimal.	+	Care must be taken when installing MHVR to ensure that ducts do not provide a flanking route for noise to transmit between spaces. It is also important to properly size and locate the heat recovery unit and ductwork so that any sound generated by the system itself is minimal.

−	~~MHVR~~ has become popular in new homes, but installation in existing properties can be disruptive due to the routing of ducts throughout the property.	+	MVHR has become popular in new homes, but installation in existing properties can be disruptive due to the routing of ducts throughout the property.

−	Regular maintenance is required to ensure that fans are operating correctly and filters remain clean.	+	Regular maintenance is required to ensure that fans are operating correctly and filters remain clean.

	= Find out more =		= Find out more =
Line 34:		Line 36:
	*Displacement ventilation.		*Displacement ventilation.
	*Domestic ventilation systems performance.		*Domestic ventilation systems performance.
		+	*Flanking sound.
	*Heat recovery.		*Heat recovery.
	*Humidity.		*Humidity.

Designing Buildings: moved Mechanical ventilation with heat recovery to Mechanical ventilation with heat recovery MVHR

2015-02-16T12:12:32Z

moved Mechanical ventilation with heat recovery to Mechanical ventilation with heat recovery MVHR

← Older revision

Revision as of 12:12, 16 February 2015