Stack effect - Revision history

Editor at 19:43, 20 June 2022

2022-06-20T19:43:20Z

← Older revision		Revision as of 19:43, 20 June 2022
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	NB: Stack ventilation can also refer to secondary ventilation stacks used to overcome air pressure changes in pipework in high-rise buildings. For more information see: Secondary ventilation stacks in tall buildings.		NB: Stack ventilation can also refer to secondary ventilation stacks used to overcome air pressure changes in pipework in high-rise buildings. For more information see: Secondary ventilation stacks in tall buildings.

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

	* Computational fluid dynamics.		* Computational fluid dynamics.

Designing Buildings at 08:30, 5 July 2021

2021-07-05T08:30:42Z

← Older revision		Revision as of 08:30, 5 July 2021
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	* Solar chimney.		* Solar chimney.
	* Thermal comfort.		* Thermal comfort.
		+	* Types of ventilation.
	* U-values.		* U-values.
	* Natural ventilation.		* Natural ventilation.

Designing Buildings at 08:04, 5 July 2021

2021-07-05T08:04:03Z

← Older revision		Revision as of 08:04, 5 July 2021
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	* Passive building design.		* Passive building design.
	* Secondary ventilation stacks in tall buildings.		* Secondary ventilation stacks in tall buildings.
		+	* Single-sided ventilation.
	* Solar chimney.		* Solar chimney.
	* Thermal comfort.		* Thermal comfort.

Designing Buildings at 09:47, 14 September 2020

2020-09-14T09:47:17Z

← Older revision		Revision as of 09:47, 14 September 2020
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	* Windcatcher.		* Windcatcher.

−	[[Category:Theory]] [[Category:Sustainability]]	+	[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:Theory]] [[Category:Sustainability]]

Editor at 14:03, 17 October 2018

2018-10-17T14:03:55Z

← Older revision		Revision as of 14:03, 17 October 2018
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	The pressure will vary through the height of the building, with the outside pressure being higher than the inside pressure at the bottom of the building, but the inside pressure being higher at the top. As a consequence, there will be a neutral plane, which is the level at which the internal and external pressure are equal. Above the neutral plane the internal air pressure will be positive and so air will tend to exhaust to the outside. Below the neutral plane, the internal air pressure will be negative and air will tend to be drawn into the building. This requires careful design to ensure that the neutral plane is above the spaces that need to be ventilated from the outside.		The pressure will vary through the height of the building, with the outside pressure being higher than the inside pressure at the bottom of the building, but the inside pressure being higher at the top. As a consequence, there will be a neutral plane, which is the level at which the internal and external pressure are equal. Above the neutral plane the internal air pressure will be positive and so air will tend to exhaust to the outside. Below the neutral plane, the internal air pressure will be negative and air will tend to be drawn into the building. This requires careful design to ensure that the neutral plane is above the spaces that need to be ventilated from the outside.

−	Stack ventilation is not appropriate for all building types, and as the stack effect requires that the internal temperature is higher than the outside temperature, it may not always provide a sufficient cooling effect by itself and additional mechanical cooling may be necessary. In particular, rooms adjoining the warmer part of the stack may experience poor ventilation and unwanted heat gains. In addition, there may be conflicts between the requirement for large unrestricted openings between the outside and the heart of the building, and requirements for security, privacy, noise control, fire compartmentation and so on.	+	Stack ventilation is not appropriate for all building types, and as the stack effect requires that the internal temperature is higher than the outside temperature, it may not always provide a sufficient cooling effect by itself and additional mechanical cooling may be necessary. In particular, rooms adjoining the warmer part of the stack may experience poor ventilation and unwanted heat gains. In addition, there may be conflicts between the requirement for large unrestricted openings between the outside and the heart of the building, and requirements for security, privacy, noise control, fire compartmentation, and so on.

	Designing natural ventilation can become extremely complex because of the interaction between cross ventilation and the stack effect as well as complex building geometries and complex distribution of openings. This can require computer analysis.		Designing natural ventilation can become extremely complex because of the interaction between cross ventilation and the stack effect as well as complex building geometries and complex distribution of openings. This can require computer analysis.
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	NB: Approved document F, Ventilation, defines 'passive stack ventilation' (PSV) as, ‘…a ventilation system using ducts from terminals in the ceiling of rooms to terminals on the roof that extract air to the outside by a combination of the natural stack effect and the pressure effects of wind passing over the roof of the building.’		NB: Approved document F, Ventilation, defines 'passive stack ventilation' (PSV) as, ‘…a ventilation system using ducts from terminals in the ceiling of rooms to terminals on the roof that extract air to the outside by a combination of the natural stack effect and the pressure effects of wind passing over the roof of the building.’

−	NB Stack ventilation can also refer to secondary ventilation stacks used to overcome air pressure changes in pipework in high-rise buildings. For more information see: Secondary ventilation stacks in tall buildings.	+	NB: Stack ventilation can also refer to secondary ventilation stacks used to overcome air pressure changes in pipework in high-rise buildings. For more information see: Secondary ventilation stacks in tall buildings.

−	~~= Find out more =~~	+	= Related articles on Designing Buildings Wiki =
−		+
−	=== Related articles on Designing Buildings Wiki ===	+

	* Computational fluid dynamics.		* Computational fluid dynamics.
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	* Dynamic thermal modelling of closed loop geothermal heat pump systems.		* Dynamic thermal modelling of closed loop geothermal heat pump systems.
	* Energy targets.		* Energy targets.
		+	* Face velocity.
	* Natural ventilation.		* Natural ventilation.
	* Passive building design.		* Passive building design.

Designing Buildings at 08:47, 23 July 2018

2018-07-23T08:47:07Z

← Older revision		Revision as of 08:47, 23 July 2018
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	* Natural ventilation.		* Natural ventilation.
	* Passive building design.		* Passive building design.
		+	* Secondary ventilation stacks in tall buildings.
	* Solar chimney.		* Solar chimney.
	* Thermal comfort.		* Thermal comfort.

Designing Buildings at 08:46, 23 July 2018

2018-07-23T08:46:51Z

← Older revision		Revision as of 08:46, 23 July 2018
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	NB: Approved document F, Ventilation, defines 'passive stack ventilation' (PSV) as, ‘…a ventilation system using ducts from terminals in the ceiling of rooms to terminals on the roof that extract air to the outside by a combination of the natural stack effect and the pressure effects of wind passing over the roof of the building.’		NB: Approved document F, Ventilation, defines 'passive stack ventilation' (PSV) as, ‘…a ventilation system using ducts from terminals in the ceiling of rooms to terminals on the roof that extract air to the outside by a combination of the natural stack effect and the pressure effects of wind passing over the roof of the building.’
		+
		+	NB Stack ventilation can also refer to secondary ventilation stacks used to overcome air pressure changes in pipework in high-rise buildings. For more information see: Secondary ventilation stacks in tall buildings.

	= Find out more =		= Find out more =

Editor at 12:37, 12 November 2017

2017-11-12T12:37:16Z

← Older revision		Revision as of 12:37, 12 November 2017
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	* Natural ventilation.		* Natural ventilation.
	* Ventilation.		* Ventilation.
		+	* Warm roof.
	* Windcatcher.		* Windcatcher.

	[[Category:Theory]] [[Category:Sustainability]]		[[Category:Theory]] [[Category:Sustainability]]

Editor at 12:27, 30 August 2017

2017-08-30T12:27:33Z

← Older revision		Revision as of 12:27, 30 August 2017
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−
	As air gets warmer it becomes less dense and so more buoyant. This means that warm air has a tendency to rise.		As air gets warmer it becomes less dense and so more buoyant. This means that warm air has a tendency to rise.

−	This effect can be used to naturally ventilate buildings. Cooler outside air is drawn into buildings at a lower level, it is warmed by sources of heat within the building (such as people, equipment, heating and solar gain), and then rises through the building to vent out at a higher level. A positive pressure area is created at the top of a building and negative pressure area at the bottom. This process can take place without mechanical assistance, simply by introducing openings at the bottom and the top of buildings. It is known as the stack effect or stack ventilation.	+	This effect can be used to naturally ventilate buildings. Cooler outside air is drawn into buildings at a lower level, it is warmed by sources of heat within the building (such as people, equipment, heating and solar gain), and then rises through the building to vent out at a higher level.
		+
		+	A positive pressure area is created at the top of a building and negative pressure area at the bottom. This process can take place without mechanical assistance, simply by introducing openings at the bottom and the top of buildings. It is known as the stack effect or stack ventilation.

	Stack ventilation can be particularly effective as a means of naturally ventilating tall buildings that include vertical spaces which rise throughout their height, for example buildings with central atriums. This can be useful in deep buildings, where cross ventilation may not be sufficient to penetrate to spaces in the heart of the building.		Stack ventilation can be particularly effective as a means of naturally ventilating tall buildings that include vertical spaces which rise throughout their height, for example buildings with central atriums. This can be useful in deep buildings, where cross ventilation may not be sufficient to penetrate to spaces in the heart of the building.

	The effectiveness of stack ventilation is influenced by:		The effectiveness of stack ventilation is influenced by:
−	*The effective area of openings.	+
−	*The height of the stack.	+	* The effective area of openings.
−	*The temperature difference between the bottom and the top of the stack.	+	* The height of the stack.
−	*Pressure differences outside the building.	+	* The temperature difference between the bottom and the top of the stack.
		+	* Pressure differences outside the building.

	The stack effect is a relatively weak force in many buildings (although it can be strong enough to fly a kite in large buildings) and so it may be necessary to have large openings with minimal resistance.		The stack effect is a relatively weak force in many buildings (although it can be strong enough to fly a kite in large buildings) and so it may be necessary to have large openings with minimal resistance.
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	Designing natural ventilation can become extremely complex because of the interaction between cross ventilation and the stack effect as well as complex building geometries and complex distribution of openings. This can require computer analysis.		Designing natural ventilation can become extremely complex because of the interaction between cross ventilation and the stack effect as well as complex building geometries and complex distribution of openings. This can require computer analysis.

−	NB Approved document F, Ventilation, defines 'passive stack ventilation' (PSV) as, ‘…a ventilation system using ducts from terminals in the ceiling of rooms to terminals on the roof that extract air to the outside by a combination of the natural stack effect and the pressure effects of wind passing over the roof of the building.’	+	NB: Approved document F, Ventilation, defines 'passive stack ventilation' (PSV) as, ‘…a ventilation system using ducts from terminals in the ceiling of rooms to terminals on the roof that extract air to the outside by a combination of the natural stack effect and the pressure effects of wind passing over the roof of the building.’

	= Find out more =		= Find out more =

	=== Related articles on Designing Buildings Wiki ===		=== Related articles on Designing Buildings Wiki ===
−	*Computational fluid dynamics.
−	*Cross ventilation.
−	*Dynamic thermal modelling of closed loop geothermal heat pump systems.
−	*Energy targets.
−	*Natural ventilation.
−	*Passive building design.
−	*Solar chimney.
−	*Thermal comfort.
−	*U-values.
−	*Natural ventilation.
−	*Ventilation.

−	[[Category:Theory]]	+	* Computational fluid dynamics.
−	[[Category:Sustainability]]	+	* Cross ventilation.
		+	* Dynamic thermal modelling of closed loop geothermal heat pump systems.
		+	* Energy targets.
		+	* Natural ventilation.
		+	* Passive building design.
		+	* Solar chimney.
		+	* Thermal comfort.
		+	* U-values.
		+	* Natural ventilation.
		+	* Ventilation.
		+	* Windcatcher.
		+
		+	[[Category:Theory]] [[Category:Sustainability]]

Designing Buildings at 07:48, 1 July 2015

2015-07-01T07:48:43Z

← Older revision		Revision as of 07:48, 1 July 2015
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	Designing natural ventilation can become extremely complex because of the interaction between cross ventilation and the stack effect as well as complex building geometries and complex distribution of openings. This can require computer analysis.		Designing natural ventilation can become extremely complex because of the interaction between cross ventilation and the stack effect as well as complex building geometries and complex distribution of openings. This can require computer analysis.
		+
		+	NB Approved document F, Ventilation, defines 'passive stack ventilation' (PSV) as, ‘…a ventilation system using ducts from terminals in the ceiling of rooms to terminals on the roof that extract air to the outside by a combination of the natural stack effect and the pressure effects of wind passing over the roof of the building.’

	= Find out more =		= Find out more =