Cross ventilation - Revision history

46.114.37.179 at 15:26, 16 May 2022

2022-05-16T15:26:26Z

← Older revision		Revision as of 15:26, 16 May 2022
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	* Air infiltration testing.		* Air infiltration testing.
	* Approved Document F.		* Approved Document F.
		+	* Approved Document O.
	* BREEAM Potential for natural ventilation.		* BREEAM Potential for natural ventilation.
	* Building services.		* Building services.

46.114.37.179 at 15:01, 16 May 2022

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	In straight-forward buildings, cross ventilation can often be designed by following rules of thumb for the openable area required for a given floor area, depending on the nature of the space and occupancy. The situation becomes more complicated when cross ventilation is combined with the stack effect or mechanical systems, and thermal mass and solar gain are taken into consideration. Modelling this behaviour can become extremely complicated, sometimes requiring the use of local weather data, software such as computational fluid dynamics (CFD) programs and even wind tunnel testing.		In straight-forward buildings, cross ventilation can often be designed by following rules of thumb for the openable area required for a given floor area, depending on the nature of the space and occupancy. The situation becomes more complicated when cross ventilation is combined with the stack effect or mechanical systems, and thermal mass and solar gain are taken into consideration. Modelling this behaviour can become extremely complicated, sometimes requiring the use of local weather data, software such as computational fluid dynamics (CFD) programs and even wind tunnel testing.

−	Ventilation in buildings is regulated by [[Approved_Document_F\|Part F]] of the building regulations.	+	Ventilation in buildings is regulated by [[Approved_Document_F\|Part F]] of the building regulations and soon to be Part O.

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

	* Air infiltration testing.		* Air infiltration testing.

Designing Buildings: Reverted edits by 155.205.200.199 (talk) to last revision by Designing Buildings

2022-04-01T05:21:23Z

Reverted edits by 155.205.200.199 (talk) to last revision by Designing Buildings

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Designing Buildings at 10:37, 16 December 2021

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	Natural ventilation can be wind-driven (or wind-induced), or it can be buoyancy-driven ‘stack’ ventilation. For more information about buoyancy-driven ‘stack’ ventilation, see Stack effect.		Natural ventilation can be wind-driven (or wind-induced), or it can be buoyancy-driven ‘stack’ ventilation. For more information about buoyancy-driven ‘stack’ ventilation, see Stack effect.
		+
		+	Approved Document O: Overheating, published by HM Government in 2021, defines cross-ventilation as: ‘The ability to ventilate using openings on opposite façades of a dwelling. Having openings on façades that are not opposite is not allowing cross-ventilation, e.g. in a corner flat.’

	Cross ventilation occurs where there are pressure differences between one side of a building and the other. Typically, this is a wind-driven effect in which air is drawn into the building on the high pressure windward side and is drawn out of the building on the low pressure leeward side. Wind can also drive single-sided ventilation and vertical ventilation.		Cross ventilation occurs where there are pressure differences between one side of a building and the other. Typically, this is a wind-driven effect in which air is drawn into the building on the high pressure windward side and is drawn out of the building on the low pressure leeward side. Wind can also drive single-sided ventilation and vertical ventilation.

Designing Buildings at 08:28, 5 July 2021

2021-07-05T08:28:16Z

← Older revision		Revision as of 08:28, 5 July 2021
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	* Stack effect.		* Stack effect.
	* Thermal comfort.		* Thermal comfort.
		+	* Types of ventilation.
	* [[UV_disinfection_of_building_air_to_remove_harmful_bacteria_and_viruses\|UV disinfection of building air to remove harmful bacteria and viruses]].		* [[UV_disinfection_of_building_air_to_remove_harmful_bacteria_and_viruses\|UV disinfection of building air to remove harmful bacteria and viruses]].
	* Ventilation.		* Ventilation.

	[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:Design]]		[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:Design]]

Designing Buildings at 08:04, 5 July 2021

2021-07-05T08:04:35Z

← Older revision		Revision as of 08:04, 5 July 2021
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	* Passive building design.		* Passive building design.
	* Dew point.		* Dew point.
		+	* Single-sided ventilation.
	* Solar chimney.		* Solar chimney.
	* Stack effect.		* Stack effect.

Simon Baxter at 09:38, 2 October 2020

2020-10-02T09:38:50Z

← Older revision		Revision as of 09:38, 2 October 2020
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	* Stack effect.		* Stack effect.
	* Thermal comfort.		* Thermal comfort.
		+	* [[UV_disinfection_of_building_air_to_remove_harmful_bacteria_and_viruses\|UV disinfection of building air to remove harmful bacteria and viruses]].
	* Ventilation.		* Ventilation.

	[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:Design]]		[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:Design]]

Designing Buildings at 08:40, 4 September 2020

2020-09-04T08:40:09Z

← Older revision		Revision as of 08:40, 4 September 2020
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	* Ventilation.		* Ventilation.

−	[[Category:Design]]	+	[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:Design]]

Editor at 13:34, 6 November 2018

2018-11-06T13:34:18Z

← Older revision		Revision as of 13:34, 6 November 2018
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−	[[File:Crossventilation.jpg]]	+	[[File:Crossventilation.jpg\|link=File:Crossventilation.jpg]]

	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:
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	Whereas cross ventilation is generally more straight-forward to provide than stack ventilation, it has the disadvantage that it tends to be least effective on hot, still days, when it is needed most. In addition, it is generally only suitable for narrow buildings.		Whereas cross ventilation is generally more straight-forward to provide than stack ventilation, it has the disadvantage that it tends to be least effective on hot, still days, when it is needed most. In addition, it is generally only suitable for narrow buildings.

−	If there are windows on both sides, then cross ventilation might be suitable for buildings where the width is up to five times the floor to ceiling height. Where there are only openings on one side, wind-driven ventilation might be suitable for buildings where the width is up to 2.5 times the floor to ceiling height.	+	If there are windows on both sides, then cross ventilation might be suitable for buildings where the width is up to five times the floor-to-ceiling height. Where there are only openings on one side, wind-driven ventilation might be suitable for buildings where the width is up to 2.5 times the floor to ceiling height.

	Beyond this, providing sufficient fresh air creates draughts close to openings, and additional design elements such as internal courtyards are necessary, or the inclusion of elements such as atrium that combine cross ventilation and stack effects, or mechanically assisted ventilation.		Beyond this, providing sufficient fresh air creates draughts close to openings, and additional design elements such as internal courtyards are necessary, or the inclusion of elements such as atrium that combine cross ventilation and stack effects, or mechanically assisted ventilation.
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	* Internal partitions block air paths.		* Internal partitions block air paths.

−	Some of these issues can be avoided or mitigated by careful siting and design of buildings. For example, louvres can be used where ventilation is required, but a window is not, and ducts or openings can be provided in internal partitions, although these will only be effective if there is sufficient open area, and there may be problems with acoustic separation.	+	Some of these issues can be avoided or mitigated by careful siting and design of buildings. For example, [[Louvre_window\|louvres]] can be used where ventilation is required, but a window is not, and ducts or openings can be provided in internal partitions, although these will only be effective if there is sufficient open area, and there may be problems with acoustic separation.

	Cross ventilation can be problematic during the winter when windows may be closed, particularly in modern buildings which tend to be highly sealed. Trickle ventilation, or crack settings on windows can be provided to ensure there is adequate background ventilation. Trickle ventilators can be self-balancing, with the size of the open area depending on the air pressure difference across it.		Cross ventilation can be problematic during the winter when windows may be closed, particularly in modern buildings which tend to be highly sealed. Trickle ventilation, or crack settings on windows can be provided to ensure there is adequate background ventilation. Trickle ventilators can be self-balancing, with the size of the open area depending on the air pressure difference across it.