Constant air volume CAV - Revision history

Designing Buildings at 06:33, 4 August 2022

2022-08-04T06:33:48Z

← Older revision		Revision as of 06:33, 4 August 2022
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	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.

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

	* Air conditioning.		* Air conditioning.
	* Building services.		* Building services.
	* Chiller unit.		* Chiller unit.
−	* ~~Computational fluid dynamics~~.	+	* Constant volume system.
	* Cross ventilation.		* Cross ventilation.
	* Dew point.		* Dew point.

Designing Buildings at 09:04, 8 October 2020

2020-10-08T09:04:31Z

← Older revision		Revision as of 09:04, 8 October 2020
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	* Volume.		* Volume.

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

Editor at 15:32, 12 November 2018

2018-11-12T15:32:06Z

← Older revision		Revision as of 15:32, 12 November 2018
Line 1:		Line 1:
−
	Ventilation is necessary in buildings to remove ‘stale’ air and replace it with ‘fresh’ air. This helps to:		Ventilation is necessary in buildings to remove ‘stale’ air and replace it with ‘fresh’ air. This helps to:
−	*Moderate internal temperatures.
−	*Replenish oxygen.
−	*Reduce the accumulation of moisture, odours, bacteria, dust, carbon dioxide, smoke and other contaminants that can build up during occupied periods.
−	*Create air movement, which improves the comfort of occupants.

−	Very broadly, ventilation in buildings can be classified as ‘natural’ or ‘mechanical’. Mechanical ventilation systems can also include heating, cooling, humidity control and air filtration. These functions are often described collectively as HVAC (Heating Ventilation and Air Conditioning).	+	* Moderate internal temperatures.
		+	* Replenish oxygen.
		+	* Reduce the accumulation of moisture, odours, bacteria, dust, carbon dioxide, smoke and other contaminants that can build up during occupied periods.
		+	* Create air movement, which improves the comfort of occupants.
		+
		+	Very broadly, ventilation in buildings can be classified as ‘natural’ or ‘mechanical’. Mechanical ventilation systems can also include heating, cooling, humidity control and air filtration. These functions are often described collectively as [[Heating_ventilation_and_air_conditioning_HVAC\|HVAC (Heating Ventilation and Air Conditioning)]].

	Within these systems, ventilation and temperature can be regulated either by:		Within these systems, ventilation and temperature can be regulated either by:
−	*Variable air volume (VAV), in which the temperature of the supply air remains constant, but the volume varies (also known as variable volume, constant temperature VV-CT).	+
−	*Constant air volume (CAV) in which the volume of air supply remains constant, but the temperature varies (also known as constant volume, variable temperature CV-VT, or constant volume CV).	+	* Variable air volume (VAV), in which the temperature of the supply air remains constant, but the volume varies (also known as variable volume, constant temperature VV-CT).
−	*Variable volume, variable temperature (VV-VT sometimes referred to as variable volume and temperature - VVT).	+	* Constant air volume (CAV) in which the volume of air supply remains constant, but the temperature varies (also known as constant volume, variable temperature CV-VT, or constant volume CV).
		+	* Variable volume, variable temperature (VV-VT sometimes referred to as variable volume and temperature - VVT).

	Constant air volume (CAV) systems are becoming less common in new buildings as VAV systems tend to provide closer control of air temperature and require lower fan speeds, as a result of which they can use less energy and generate less noise. However, CAV systems are still used in small and medium-sized premises with straight-forward HVAC requirements, as they can be relatively simple to install, can have a lower capital cost and tend to be reliable.		Constant air volume (CAV) systems are becoming less common in new buildings as VAV systems tend to provide closer control of air temperature and require lower fan speeds, as a result of which they can use less energy and generate less noise. However, CAV systems are still used in small and medium-sized premises with straight-forward HVAC requirements, as they can be relatively simple to install, can have a lower capital cost and tend to be reliable.
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	Alternatively, 'mixed-air' or 'dual-duct' systems can provide both heated and cooled air, the proportions of which are regulated locally in mixing boxes. This might be appropriate where there are significant differences in thermal demand. Air is supplied at the lowest and highest temperatures required and then mixed locally as necessary.		Alternatively, 'mixed-air' or 'dual-duct' systems can provide both heated and cooled air, the proportions of which are regulated locally in mixing boxes. This might be appropriate where there are significant differences in thermal demand. Air is supplied at the lowest and highest temperatures required and then mixed locally as necessary.

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

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

−	~~=== Related articles on Designing Buildings Wiki ===~~	+	* Air conditioning.
−	*Air conditioning.	+	* Building services.
−	*Building services.	+	* Chiller unit.
−	*Chiller unit.	+	* Computational fluid dynamics.
−	*Computational fluid dynamics.	+	* Cross ventilation.
−	*Cross ventilation.	+	* Dew point.
−	*Dew point.	+	* Humidity.
−	*Humidity.	+	* Interstitial condensation.
−	*Interstitial condensation.	+	* Mechanical ventilation.
−	*Mechanical ventilation.	+	* Natural ventilation.
−	*Natural ventilation.	+	* Passive building design.
−	*Passive building design.	+	* Solar chimney.
−	*Solar chimney.	+	* Stack effect.
−	*Stack effect.	+	* Thermal comfort.
−	*Thermal comfort.	+	* Variable air volume.
−	*Variable air volume.	+	* Ventilation.
−	*Ventilation.	+	* Volume.

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

Designing Buildings at 13:43, 14 November 2014

2014-11-14T13:43:42Z

← Older revision		Revision as of 13:43, 14 November 2014
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	= '''Find out more''' =		= '''Find out more''' =

−	~~'''~~Related articles on Designing Buildings Wiki~~'''~~	+	=== Related articles on Designing Buildings Wiki ===
	*Air conditioning.		*Air conditioning.
	*Building services.		*Building services.

Designing Buildings at 10:36, 17 October 2014

2014-10-17T10:36:29Z

← Older revision		Revision as of 10:36, 17 October 2014
Line 30:		Line 30:
	*Air conditioning.		*Air conditioning.
	*Building services.		*Building services.
		+	*Chiller unit.
	*Computational fluid dynamics.		*Computational fluid dynamics.
	*Cross ventilation.		*Cross ventilation.

Designing Buildings at 07:51, 13 October 2014

2014-10-13T07:51:22Z

← Older revision		Revision as of 07:51, 13 October 2014
Line 15:		Line 15:
	Constant air volume (CAV) systems are becoming less common in new buildings as VAV systems tend to provide closer control of air temperature and require lower fan speeds, as a result of which they can use less energy and generate less noise. However, CAV systems are still used in small and medium-sized premises with straight-forward HVAC requirements, as they can be relatively simple to install, can have a lower capital cost and tend to be reliable.		Constant air volume (CAV) systems are becoming less common in new buildings as VAV systems tend to provide closer control of air temperature and require lower fan speeds, as a result of which they can use less energy and generate less noise. However, CAV systems are still used in small and medium-sized premises with straight-forward HVAC requirements, as they can be relatively simple to install, can have a lower capital cost and tend to be reliable.

−	They are particularly common in simple systems where fan coil units are supplied with a constant volume of ‘fresh’ air.	+	They are particularly common in simple systems where fan coil units are supplied with a constant volume of ‘fresh’ air.

	Simple, single-duct CAV systems which supply air at a single temperature and constant volume might be suitable for a large space with simple, uniform thermal demand, such as a gymnasium.		Simple, single-duct CAV systems which supply air at a single temperature and constant volume might be suitable for a large space with simple, uniform thermal demand, such as a gymnasium.

−	This system can be enhanced by reheating the supply air in CAV terminal units to provide additional local control. This might be appropriate where there are some minor local variations to thermal demand. In this case, air is supplied to the system at the lowest temperature required and then its temperature increased as necessary locally.	+	This system can be enhanced by reheating the supply air in CAV terminal units to provide additional local control. This might be appropriate where there are some minor local variations to thermal demand. In this case, air is supplied to the system at the lowest temperature required and then its temperature is increased as necessary locally.

−	Alternatively, mixed-air or dual-duct systems can provide both heated and cooled air, the proportions of which are regulated locally in mixing boxes. This might be appropriate where there are significant differences in thermal demand. Air is supplied at the lowest and highest temperatures required and then mixed locally as necessary.	+	Alternatively, 'mixed-air' or 'dual-duct' systems can provide both heated and cooled air, the proportions of which are regulated locally in mixing boxes. This might be appropriate where there are significant differences in thermal demand. Air is supplied at the lowest and highest temperatures required and then mixed locally as necessary.

	Ventilation in buildings is regulated by Part F of the building regulations.		Ventilation in buildings is regulated by Part F of the building regulations.

Designing Buildings at 07:48, 13 October 2014

2014-10-13T07:48:49Z

Designing Buildings: moved Constant air volume to Constant air volume CAV

2014-10-13T07:42:10Z

moved Constant air volume to Constant air volume CAV

← Older revision

Revision as of 07:42, 13 October 2014

Designing Buildings: Created page with " Ventilation is necessary in buildings to remove ‘stale’ air and replace it with ‘fresh’ air: Helping to moderate internal temperatures. Replenishing oxygen. *Reducing ..."

2014-10-13T07:42:00Z

Created page with " Ventilation is necessary in buildings to remove ‘stale’ air and replace it with ‘fresh’ air: *Helping to moderate internal temperatures. *Replenishing oxygen. *Reducing ..."

New page

Ventilation is necessary in buildings to remove ‘stale’ air and replace it with ‘fresh’ air:
*Helping to moderate internal temperatures.
*Replenishing oxygen.
*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’. Mechanical ventilation systems can also include heating, cooling, humidity control and air filtration. These functions are often described collectively as HVAC (Heating Ventilation and Air Conditioning).

Within these systems, ventilation and temperature can be regulated either by:
*Variable air volume (VAV), in which the temperature of the supply air remains constant, but the volume varies (also known as variable volume, constant temperature VV-CT).
*Constant air volume (CAV) in which the volume of air supply remains constant, but the temperature varies (also known as constant volume, variable temperature CV-VT, or Constant Volume (CV)).
*Variable volume, variable temperature (VV-VT sometimes referred to as variable volume and temperature - VVT).

CAV is becoming less common in new buildings as VAV systems tend to provide closer control of air temperature than CAV systems and require lower fan speeds, as a result of which they can use less energy and generate less noise. However, they are still used in small and medium sized premises with straight forward HVAC requirements, as they can be relatively simple to install, have a relatively lower capital cost and tend to be reliable.

They are particularly common in simple systems where fan coil units are supplied with a constant volume of ‘fresh’ air. Because the volume is constant, air pressure is constant throughout the system.

Simple, single duct CAV systems which supply air at a single temperature and constant volume to an entire ‘zone’ might be suitable for a large space with simple, uniform thermal demand, such as a gymnasium.

This system can be enhanced by reheating in CAV terminal units to provide additional local control. This might be appropriate where there are some minor local variations to thermal demand. In this case, air is supplied at the lowest temperature required and then its temperature increased as necessary locally.

Alternatively, mixed air or dual duct systems can provide both heated and cooled air, the proportions of which are regulated locally in mixing boxes. This might be appropriate where there are significant differences in thermal demand throughout a zone. Air is supplied at the lowest and highest temperatures required and then mixed locally as necessary.

Ventilation in buildings is regulated by Part F of the building regulations.

= '''Find out more''' =

'''Related articles on Designing Buildings Wiki'''
*Air conditioning.
*Building services.
*Computational fluid dynamics.
*Cross ventilation.
*Dew point.
*Humidity.
*Interstitial condensation.
*Mechanical ventilation.
*Natural ventilation.
*Passive building design.
*Solar chimney.
*Stack effect.
*Thermal comfort.
*Variable air volume.
*Ventilation.

[[Category:Products_/_components]]

← Older revision		Revision as of 07:48, 13 October 2014
Line 1:		Line 1:

−	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. This helps to:
−	*~~Helping to moderate~~ internal temperatures.	+	*Moderate internal temperatures.
−	*~~Replenishing~~ oxygen.	+	*Replenish oxygen.
−	*~~Reducing~~ the accumulation of moisture, odours, bacteria, dust, carbon dioxide, smoke and other contaminants that can build up during occupied periods.	+	*Reduce 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.	+	*Create air movement, which improves the comfort of occupants.

	Very broadly, ventilation in buildings can be classified as ‘natural’ or ‘mechanical’. Mechanical ventilation systems can also include heating, cooling, humidity control and air filtration. These functions are often described collectively as HVAC (Heating Ventilation and Air Conditioning).		Very broadly, ventilation in buildings can be classified as ‘natural’ or ‘mechanical’. Mechanical ventilation systems can also include heating, cooling, humidity control and air filtration. These functions are often described collectively as HVAC (Heating Ventilation and Air Conditioning).
Line 10:		Line 10:
	Within these systems, ventilation and temperature can be regulated either by:		Within these systems, ventilation and temperature can be regulated either by:
	*Variable air volume (VAV), in which the temperature of the supply air remains constant, but the volume varies (also known as variable volume, constant temperature VV-CT).		*Variable air volume (VAV), in which the temperature of the supply air remains constant, but the volume varies (also known as variable volume, constant temperature VV-CT).
−	*Constant air volume (CAV) in which the volume of air supply remains constant, but the temperature varies (also known as constant volume, variable temperature CV-VT, or ~~Constant Volume (~~CV)).	+	*Constant air volume (CAV) in which the volume of air supply remains constant, but the temperature varies (also known as constant volume, variable temperature CV-VT, or constant volume CV).
	*Variable volume, variable temperature (VV-VT sometimes referred to as variable volume and temperature - VVT).		*Variable volume, variable temperature (VV-VT sometimes referred to as variable volume and temperature - VVT).

−	CAV is becoming less common in new buildings as VAV systems tend to provide closer control of air temperature ~~than CAV systems~~ and require lower fan speeds, as a result of which they can use less energy and generate less noise. However, ~~they~~ are still used in small and medium sized premises with straight forward HVAC requirements, as they can be relatively simple to install, have a ~~relatively~~ lower capital cost and tend to be reliable.	+	Constant air volume (CAV) systems are becoming less common in new buildings as VAV systems tend to provide closer control of air temperature and require lower fan speeds, as a result of which they can use less energy and generate less noise. However, CAV systems are still used in small and medium-sized premises with straight-forward HVAC requirements, as they can be relatively simple to install, can have a lower capital cost and tend to be reliable.

−	They are particularly common in simple systems where fan coil units are supplied with a constant volume of ‘fresh’ air~~. Because the volume is constant, air pressure is constant throughout the system~~.	+	They are particularly common in simple systems where fan coil units are supplied with a constant volume of ‘fresh’ air.

−	Simple, single duct CAV systems which supply air at a single temperature and constant volume ~~to an entire ‘zone’~~ might be suitable for a large space with simple, uniform thermal demand, such as a gymnasium.	+	Simple, single-duct CAV systems which supply air at a single temperature and constant volume might be suitable for a large space with simple, uniform thermal demand, such as a gymnasium.

−	This system can be enhanced by reheating in CAV terminal units to provide additional local control. This might be appropriate where there are some minor local variations to thermal demand. In this case, air is supplied at the lowest temperature required and then its temperature increased as necessary locally.	+	This system can be enhanced by reheating the supply air in CAV terminal units to provide additional local control. This might be appropriate where there are some minor local variations to thermal demand. In this case, air is supplied to the system at the lowest temperature required and then its temperature increased as necessary locally.

−	Alternatively, mixed air or dual duct systems can provide both heated and cooled air, the proportions of which are regulated locally in mixing boxes. This might be appropriate where there are significant differences in thermal demand ~~throughout a zone~~. Air is supplied at the lowest and highest temperatures required and then mixed locally as necessary.	+	Alternatively, mixed-air or dual-duct systems can provide both heated and cooled air, the proportions of which are regulated locally in mixing boxes. This might be appropriate where there are significant differences in thermal demand. Air is supplied at the lowest and highest temperatures required and then mixed locally as necessary.

	Ventilation in buildings is regulated by Part F of the building regulations.		Ventilation in buildings is regulated by Part F of the building regulations.