Chiller units - Revision history

Designing Buildings at 10:51, 16 December 2025

2025-12-16T10:51:37Z

← Older revision		Revision as of 10:51, 16 December 2025
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	* Ventilation.		* Ventilation.

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

Editor at 07:20, 3 May 2022

2022-05-03T07:20:48Z

← Older revision		Revision as of 07:20, 3 May 2022
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	* Absorption chiller.		* Absorption chiller.
	* Absorption refrigeration.		* Absorption refrigeration.
		+	* Air conditioning inflation and supply chain crisis
	* Air conditioning.		* Air conditioning.
	* Air handling unit.		* Air handling unit.

Editor at 18:37, 25 January 2022

2022-01-25T18:37:48Z

← Older revision		Revision as of 18:37, 25 January 2022
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	* Heat recovery.		* Heat recovery.
	* HVAC.		* HVAC.
		+	* Hydrochlorofluorocarbons HCFCs.
	* Passive building design.		* Passive building design.
	* Refrigerants.		* Refrigerants.

Editor at 18:28, 17 December 2021

2021-12-17T18:28:11Z

← Older revision		Revision as of 18:28, 17 December 2021
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	Typically in heating, ventilation and air conditioning systems, chiller units produce chilled water that is piped to air handling units (or fan coil units) where it is used to cool the air that ventilates the building. The ‘warmed’ water is then returned to the chiller unit to be re-cooled. The process of cooling ventilation air will also reduce its humidity.		Typically in heating, ventilation and air conditioning systems, chiller units produce chilled water that is piped to air handling units (or fan coil units) where it is used to cool the air that ventilates the building. The ‘warmed’ water is then returned to the chiller unit to be re-cooled. The process of cooling ventilation air will also reduce its humidity.

−	Air handling units may also include a heating coil for times when heating rather than cooling is required. In some situations, air that has already been cooled will be re-heated (typically in simple, single duct constant air ~~voume~~ (VAC) systems). Whilst this may seem wasteful, in buildings where there are some minor local variations in thermal demand it can be more economic than it would be to provide two separate air ducting networks.	+	Air handling units may also include a heating coil for times when heating rather than cooling is required. In some situations, air that has already been cooled will be re-heated (typically in simple, single duct constant air volume (VAC) systems). Whilst this may seem wasteful, in buildings where there are some minor local variations in thermal demand it can be more economic than it would be to provide two separate air ducting networks.

	Chilled water might be supplied to other components, such as chilled beams, chilled ceilings and so on.		Chilled water might be supplied to other components, such as chilled beams, chilled ceilings and so on.
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	An alternative system supplies the refrigerant itself (rather than chilled water) to terminal units supplying different thermal zones. Variable refrigerant flow (VRF) systems use a single external condensing unit and multiple internal evaporators and can be more efficient, more compact and offer greater flexibility than other HVAC systems. See Variable refrigerant flow for more information.		An alternative system supplies the refrigerant itself (rather than chilled water) to terminal units supplying different thermal zones. Variable refrigerant flow (VRF) systems use a single external condensing unit and multiple internal evaporators and can be more efficient, more compact and offer greater flexibility than other HVAC systems. See Variable refrigerant flow for more information.

−	Some refrigerants have both ozone depletion potential (ODP) and global warming potential (GWP), and as a consequence refrigerants such as ~~CFC’s~~ (chlorofluorocarbons) are banned. New equipment using HCFCs ((hydrochlorofluorocarbons such as R22 and R408A) was banned in 2001 (2004 for small systems), and the use of virgin ~~HCFC's~~ was banned in 2010, when it also became illegal to manufacture HCFC refrigerants or for suppliers to keep them in stock. From January 1st 2015 the use of ~~HCFC’s~~ was prohibited in any form, even for maintenance. The use of ~~HFC's~~ (hydrofluorocarbons, including 417A, 422A, 422D, 424A, 427A, 428A and 434A) continues to be permitted. Other refrigerants include, ammonia (common in absorption refrigeration), carbon dioxide and non-halogenated hydrocarbons.	+	Some refrigerants have both ozone depletion potential (ODP) and global warming potential (GWP), and as a consequence refrigerants such as CFCs (chlorofluorocarbons) are banned. New equipment using HCFCs ((hydrochlorofluorocarbons such as R22 and R408A) was banned in 2001 (2004 for small systems), and the use of virgin HCFCs was banned in 2010, when it also became illegal to manufacture HCFC refrigerants or for suppliers to keep them in stock. From January 1st 2015 the use of HCFCs was prohibited in any form, even for maintenance. The use of HFCs (hydrofluorocarbons, including 417A, 422A, 422D, 424A, 427A, 428A and 434A) continues to be permitted. Other refrigerants include, ammonia (common in absorption refrigeration), carbon dioxide and non-halogenated hydrocarbons.

	It is important that the design of HVAC systems is considered as a part of the overall design process for the building, and not seen as an add on at the end. It is also important that HVAC systems are regularly maintained to ensure optimum performance and occupant comfort.		It is important that the design of HVAC systems is considered as a part of the overall design process for the building, and not seen as an add on at the end. It is also important that HVAC systems are regularly maintained to ensure optimum performance and occupant comfort.
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	* Air handling unit.		* Air handling unit.
	* Chilled beam.		* Chilled beam.
		+	* Chlorofluorocarbons CFCs.
	* Constant air volume.		* Constant air volume.
	* Fan coil unit.		* Fan coil unit.

Designing Buildings at 09:30, 15 November 2021

2021-11-15T09:30:42Z

← Older revision		Revision as of 09:30, 15 November 2021
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	It is important that the design of HVAC systems is considered as a part of the overall design process for the building, and not seen as an add on at the end. It is also important that HVAC systems are regularly maintained to ensure optimum performance and occupant comfort.		It is important that the design of HVAC systems is considered as a part of the overall design process for the building, and not seen as an add on at the end. It is also important that HVAC systems are regularly maintained to ensure optimum performance and occupant comfort.

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

		+	* Absorption chiller.
	* Absorption refrigeration.		* Absorption refrigeration.
	* Air conditioning.		* Air conditioning.

Designing Buildings at 06:48, 20 December 2020

2020-12-20T06:48:20Z

← Older revision		Revision as of 06:48, 20 December 2020
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	It is important that the design of HVAC systems is considered as a part of the overall design process for the building, and not seen as an add on at the end. It is also important that HVAC systems are regularly maintained to ensure optimum performance and occupant comfort.		It is important that the design of HVAC systems is considered as a part of the overall design process for the building, and not seen as an add on at the end. It is also important that HVAC systems are regularly maintained to ensure optimum performance and occupant comfort.

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

	* Absorption refrigeration.		* Absorption refrigeration.

Designing Buildings at 12:52, 1 October 2020

2020-10-01T12:52:04Z

← Older revision		Revision as of 12:52, 1 October 2020
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−
−	~~To help develop this article, click ‘Edit this article’ above.~~
−
−	~~----~~
−
	Chillers are used in buildings to provide cooling. This is typically for heating, ventilation and air conditioning (HVAC) systems providing thermal comfort for occupants, but they can also be used to provide cooling for industrial processes.		Chillers are used in buildings to provide cooling. This is typically for heating, ventilation and air conditioning (HVAC) systems providing thermal comfort for occupants, but they can also be used to provide cooling for industrial processes.

	Chillers remove heat from a liquid through a refrigeration cycle in a process that is essentially the same as that used to cool domestic fridges. They can work on compression or absorption:		Chillers remove heat from a liquid through a refrigeration cycle in a process that is essentially the same as that used to cool domestic fridges. They can work on compression or absorption:
−	*In compression systems, a liquid refrigerant with a low boiling point absorbs heat from water returning from the building and boils in an evaporator to form a gas. The gas is then compressed, which increases its temperature further. The gas is then condensed, releasing its latent heat which is rejected to the outside. The process then repeats.	+
−	*Absorption refrigeration works on a similar basis, with a refrigerant that boils at low temperature and pressure, however, in this case, the refrigerant gas is then absorbed in a solution which is then heated in a ‘generator’ so that the refrigerant evaporates again, but this time at a higher pressure and temperature. The gas is then condensed, releasing its latent heat which is rejected to the outside. The process then repeats.	+	* In compression systems, a liquid refrigerant with a low boiling point absorbs heat from water returning from the building and boils in an evaporator to form a gas. The gas is then compressed, which increases its temperature further. The gas is then condensed, releasing its latent heat which is rejected to the outside. The process then repeats.
		+	* Absorption refrigeration works on a similar basis, with a refrigerant that boils at low temperature and pressure, however, in this case, the refrigerant gas is then absorbed in a solution which is then heated in a ‘generator’ so that the refrigerant evaporates again, but this time at a higher pressure and temperature. The gas is then condensed, releasing its latent heat which is rejected to the outside. The process then repeats.

	The rejection of heat from chiller units can be achieved by:		The rejection of heat from chiller units can be achieved by:
−	*Air cooling, which rejects heat to the outside air by circulating it through the condenser.	+
−	*Evaporative cooing, which uses the addition of a water mist to the air to enhance the cooing effect.	+	* Air cooling, which rejects heat to the outside air by circulating it through the condenser.
−	*Water cooling, which is generally suited to large systems and requires connection to cooling towers.	+	* Evaporative cooing, which uses the addition of a water mist to the air to enhance the cooing effect.
		+	* Water cooling, which is generally suited to large systems and requires connection to cooling towers.

	Heat recovery can be used to allow the rejected heat from chiller units to be re-used for space heating or to provide hot water.		Heat recovery can be used to allow the rejected heat from chiller units to be re-used for space heating or to provide hot water.
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	An alternative system supplies the refrigerant itself (rather than chilled water) to terminal units supplying different thermal zones. Variable refrigerant flow (VRF) systems use a single external condensing unit and multiple internal evaporators and can be more efficient, more compact and offer greater flexibility than other HVAC systems. See Variable refrigerant flow for more information.		An alternative system supplies the refrigerant itself (rather than chilled water) to terminal units supplying different thermal zones. Variable refrigerant flow (VRF) systems use a single external condensing unit and multiple internal evaporators and can be more efficient, more compact and offer greater flexibility than other HVAC systems. See Variable refrigerant flow for more information.

−	Some refrigerants have both ozone depletion potential (ODP) and global warming potential (GWP), and as a consequence refrigerants such as CFC’s (chlorofluorocarbons) are banned. New equipment using HCFCs ((hydrochlorofluorocarbons such as R22 and R408A) was banned in 2001 (2004 for small systems), and the use of virgin HCFC's was banned in 2010, when it also became illegal to manufacture HCFC refrigerants or for suppliers to keep them in stock. From January ~~1<sup>st</sup>~~ 2015 the use of HCFC’s was prohibited in any form, even for maintenance. The use of HFC's (hydrofluorocarbons, including 417A, 422A, 422D, 424A, 427A, 428A and 434A) continues to be permitted. Other refrigerants include, ammonia (common in absorption refrigeration), carbon dioxide and non-halogenated hydrocarbons.	+	Some refrigerants have both ozone depletion potential (ODP) and global warming potential (GWP), and as a consequence refrigerants such as CFC’s (chlorofluorocarbons) are banned. New equipment using HCFCs ((hydrochlorofluorocarbons such as R22 and R408A) was banned in 2001 (2004 for small systems), and the use of virgin HCFC's was banned in 2010, when it also became illegal to manufacture HCFC refrigerants or for suppliers to keep them in stock. From January 1st 2015 the use of HCFC’s was prohibited in any form, even for maintenance. The use of HFC's (hydrofluorocarbons, including 417A, 422A, 422D, 424A, 427A, 428A and 434A) continues to be permitted. Other refrigerants include, ammonia (common in absorption refrigeration), carbon dioxide and non-halogenated hydrocarbons.

	It is important that the design of HVAC systems is considered as a part of the overall design process for the building, and not seen as an add on at the end. It is also important that HVAC systems are regularly maintained to ensure optimum performance and occupant comfort.		It is important that the design of HVAC systems is considered as a part of the overall design process for the building, and not seen as an add on at the end. It is also important that HVAC systems are regularly maintained to ensure optimum performance and occupant comfort.
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	=== Related articles on Designing Buildings Wiki ===		=== Related articles on Designing Buildings Wiki ===
−	*Absorption refrigeration.
−	*Air conditioning.
−	*Air handling unit.
−	*Chilled beam.
−	*Constant air volume.
−	*Fan coil unit.
−	*Heat pumps.
−	*Heat recovery.
−	*HVAC.
−	*Passive building design.
−	*Refrigerants.
−	*Thermal comfort.
−	*Variable air volume.
−	*Variable refrigerant flow.
−	*Ventilation.

−	[[Category:Articles_needing_more_work]]	+	* Absorption refrigeration.
−	[[Category:~~Products_/_components~~]] [[Category:DCN_Product_Knowledge]]	+	* Air conditioning.
		+	* Air handling unit.
		+	* Chilled beam.
		+	* Constant air volume.
		+	* Fan coil unit.
		+	* Heat pumps.
		+	* Heat recovery.
		+	* HVAC.
		+	* Passive building design.
		+	* Refrigerants.
		+	* Thermal comfort.
		+	* Variable air volume.
		+	* Variable refrigerant flow.
		+	* Ventilation.
		+
		+	[[Category:Articles_needing_more_work]] [[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:DCN_Product_Knowledge]] [[Category:Products_/_components]]

Designing Buildings at 13:21, 23 February 2015

2015-02-23T13:21:20Z

← Older revision		Revision as of 13:21, 23 February 2015
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	An alternative system supplies the refrigerant itself (rather than chilled water) to terminal units supplying different thermal zones. Variable refrigerant flow (VRF) systems use a single external condensing unit and multiple internal evaporators and can be more efficient, more compact and offer greater flexibility than other HVAC systems. See Variable refrigerant flow for more information.		An alternative system supplies the refrigerant itself (rather than chilled water) to terminal units supplying different thermal zones. Variable refrigerant flow (VRF) systems use a single external condensing unit and multiple internal evaporators and can be more efficient, more compact and offer greater flexibility than other HVAC systems. See Variable refrigerant flow for more information.

−	Some refrigerants have both ozone depletion potential (ODP) and global warming potential (GWP), and as a consequence refrigerants such as CFC’s (chlorofluorocarbons) are banned. New equipment using HCFCs ((hydrochlorofluorocarbons such as R22 and R408A) was banned in 2001 (2004 for small systems), and the use of virgin HCFC's was banned in 2010, when it also became illegal to manufacture HCFC refrigerants or for suppliers to keep them in stock. From January 1<sup>st</sup> 2015 the use of HCFC’s ~~will be~~ prohibited in any form, even for maintenance. The use of HFC's (hydrofluorocarbons, including 417A, 422A, 422D, 424A, 427A, 428A and 434A) continues to be permitted. Other refrigerants include, ammonia (common in absorption refrigeration), carbon dioxide and non-halogenated hydrocarbons.	+	Some refrigerants have both ozone depletion potential (ODP) and global warming potential (GWP), and as a consequence refrigerants such as CFC’s (chlorofluorocarbons) are banned. New equipment using HCFCs ((hydrochlorofluorocarbons such as R22 and R408A) was banned in 2001 (2004 for small systems), and the use of virgin HCFC's was banned in 2010, when it also became illegal to manufacture HCFC refrigerants or for suppliers to keep them in stock. From January 1<sup>st</sup> 2015 the use of HCFC’s was prohibited in any form, even for maintenance. The use of HFC's (hydrofluorocarbons, including 417A, 422A, 422D, 424A, 427A, 428A and 434A) continues to be permitted. Other refrigerants include, ammonia (common in absorption refrigeration), carbon dioxide and non-halogenated hydrocarbons.

	It is important that the design of HVAC systems is considered as a part of the overall design process for the building, and not seen as an add on at the end. It is also important that HVAC systems are regularly maintained to ensure optimum performance and occupant comfort.		It is important that the design of HVAC systems is considered as a part of the overall design process for the building, and not seen as an add on at the end. It is also important that HVAC systems are regularly maintained to ensure optimum performance and occupant comfort.
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	[[Category:Articles_needing_more_work]]		[[Category:Articles_needing_more_work]]
−	[[Category:Products_/_components]]	+	[[Category:Products_/_components]] [[Category:DCN_Product_Knowledge]]

Designing Buildings at 09:05, 23 October 2014

2014-10-23T09:05:59Z

← Older revision		Revision as of 09:05, 23 October 2014
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	=== Related articles on Designing Buildings Wiki ===		=== Related articles on Designing Buildings Wiki ===
		+	*Absorption refrigeration.
	*Air conditioning.		*Air conditioning.
	*Air handling unit.		*Air handling unit.

Designing Buildings at 08:05, 21 October 2014

2014-10-21T08:05:05Z

← Older revision		Revision as of 08:05, 21 October 2014
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	*HVAC.		*HVAC.
	*Passive building design.		*Passive building design.
		+	*Refrigerants.
	*Thermal comfort.		*Thermal comfort.
	*Variable air volume.		*Variable air volume.