Thermal conduction in buildings - Revision history

Designing Buildings at 05:48, 7 October 2020

2020-10-07T05:48:52Z

← Older revision		Revision as of 05:48, 7 October 2020
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	* U value.		* U value.

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

Editor at 18:09, 2 September 2019

2019-09-02T18:09:36Z

← Older revision		Revision as of 18:09, 2 September 2019
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	This time lag can be exploited by introducing thermal mass into the fabric of a building. Thermal mass describes the ability of a material to absorb, store and release heat energy. Thermal mass can be used to even out variations in internal and external conditions, absorbing heat as temperatures rise and releasing it as they fall. This can useful for evening-out and delaying extremes in thermal conditions, stabilising the internal environment and so reducing the demand for building services systems. See Thermal mass for more information.		This time lag can be exploited by introducing thermal mass into the fabric of a building. Thermal mass describes the ability of a material to absorb, store and release heat energy. Thermal mass can be used to even out variations in internal and external conditions, absorbing heat as temperatures rise and releasing it as they fall. This can useful for evening-out and delaying extremes in thermal conditions, stabilising the internal environment and so reducing the demand for building services systems. See Thermal mass for more information.

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

	* Building fabric.		* Building fabric.
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	* Thermal bridge.		* Thermal bridge.
	* Thermal optical properties.		* Thermal optical properties.
		+	* Thermal performance
	* Thermal mass.		* Thermal mass.
	* U value.		* U value.

	[[Category:Sustainability]] [[Category:Design]]		[[Category:Sustainability]] [[Category:Design]]

Editor at 11:57, 27 June 2017

2017-06-27T11:57:05Z

← Older revision		Revision as of 11:57, 27 June 2017
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	* Building services.		* Building services.
	* Convection.		* Convection.
		+	* Double glazing.
	* Emissivity.		* Emissivity.
	* Heat transfer		* Heat transfer

Editor at 12:33, 1 June 2017

2017-06-01T12:33:23Z

← Older revision		Revision as of 12:33, 1 June 2017
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	* Natural ventilation.		* Natural ventilation.
	* Passive building design.		* Passive building design.
		+	* Radiator.
	* Solar gain.		* Solar gain.
	* Solar radiation.		* Solar radiation.

Designing Buildings: Reverted edits by 209.81.124.34 (talk) to last revision by Editor

2017-03-27T15:35:06Z

Reverted edits by 209.81.124.34 (talk) to last revision by Editor

← Older revision		Revision as of 15:35, 27 March 2017
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	It is sometimes thought that conductivity is described by the U-Value, however, U-values include inside and outside surface thermal resistances. Conductivity is more accurately expressed by a material's R-Value, which is the reciprocal of its thermal resistance and does not include a surface component. See U-Value for more information.		It is sometimes thought that conductivity is described by the U-Value, however, U-values include inside and outside surface thermal resistances. Conductivity is more accurately expressed by a material's R-Value, which is the reciprocal of its thermal resistance and does not include a surface component. See U-Value for more information.

−	Conductive heat transfer is particularly high across narrow, highly conductive components such as windows. It can be inhibited by insulating materials which have a high thermal resistance. See insulation for more information. Typically conductive heat transfer is reduced by creating breaks in the continuity of a material, such as the air (or other gas) in insulation, or the air or gas filled space between the panes of glass in double or triple glazing. This breaks the conductive flow, replacing it with surface resistances and a convective heat transfer across gap. ~~snap me - jackpenney7620~~	+	Conductive heat transfer is particularly high across narrow, highly conductive components such as windows. It can be inhibited by insulating materials which have a high thermal resistance. See insulation for more information. Typically conductive heat transfer is reduced by creating breaks in the continuity of a material, such as the air (or other gas) in insulation, or the air or gas filled space between the panes of glass in double or triple glazing. This breaks the conductive flow, replacing it with surface resistances and a convective heat transfer across gap.

	A thermal bridge describes a situation where there is a direct connection between the inside and outside through one or more elements that are more thermally conductive than the rest of the building envelope. As a result, there will be wasteful heat transfer across that element, its internal surface temperature will be different from other, better insulated areas and there may be condensation where warm, moist internal air comes into contact with the, potentially cold, surface. This condensation can result in mould growth. See Thermal bridge for more information.		A thermal bridge describes a situation where there is a direct connection between the inside and outside through one or more elements that are more thermally conductive than the rest of the building envelope. As a result, there will be wasteful heat transfer across that element, its internal surface temperature will be different from other, better insulated areas and there may be condensation where warm, moist internal air comes into contact with the, potentially cold, surface. This condensation can result in mould growth. See Thermal bridge for more information.
Line 48:		Line 48:
	* U value.		* U value.

−	~~[[Category:Articles_needing_more_work]]~~ [[Category:Sustainability]] [[Category:Design]]	+	[[Category:Sustainability]] [[Category:Design]]

209.81.124.34 at 15:08, 27 March 2017

2017-03-27T15:08:41Z

← Older revision		Revision as of 15:08, 27 March 2017
Line 20:		Line 20:
	It is sometimes thought that conductivity is described by the U-Value, however, U-values include inside and outside surface thermal resistances. Conductivity is more accurately expressed by a material's R-Value, which is the reciprocal of its thermal resistance and does not include a surface component. See U-Value for more information.		It is sometimes thought that conductivity is described by the U-Value, however, U-values include inside and outside surface thermal resistances. Conductivity is more accurately expressed by a material's R-Value, which is the reciprocal of its thermal resistance and does not include a surface component. See U-Value for more information.

−	Conductive heat transfer is particularly high across narrow, highly conductive components such as windows. It can be inhibited by insulating materials which have a high thermal resistance. See insulation for more information. Typically conductive heat transfer is reduced by creating breaks in the continuity of a material, such as the air (or other gas) in insulation, or the air or gas filled space between the panes of glass in double or triple glazing. This breaks the conductive flow, replacing it with surface resistances and a convective heat transfer across gap.	+	Conductive heat transfer is particularly high across narrow, highly conductive components such as windows. It can be inhibited by insulating materials which have a high thermal resistance. See insulation for more information. Typically conductive heat transfer is reduced by creating breaks in the continuity of a material, such as the air (or other gas) in insulation, or the air or gas filled space between the panes of glass in double or triple glazing. This breaks the conductive flow, replacing it with surface resistances and a convective heat transfer across gap. snap me - jackpenney7620

	A thermal bridge describes a situation where there is a direct connection between the inside and outside through one or more elements that are more thermally conductive than the rest of the building envelope. As a result, there will be wasteful heat transfer across that element, its internal surface temperature will be different from other, better insulated areas and there may be condensation where warm, moist internal air comes into contact with the, potentially cold, surface. This condensation can result in mould growth. See Thermal bridge for more information.		A thermal bridge describes a situation where there is a direct connection between the inside and outside through one or more elements that are more thermally conductive than the rest of the building envelope. As a result, there will be wasteful heat transfer across that element, its internal surface temperature will be different from other, better insulated areas and there may be condensation where warm, moist internal air comes into contact with the, potentially cold, surface. This condensation can result in mould growth. See Thermal bridge for more information.
Line 48:		Line 48:
	* U value.		* U value.

−	[[Category:Sustainability]] [[Category:Design]]	+	[[Category:Articles_needing_more_work]] [[Category:Sustainability]] [[Category:Design]]

Editor at 14:31, 12 July 2016

2016-07-12T14:31:40Z

← Older revision		Revision as of 14:31, 12 July 2016
Line 1:		Line 1:
−
	Thermal conduction is the diffusion of internal heat within a static (rather than fluid) body as a result of a temperature difference across it. Heat will tend to diffuse from higher temperature parts of a body to lower temperature parts.		Thermal conduction is the diffusion of internal heat within a static (rather than fluid) body as a result of a temperature difference across it. Heat will tend to diffuse from higher temperature parts of a body to lower temperature parts.

−	This is particularly important in buildings where there may be a temperature difference between the inside and outside, for example, in a heated building during the winter, or in a cooled building during the summer.	+	This is particularly important in buildings where there may be a temperature difference between the inside and outside, for example, in a heated building during the winter, or in a cooled building during the summer.

	Conduction is one of the main potential heat transfer mechanisms by which the internal heating or cooling can be lost to the outside, resulting in high operating costs, high carbon emissions and occupant discomfort.		Conduction is one of the main potential heat transfer mechanisms by which the internal heating or cooling can be lost to the outside, resulting in high operating costs, high carbon emissions and occupant discomfort.
Line 11:		Line 10:

	Where:		Where:
−	*A is the area of the body (m2)	+
−	*k is the ~~body’s~~ thermal conductivity (W/m°C)	+	* A is the area of the body (m2)
−	*dT is the temperature difference across the body (°C)	+	* k is the body's thermal conductivity (W/m°C)
−	*s is the ~~body’s~~ thickness (m)	+	* dT is the temperature difference across the body (°C)
		+	* s is the body's thickness (m)

	To determine the heat transfer between the inside and outside of a building component, it may be necessary to calculate the conductive heat transfer across a number of layers, and the internal and external surface resistances. This is sometimes calculated using a U-Value. In simple terms, the lower the U-value of an element of a building's fabric, the less heat will transmit across it. U-values are expressed in watts per square metre per degree Kelvin (W/m2K).		To determine the heat transfer between the inside and outside of a building component, it may be necessary to calculate the conductive heat transfer across a number of layers, and the internal and external surface resistances. This is sometimes calculated using a U-Value. In simple terms, the lower the U-value of an element of a building's fabric, the less heat will transmit across it. U-values are expressed in watts per square metre per degree Kelvin (W/m2K).
Line 31:		Line 31:

	=== Related articles on Designing Buildings Wiki ===		=== Related articles on Designing Buildings Wiki ===
−	*Building services.
−	*Convection.
−	*Emissivity.
−	*Heat transfer
−	*Insulation.
−	*Long wave infra red radiation.
−	*Natural ventilation.
−	*Passive building design.
−	*Solar gain.
−	*Solar radiation.
−	*Thermal bridge.
−	*Thermal optical properties.
−	*Thermal mass.
−	*U value.

−	[[Category:Sustainability]]	+	* Building fabric.
−	[[Category:Design]]	+	* Building services.
		+	* Convection.
		+	* Emissivity.
		+	* Heat transfer
		+	* Insulation.
		+	* Long wave infra red radiation.
		+	* Natural ventilation.
		+	* Passive building design.
		+	* Solar gain.
		+	* Solar radiation.
		+	* Thermal bridge.
		+	* Thermal optical properties.
		+	* Thermal mass.
		+	* U value.
		+
		+	[[Category:Sustainability]] [[Category:Design]]

Designing Buildings: moved Conduction to Thermal conduction in buildings

2014-10-25T08:22:03Z

moved Conduction to Thermal conduction in buildings

← Older revision

Revision as of 08:22, 25 October 2014

Designing Buildings at 08:19, 25 October 2014

2014-10-25T08:19:10Z

Designing Buildings: Created page with " Thermal conduction is the diffusion of internal heat within a static (rather than fluid) body as a result of a temperature difference across it. Heat will tend to diffuse from ..."

2014-10-25T08:13:23Z

Created page with " Thermal conduction is the diffusion of internal heat within a static (rather than fluid) body as a result of a temperature difference across it. Heat will tend to diffuse from ..."

New page

Thermal conduction is the diffusion of internal heat within a static (rather than fluid) body as a result of a temperature difference across it. Heat will tend to diffuse from higher temperature parts of a body to lower temperature parts.

This is particularly important in buildings where there may be a temperature difference between the inside and outside of a building, for example, in a heated building during the winter, or in a cooled building during the summer. Conduction is one of the main potential heat transfer mechanisms by which the internal heating or cooling can be lost to the outside, resulting in high operating costs, high carbon emissions and occupant discomfort.

Simple conductive heat transfer (in watts) through a uniform body can be calculated from Fourier's Law:

q = k A dT / s

Where:
*A is the area of the body (m2)
*k is the body’s thermal conductivity (W/m°C)
*dT is the temperature difference across the body (°C)
*s is the body’s thickness (m, ft)

To determine the heat transfer between the inside and outside of a building component, it may be necessary to calculate the conductive heat transfer across a number of layers, and the surface resistances. This is sometimes calculated using its U-Value. In simple terms, the lower the U-value of an element of a building's fabric, the less heat will transmit across it. U-values are expressed in watts per square metre per degree Kelvin (W/m2K).

It is sometimes thought that conductivity is expressed by the U-Value, however, U-values are the reciprocal of the sum of the thermal resistances of a body plus its inside and outside surface thermal resistances. Conductivity is more accurately expressed by a material's R-Value, which is the reciprocal of its thermal resistance and does not include a surface component. See U-Value for more information.

Conductive heat transfer is particularly high across narrow, highly conductive components such as windows. It can be inhibited by insulating materials which have a high thermal resistance. See insulation for more information. Typically conductive heat transfer is reduced by creating breaks in the continuity of a material, such as the air (or other gas) in insulation, or the air or gas filled space between the panes of glass in double or triple glazing. This breaks the conductive flow, replacing it with a surface resistance and convective heat transfer between the surfaces on either side of the gap.

A thermal bridge describes a situation where there is a direct connection between the inside and outside through one or more elements that are more thermally conductive than the rest of the building envelope. As a result, there will be wasteful heat transfer across that element, its internal surface temperature will be different from other, better insulated internal surfaces and there may be condensation where warm, moist internal air comes into contact with the, potentially cold, surface. This condensation can result in mould growth. See Thermal bridge for more information.

In practice, temperatures do not remain constant (steady state) and the transfer of heat across a body is not instantaneous. Dynamic analysis of conductive heat transfer considers the changing temperature profiles on either side of a body and the time lag introduced by the rate of diffusion of heat through the body.

This time lag can be exploited by introducing thermal mass into the fabric of a building. Thermal mass describes the ability of a material to absorb, store and release heat energy. Thermal mass can be used to even out variations in internal and external conditions, absorbing heat as temperatures rise and releasing it as they fall. This can useful for evening-out and delaying extremes in thermal conditions, stabilising the internal environment and so reducing the demand for building services systems. See Thermal mass for more information.

= Find out more =

=== Related articles on Designing Buildings Wiki ===
*Building services.
*Convection.
*Emissivity.
*Heat transfer
*Insulation.
*Long wave infra red radiation.
*Natural ventilation.
*Passive building design.
*Solar gain.
*Solar radiation.
*Thermal bridge.
*Thermal optical properties.
*Thermal mass.
*U value.

[[Category:Sustainability]]
[[Category:Design]]

← Older revision		Revision as of 08:19, 25 October 2014
Line 1:		Line 1:
−

	Thermal conduction is the diffusion of internal heat within a static (rather than fluid) body as a result of a temperature difference across it. Heat will tend to diffuse from higher temperature parts of a body to lower temperature parts.		Thermal conduction is the diffusion of internal heat within a static (rather than fluid) body as a result of a temperature difference across it. Heat will tend to diffuse from higher temperature parts of a body to lower temperature parts.

−	This is particularly important in buildings where there may be a temperature difference between the inside and outside ~~of a building~~, for example, in a heated building during the winter, or in a cooled building during the summer. Conduction is one of the main potential heat transfer mechanisms by which the internal heating or cooling can be lost to the outside, resulting in high operating costs, high carbon emissions and occupant discomfort.	+	This is particularly important in buildings where there may be a temperature difference between the inside and outside, for example, in a heated building during the winter, or in a cooled building during the summer.
		+
		+	Conduction is one of the main potential heat transfer mechanisms by which the internal heating or cooling can be lost to the outside, resulting in high operating costs, high carbon emissions and occupant discomfort.

	Simple conductive heat transfer (in watts) through a uniform body can be calculated from Fourier's Law:		Simple conductive heat transfer (in watts) through a uniform body can be calculated from Fourier's Law:
Line 13:		Line 14:
	*k is the body’s thermal conductivity (W/m°C)		*k is the body’s thermal conductivity (W/m°C)
	*dT is the temperature difference across the body (°C)		*dT is the temperature difference across the body (°C)
−	*s is the body’s thickness (m~~, ft~~)	+	*s is the body’s thickness (m)

−	To determine the heat transfer between the inside and outside of a building component, it may be necessary to calculate the conductive heat transfer across a number of layers, and the surface resistances. This is sometimes calculated using ~~its~~ U-Value. In simple terms, the lower the U-value of an element of a building's fabric, the less heat will transmit across it. U-values are expressed in watts per square metre per degree Kelvin (W/m2K).	+	To determine the heat transfer between the inside and outside of a building component, it may be necessary to calculate the conductive heat transfer across a number of layers, and the internal and external surface resistances. This is sometimes calculated using a U-Value. In simple terms, the lower the U-value of an element of a building's fabric, the less heat will transmit across it. U-values are expressed in watts per square metre per degree Kelvin (W/m2K).

−	It is sometimes thought that conductivity is ~~expressed~~ by the U-Value, however, U-values ~~are the reciprocal of the sum of the thermal resistances of a body plus its~~ inside and outside surface thermal resistances. Conductivity is more accurately expressed by a material's R-Value, which is the reciprocal of its thermal resistance and does not include a surface component. See U-Value for more information.	+	It is sometimes thought that conductivity is described by the U-Value, however, U-values include inside and outside surface thermal resistances. Conductivity is more accurately expressed by a material's R-Value, which is the reciprocal of its thermal resistance and does not include a surface component. See U-Value for more information.

−	Conductive heat transfer is particularly high across narrow, highly conductive components such as windows. It can be inhibited by insulating materials which have a high thermal resistance. See insulation for more information. Typically conductive heat transfer is reduced by creating breaks in the continuity of a material, such as the air (or other gas) in insulation, or the air or gas filled space between the panes of glass in double or triple glazing. This breaks the conductive flow, replacing it with a surface ~~resistance~~ and convective heat transfer ~~between the surfaces on either side of the~~ gap.	+	Conductive heat transfer is particularly high across narrow, highly conductive components such as windows. It can be inhibited by insulating materials which have a high thermal resistance. See insulation for more information. Typically conductive heat transfer is reduced by creating breaks in the continuity of a material, such as the air (or other gas) in insulation, or the air or gas filled space between the panes of glass in double or triple glazing. This breaks the conductive flow, replacing it with surface resistances and a convective heat transfer across gap.

−	A thermal bridge describes a situation where there is a direct connection between the inside and outside through one or more elements that are more thermally conductive than the rest of the building envelope. As a result, there will be wasteful heat transfer across that element, its internal surface temperature will be different from other, better insulated ~~internal surfaces~~ and there may be condensation where warm, moist internal air comes into contact with the, potentially cold, surface. This condensation can result in mould growth. See Thermal bridge for more information.	+	A thermal bridge describes a situation where there is a direct connection between the inside and outside through one or more elements that are more thermally conductive than the rest of the building envelope. As a result, there will be wasteful heat transfer across that element, its internal surface temperature will be different from other, better insulated areas and there may be condensation where warm, moist internal air comes into contact with the, potentially cold, surface. This condensation can result in mould growth. See Thermal bridge for more information.

−	In practice, temperatures do not remain constant (steady state) and the transfer of heat across a body is not instantaneous. Dynamic analysis of conductive heat transfer considers the changing temperature profiles on either side of a body and the time lag introduced by the rate of diffusion of heat through the body.	+	In practice, inside and outside temperatures do not remain constant (steady state) and the transfer of heat across a body is not instantaneous. Dynamic analysis of conductive heat transfer considers the changing temperature profiles on either side of a body and the time lag introduced by the rate of diffusion of heat through the body.

	This time lag can be exploited by introducing thermal mass into the fabric of a building. Thermal mass describes the ability of a material to absorb, store and release heat energy. Thermal mass can be used to even out variations in internal and external conditions, absorbing heat as temperatures rise and releasing it as they fall. This can useful for evening-out and delaying extremes in thermal conditions, stabilising the internal environment and so reducing the demand for building services systems. See Thermal mass for more information.		This time lag can be exploited by introducing thermal mass into the fabric of a building. Thermal mass describes the ability of a material to absorb, store and release heat energy. Thermal mass can be used to even out variations in internal and external conditions, absorbing heat as temperatures rise and releasing it as they fall. This can useful for evening-out and delaying extremes in thermal conditions, stabilising the internal environment and so reducing the demand for building services systems. See Thermal mass for more information.