Conductor - Revision history

Editor at 20:30, 17 February 2021

2021-02-17T20:30:42Z

← Older revision		Revision as of 20:30, 17 February 2021
Line 46:		Line 46:
	* Kilowatt hour.		* Kilowatt hour.
	* Latent heat.		* Latent heat.
		+	* Lightning conductor.
	* Mains electricity.		* Mains electricity.
	* Thermal mass.		* Thermal mass.

Designing Buildings at 07:11, 21 January 2021

2021-01-21T07:11:07Z

← Older revision		Revision as of 07:11, 21 January 2021
Line 51:		Line 51:
	* Urban heat island.		* Urban heat island.

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

Designing Buildings at 12:30, 11 August 2019

2019-08-11T12:30:45Z

← Older revision		Revision as of 12:30, 11 August 2019
Line 21:		Line 21:
	= Electrical conductance =		= Electrical conductance =

−	In electricity, a conductor is a material which offers low resistance to the flow of electricity (flow of electrons or electrically-charged particles) and is therefore able to conduct an electric current. Electrical conductivity (also known as ‘specific conductance’) is the rate at which a material conducts electricity. It is the reciprocal to electrical resistivity, the measure of how much a material resists the flow of an electrical current.	+	In relation to electricity, a conductor is a material which offers low resistance to the flow of electricity (the flow of electrons or electrically-charged particles) and is therefore able to conduct an electric current. Electrical conductivity (also known as ‘specific conductance’) is the rate at which a material conducts electricity. It is the reciprocal to electrical resistivity, the measure of how much a material resists the flow of an electrical current.

	Most metals and plasma have high electrical conductivity, but to different extents. Silver is regarded as the best electrical conductor; copper, gold, aluminium, zinc, nickel and brass follow. Copper is an excellent conductor and is used widely in wiring systems; aluminium is better than iron. Lead is a poor conductor compared to the aforementioned.		Most metals and plasma have high electrical conductivity, but to different extents. Silver is regarded as the best electrical conductor; copper, gold, aluminium, zinc, nickel and brass follow. Copper is an excellent conductor and is used widely in wiring systems; aluminium is better than iron. Lead is a poor conductor compared to the aforementioned.

−	Electrical conductivity occurs in various degrees in these metals due to the ease with which electrons in the outer shell of an atom (valence or free electrons) can be separated and are free to travel around, ~~knocking into each other and~~ passing on an electric charge. Temperature also plays a part: when the temperature of metallic conductors is decreased, the electrical conductivity increases.	+	Electrical conductivity occurs in various degrees in these metals due to the ease with which electrons in the outer shell of an atom (valence or free electrons) can be separated and are free to travel around, passing on an electric charge. Temperature also plays a part: when the temperature of metallic conductors is decreased, the electrical conductivity increases.

	Other materials such as dry wood, glass, paper, rubber, diamond, air and most plastics are poor electrical conductors and are therefore said to be non-conductors or insulators.		Other materials such as dry wood, glass, paper, rubber, diamond, air and most plastics are poor electrical conductors and are therefore said to be non-conductors or insulators.

−	Semi-conductors such as silicon and germanium can also conduct electricity but are not particularly efficient at doing so. They must therefore be heated or ‘doped’ with other elements, after which they become extremely efficient electrical conductors.	+	Semi-conductors such as silicon and germanium can also conduct electricity but are not particularly efficient at doing so. They must therefore be heated or ‘doped’ with other elements, after which they can become extremely efficient electrical conductors.

	= Related articles on Designing Buildings Wiki =		= Related articles on Designing Buildings Wiki =
Line 36:		Line 36:
	* Ampere.		* Ampere.
	* Articles about electricity.		* Articles about electricity.
		+	* Cold bridge.
	* Conduction.		* Conduction.
	* Consumer electronics.		* Consumer electronics.
−	* Convection.
	* Electrical energy.		* Electrical energy.
	* Electrical power.		* Electrical power.
	* Energy consumption.		* Energy consumption.
	* Glossary of electrical terms.		* Glossary of electrical terms.
−	* Heat meter.
−	* Heat stress.
	* Heat transfer.		* Heat transfer.
	* Kilowatt hour.		* Kilowatt hour.
	* Latent heat.		* Latent heat.
	* Mains electricity.		* Mains electricity.
−	* Radiant heating.
−	* Radiation.
−	* Solar gain.
−	* Specific heat capacity.
−	* The future of electricity in domestic buildings.
	* Thermal mass.		* Thermal mass.
	* U value.		* U value.
	* Urban heat island.		* Urban heat island.

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

Designing Buildings at 12:27, 11 August 2019

2019-08-11T12:27:56Z

← Older revision		Revision as of 12:27, 11 August 2019
Line 3:		Line 3:
	A conductor is a material that conducts heat or electricity – or both.		A conductor is a material that conducts heat or electricity – or both.

−	Conduction is the process whereby heat or electricity move ~~within~~ a material.	+	Conduction is the process whereby heat or electricity diffuses, or move across a material as a result of a difference between its parts. Conductivity is the rate at which conduction occurs.
−		+
−	Conductivity is the rate at which conduction occurs.	+

	= Thermal conductance =		= Thermal conductance =

−	A conductor is a material with a high thermal conductivity, i.e. it allows heat to pass freely through it when there is a temperature difference between it and the ambient environment or between it and another ~~material~~ with which it is in contact.	+	A conductor is a material with a high thermal conductivity, i.e. it allows heat to pass freely through it when there is a temperature difference between it and the ambient environment or between it and another substance with which it is in contact.
−		+
−	~~Materials with high thermal conductivity tend to be poor insulators (e.g metals) as opposed to materials with low thermal conductivities that tend to be good insulators (e.g PVC)~~.	+

−	~~In building construction, a material~~ with ~~a low~~ thermal conductivity ~~and hence a good insulator can be used~~ to ~~increase the thermal performance of wall and roof constructions. Polystyrene, polyurethane and mineral fibre are all excellent~~ insulators ~~that provide good resistance to the passage of heat~~. ~~They are therefore used~~ to ~~help constructions attain the~~ thermal ~~performance~~ (~~U-values~~) ~~required by building regulations~~.	+	Materials with high thermal conductivity tend to be poor insulators (e.g metals) as opposed to materials with low thermal conductivities that tend to be good insulators (e.g polystyrene).

−	~~All materials conduct heat~~ to ~~a greater or lesser extent. If this were not~~ the ~~case, situations~~ such as ~~cold bridging would not be possible~~. ~~Cold bridging occurs when~~ heat ~~inside a building finds a pathway~~ to ~~the outside~~ (~~which is colder~~) ~~through~~ the ~~layers of construction~~ (~~and the air spaces~~) ~~that are in contact with each other~~. ~~This passage of heat would be reversed if the inside of the building was at a lower temperature than the outside~~.	+	In building construction, a material with a low thermal conductivity and hence a good insulator can be used to improve the thermal performance building elements such as wall and roof constructions. Polystyrene, polyurethane and mineral fibre are all excellent insulators that provide good resistance to the passage of heat. They are therefore used to help constructions attain (or exceed) the thermal performance (U-values) required by building regulations. For more information see: Insulation.

−	In a ~~typical cold bridge scenario in a cold climate~~, heat ~~is conducted toward~~ the outside through the ~~various~~ layers of construction~~, forming a path of heat loss~~ and ~~possible condensation~~. This occurs because even poor heat conductors such as concrete and masonry will allow some heat to pass through when there is a temperature difference ~~between~~ them. Preventing cold bridging requires breaking this path of heat transfer using a material of low thermal conductivity, i.e. an insulator such as polystyrene, but it also means ensuring there are no air spaces on critical paths.	+	All materials conduct heat to a greater or lesser extent. If this were not the case, situations such as cold bridging would not occur. Cold bridging occurs when heat inside a building finds a pathway to the outside (when it is colder) through the layers of construction (and the air spaces) that are in contact with each other. This occurs because even poor heat conductors such as concrete and masonry will allow some heat to pass through when there is a temperature difference across them. Preventing cold bridging requires breaking this path of heat transfer using a material of low thermal conductivity, i.e. an insulator such as polystyrene, but it also means ensuring there are no air spaces on critical paths. For more information see: Cold bridge.

−	~~Air~~ is a ~~relatively good conductor~~ of ~~heat and when there are gaps~~ in ~~say, cavity insulation, heat may be conducted to~~ the ~~outside through~~ air ~~pockets~~. ~~Cold bridging may occur where cavity insulation does not extend to below DPC level as may often happen~~.	+	The internal to external thermal transmittance rate of a construction assembly is known as a U-value (i.e. the number of Watts transmitted through 1m2 of construction per degree Kelvin difference in temperature between the air on each side of the construction). For more information see: U Value.

−	The internal to external thermal transmittance rate of a construction assembly is known as a U-value (i.e. the number of Watts transmitted through 1m2 of construction per degree Kelvin difference in temperature between the air on each side of the construction. U-values tend to be not entirely accurate as heat flow through a construction can depend on the amount of solar absorption, the effects of prevailing winds and moisture conditions.	+	See also Thermal conduction.

	= Electrical conductance =		= Electrical conductance =

Editor: Created page with "= Conductor = A conductor is a material that conducts heat or electricity – or both. Conduction is the process whereby heat or electricity move within a material. Conductivi..."

2019-08-03T15:04:10Z

Created page with "= Conductor = A conductor is a material that conducts heat or electricity – or both. Conduction is the process whereby heat or electricity move within a material. Conductivi..."

New page

= Conductor =

A conductor is a material that conducts heat or electricity – or both.

Conduction is the process whereby heat or electricity move within a material.

Conductivity is the rate at which conduction occurs.

= Thermal conductance =

A conductor is a material with a high thermal conductivity, i.e. it allows heat to pass freely through it when there is a temperature difference between it and the ambient environment or between it and another material with which it is in contact.

Materials with high thermal conductivity tend to be poor insulators (e.g metals) as opposed to materials with low thermal conductivities that tend to be good insulators (e.g PVC).

In building construction, a material with a low thermal conductivity and hence a good insulator can be used to increase the thermal performance of wall and roof constructions. Polystyrene, polyurethane and mineral fibre are all excellent insulators that provide good resistance to the passage of heat. They are therefore used to help constructions attain the thermal performance (U-values) required by building regulations.

All materials conduct heat to a greater or lesser extent. If this were not the case, situations such as cold bridging would not be possible. Cold bridging occurs when heat inside a building finds a pathway to the outside (which is colder) through the layers of construction (and the air spaces) that are in contact with each other. This passage of heat would be reversed if the inside of the building was at a lower temperature than the outside.

In a typical cold bridge scenario in a cold climate, heat is conducted toward the outside through the various layers of construction, forming a path of heat loss and possible condensation. This occurs because even poor heat conductors such as concrete and masonry will allow some heat to pass through when there is a temperature difference between them. Preventing cold bridging requires breaking this path of heat transfer using a material of low thermal conductivity, i.e. an insulator such as polystyrene, but it also means ensuring there are no air spaces on critical paths.

Air is a relatively good conductor of heat and when there are gaps in say, cavity insulation, heat may be conducted to the outside through air pockets. Cold bridging may occur where cavity insulation does not extend to below DPC level as may often happen.

The internal to external thermal transmittance rate of a construction assembly is known as a U-value (i.e. the number of Watts transmitted through 1m2 of construction per degree Kelvin difference in temperature between the air on each side of the construction. U-values tend to be not entirely accurate as heat flow through a construction can depend on the amount of solar absorption, the effects of prevailing winds and moisture conditions.

= Electrical conductance =

In electricity, a conductor is a material which offers low resistance to the flow of electricity (flow of electrons or electrically-charged particles) and is therefore able to conduct an electric current. Electrical conductivity (also known as ‘specific conductance’) is the rate at which a material conducts electricity. It is the reciprocal to electrical resistivity, the measure of how much a material resists the flow of an electrical current.

Most metals and plasma have high electrical conductivity, but to different extents. Silver is regarded as the best electrical conductor; copper, gold, aluminium, zinc, nickel and brass follow. Copper is an excellent conductor and is used widely in wiring systems; aluminium is better than iron. Lead is a poor conductor compared to the aforementioned.

Electrical conductivity occurs in various degrees in these metals due to the ease with which electrons in the outer shell of an atom (valence or free electrons) can be separated and are free to travel around, knocking into each other and passing on an electric charge. Temperature also plays a part: when the temperature of metallic conductors is decreased, the electrical conductivity increases.

Other materials such as dry wood, glass, paper, rubber, diamond, air and most plastics are poor electrical conductors and are therefore said to be non-conductors or insulators.

Semi-conductors such as silicon and germanium can also conduct electricity but are not particularly efficient at doing so. They must therefore be heated or ‘doped’ with other elements, after which they become extremely efficient electrical conductors.

= Related articles on Designing Buildings Wiki =

* Alternating current and direct current.
* Ampere.
* Articles about electricity.
* Conduction.
* Consumer electronics.
* Convection.
* Electrical energy.
* Electrical power.
* Energy consumption.
* Glossary of electrical terms.
* Heat meter.
* Heat stress.
* Heat transfer.
* Kilowatt hour.
* Latent heat.
* Mains electricity.
* Radiant heating.
* Radiation.
* Solar gain.
* Specific heat capacity.
* The future of electricity in domestic buildings.
* Thermal mass.
* U value.
* Urban heat island.

[[Category:Theory]] [[Category:Products_/_components]]