|
( Thermal insulation)
The term thermal insulation can refer to materials used to reduce the rate of heat transfer, or the methods and processes used to reduce heat transfer. The flow of heat can be delayed by addressing one or more of these mechanisms and is dependent on the physical properties of the material employed to do this. Thermal radiant barriers possess the characteristics of low emissivity, low absorptivity and high reflectivity in the infra-red spectrum. They may also exhibit this for other wavelengths including visible light but this is not necessary to function as thermal barrier. Only a small fraction of radiant energy is absorbed by such a material (most being reflected back away) and therefore only a small fraction is re-emitted. Highly polished metals are one example. Conversely, dark materials with low reflectivity will absorb a large fraction of energy, and similarly emit a large fraction. (see Black Body, Grey Body) Conduction occurs when heat travels through a medium. The rate at which this occurs is proportional to the thickness of the material, the cross-sectional area over which it travels, the temperature gradients between its surfaces and its thermal conductivity.
|
Thermal insulation Subcategories
Thermal insulation Articles
|
| 
