Insulation
The term "thermal insulation" refers to a material or combination of materials that slows the transfer of heat from high temperature (hot) regions to low temperature (cold) regions. Thermal insulation is placed between regions or surfaces having different temperatures to reduce heat flux—heat flow rate per unit area. In general, the heat flow increases as the temperature difference increases. The heat flux also depends on the type of material between the hot and cold surfaces. If the material between the surfaces is a thermal insulation—a material with relatively low values of a property called apparent thermal conductivity—then the heat flux will be small. As an added bonus, most building thermal insulation also function as effective sound or acoustical insulation.
The development of better thermal insulation is important since space heating and cooling account for the majority of energy consumption in the residential sector, and are second only to lighting in the commercial sector. Because of advances in insulation and more efficient heating systems, the U.S. Department of Energy projects that the energy used for space heating will drop at least 25 percent per household by 2020 relative to 1997 usage.
Historical Development
The use of thermal insulation dates back to ancient times, when primitive man used animal skins for clothing and built structures for protection from the elements.
This page contains 201 words.
Insulation article
Read the rest of this article.
This article contains 2,867 words
(approx. 10 pages at 300 words per page).
Order our Insulation Article
