Building insulation materials is used depends on a wide variety of factors. Some insulation materials have health risks, some so significant the materials are no longer allowed to be used but remain in use in some older buildings such as asbestos fibers and urea. Factors affecting the type and amount of insulation to use in a building include: Considerations regarding building and climate: Often a combination of materials is used to achieve an optimum solution and there are products which combine different types of insulation into a single form. Spray foam is a type of insulation that is sprayed in place through a
Building insulation of building heat transfer - conduction, convection, and radiation. According to three ways of heat exchange，most thermal insulation we used in our building can be divided into two categories: Conductive and convective insulators and radiant heat barriers. And there are more detailed classifications to distinguish between different materials. Many thermal insulation materials work by creating tiny air cavity between molecules, this air cavity can largely reduce the heat exchange through the materials. But there are two exceptions which don’t use air cavity as their functional element to prevent heat transfer. One is reflective thermal insulation, which creates a great airspace