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 which lead to a thinner thickness of thermal insulation to the building shell compared with traditional materials. The VIPs are usually composed of core panels and metallic enclosures. The common materials that used to produce Core panels are fumed and precipitated silica, open-cell polyurethane (PU), and different types of fiberglass. And the core panel is covered by the metallic enclosure to create a vacuum environment, the metallic enclosure can make sure that the core panel is kept in the vacuum environment. Although this material has a high thermal performance, it still maintains a high price in the last twenty years.