Building insulation materials weak and brittle. Before its risks were recognized, it was used because it was a cheap, effective insulator with a high R-value and its open-cell structure was a good acoustic insulator. Though it absorbed moisture easily, it regained effectiveness as an insulator when dried. Asbestos once found common use as an insulation material in homes and buildings because it is fireproof, a good thermal and electrical insulator, and resistant to chemical attack and wear. It has been found that asbestos can cause cancer when in friable form (that is, when likely to release fibers into the air - when broken,
Building insulation by forming a radiation barrier by attaching metal foil on one side or both sides, this thermal insulation mainly reduces the radiation heat transfer. Although the polished metal foil attached on the materials can only prevent the radiation heat transfer, its effect to stop heat transfer can be dramatic. Another thermal insulation that doesn’t apply air cavity is vacuum insulation, the vacuum-insulated panels can stop all kinds of convection and conduction and it can also largely mitigate the radiation heat transfer. But the effectiveness of vacuum insulation is also limited by the edge of the material, since the edge of