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 materials cannot satisfy people’s long-term need for thermal insulation.so, people began to search for substitutes which are more durable. In the 19th century, people are no longer satisfied with using natural materials for thermal insulation, they processed the organic materials and produced the first insulated panels. At the same time, more and more artificial materials start to emerge, a large range of artificial thermal insulation materials were developed, rock wool, fiberglass, foam glass, hollow bricks. Thermal insulation can be a significant role in the building, great demands of thermal comfort result in a large amount of energy consumed for full-heating