Dewing in the building is a problem paid more and more attention by people as the development of living
standards. If the temperature of the surface of wall is lower than the dew point temperature of the air nearby, it will
dew in the surface. Dew may change the appearance and the shape of the ornamental and even exfoliate it. At the
same time, liquid water will move to the inner part of the wall, which may destroy the construction and the metal
parts in it, or even germs may breed to make secondly disaster.