In this paper, there are some physical and mathematics models established about preventing frostdeposit on wet air side of heat exchanger. The effectiveness has been proved both theoretically and practically to prevent the frostdeposit in a wet air side of heat exchanger covered with high hydrophobic film. The study results would been shown in two aspects. First, the frost is formed on the surface itself, that is the phenomena in the initial stage of frost formation. Second, dust particles from the air stream can form ice crystals, and the crystals deposit on the surface.
