Prevention of dew condensation on the case surfaces of ceiling-cassette indoor air conditioning units

We proposed a new method for preventing dew condensation on the case surfaces of ceiling-cassette indoor air conditioning units. We investigated the dew condensation problem numerically using a diffusion boundary layer phase-change model that incorporates the effect of non-condensable gases. By installing a blocking device on the case surface, we significantly reduced the suction flow of warm, humid air and the total condensation rate on the surface. We optimized the installation location, height, and angle of the blockage in order to minimize dew condensation. When the optimized blockage device was installed, and the air conditioning unit was operated at low discharge speed, we observed that the total numerical and experimental condensation rate fell by 41 and 30%, respectively.