This study used desiccants of silica gel and sodium polyacrylate coated on fin and tube heat exchangers to enhance the absorption of water vapor in the air. The experimental results show that, while the temperature and relative humidity of the inlet air are 25°C and 85% RH, respectively, the vapor absorbent capacities of the two desiccants are better than that with the conventional method under different inlet air temperatures. The enhanced dehumidification efficiencies of sodium polyacrylate and silica gel are 64% and 42.8%, respectively, as compared to that of the conventional cooling and dehumidification method. The two desiccant coating heat exchangers are also operated periodically in mass equilibrium states between the absorption and regeneration processes. While hot water of 60°C was supplied for the regeneration process, after reaching an equilibrium state in periodic cycles, the average vapor absorption rates per unite desiccant are 0.0018g<inf>vapor</inf>(g min) for silica gel and 0.004g<inf>vapor</inf>/(g min) for sodium polyacrylate. For the desiccant of sodium polyacrylate, the period of absorption process could be much longer, and the vapor could be discharged in a shorter period in the regeneration process. Thus, the dehumidification efficiency of sodium polyacrylate in DCHE has much better performance than that of silica gel. (10 refs)
