Water Mass Flow and Air Relative Humidity on Performance of Air - Source Heat Pump Water Heater

The water mass flow and air relative humidity on the performance of air-source heat pump water heater was discussed in this paper. The results show that the energy efficiency of heat pump water heater is improved by correct the water mass flow and discharge pressure can be reduced, the value of the condenser temperature difference between the import and export of water also can be reduced. Increasing the air relative humidity, the more condensated water on evaporator surface effective, the greater the wetting area. In addition, the heat transfer of latent heat can be increased by the growth of air side and refrigerant side heat transfer coefficient.