Experimental Study of An Air-Source Heat Pump with Various Ventilation Heat Recovery Methods in Cooling Mode

摘要

Ventilation which exhausts the contaminated indoor air and brings in the fresh outdoor air is essential for maintaining acceptable indoor air quality. Ventilation, however, causes energy loss since heating or cooling is necessary to change the state of outdoor air to that of indoor. In this work, three methods of recovering sensible heat during ventilation and cooling process of air-source heat pump were studied experimentally. Those methods are by a separate sensible heat exchanger, introduction of indoor air to the condenser (single heat recovery), and finally a combination of fore-mentioned two methods (double heat recovery). An air-source heat pump system with none, single and double heat recovery capabilities was built and tested in two constant-temperature and constant-humidity thermal chambers that simulate the indoor and outdoor environments. From the experiment performed under standard cooling condition for various ventilation flow rates, net coefficient of performance was highest in the order of double heat recovery, sensible heat exchanger, and single heat recovery. Double heat recovery heat pump that has the ventilation and double heat recovery functions integrated into a single unit showed the best performance.