Abstract: Currently,the energy recovery rate of fresh air heat recovery system is about 50%-60%.The summer fresh air temperature is higher than indoor,winter fresh air temperature is lower than indoor,which disturb the stability of the indoor thermal environment.This paper proposes a new compound air heat recovery system whch combine wheel with heat pump,and test the basic properties of the summer working conditions of the system.Results show that compared with the wheel separate operation mode,in the wheel with heat pump operation mode,after the indoor ventilation and fresh air exchanging heat in the wheel,condenser cooling load is reduced,the compressor power consumption is reduced,fresh air load is greatly reduced after wheel cold recycling,energy saving effect is remarkable,and can effectively decrease the temperature of fresh air,to achieve the design requirements.The difference of fresh air humidity and indoor humidity is not large in the two kinds of operation mode,to air conditioning rooms which have low requirements for indoor humidity,the two operation modes are reliability;the proportion of heat recovery energy and equipment energy consumption in compound air heat recovery system is higher than single wheel heat recovery system,and less affected by the indoor exhaust air temperature and humidity,which has a lot of energy saving efficiency.

Key words: compound, fresh air, heat recovery, wheel, heat pump