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.