To save energy consumption by connecting an air heat exchanger 5 for collecting heat from outside air in series to an air heat exchanger 6 for collecting heat due to ventilation from a living room for smoothing the evaporation of a refrigerant even at a lower outside air temperature in a winter season to improve the operation result coefficient of a heat pump.

A compressor 1 and a water heat exchanger 3 are arranged on a known refrigerating cycle and an air heat exchanger 6 is installed between the air heat exchanger 5 and the compressor 1 for collecting ventilation exhaust heat, thus smoothing the evaporation of the refrigerant.