PURPOSE: A heat pump apparatus including a vapor injection compressor is provided to reduce the power consumption thereof and stably provide a hot water supply system by increasing the amount of evaporation in two-pass heat exchangers which function as evaporators. CONSTITUTION: A heat pump apparatus comprises first and second two-pass heat exchangers(120,170), expansion valves(150,155), two vapor injection compressors(110,115), two one-pass heat exchangers(140,145), a heat supply member(280), and a heat supply pipe member(260). The heat supply pipe member includes a heat supply pipe which connects the heat supply member and the two-pass heat exchangers functioning as evaporators and a heat recovery pipe which connects the two one-pass heat exchangers and the heat supply pipe so that the heat of the two one-pass heat exchangers is delivered through the heat recovery pipe and the heat supply pipe to the two-pass heat exchangers.
展开▼
