Patent ID: 7640763

Claim:
A hot water supply system which, in addition to being capable of operation to supply hot water to a utilization side, is also capable of operation to supply to a heat utilization unit ( 45 ) a heating medium as a heating fluid having an intermediate temperature lower than the temperature of the hot water, the hot water supply system comprising: (i) a heating medium passageway ( 40 ) for causing the heating medium to circulate between the hot water supply system and the heat utilization unit ( 45 ); (ii) a first refrigerant circuit ( 20 ) which performs a refrigerant cycle by causing a first refrigerant to circulate and which heats the heating medium in the heating medium passageway ( 40 ) up to the intermediate temperature by heat exchange with the first refrigerant; and (iii) a second refrigerant circuit ( 60 ) which performs a refrigeration cycle by causing a second refrigerant to circulate and which heats water with the second refrigerant to thereby produce hot water for hot water supply, wherein the second refrigerant circuit ( 60 ) comprises an evaporator which causes the second refrigerant to exchange heat with the heating medium in the heating medium passageway ( 40 ) and which constitutes a heat pump using the heating medium in the heating medium passageway ( 40 ) as a heat source.