HOT WATER SUPPLY APPARATUS

摘要

PROBLEM TO BE SOLVED: To reduce a required power for heating a warm water by heating the warm water with heat absorbed from the atmospheric air and with a supercritical heat pump cycle having a high heat exchange efficiency. SOLUTION: A vacuum double-structured heat insulating tank 300 insulatively stores warm water heated by a refrigerant at the high pressure side of a supercritical heat pump cycle wherein the refrigerant at the high pressure side flows reversely to a warm water flow. Thus the warm water is heated with heat absorbed from the atmospheric air and also with the heat pump cycle 200 having a high heat exchange efficiencyη, thus allowing a required power for heating warm water to be reduced. Thus it is possible to produce warm water even in the daytime with high power rates, thus dispensing with insulatively storing warm water for the daytime use in a large heat insulating tank 300 and the hot water supply apparatus can be installed in a small space.