| 摘要 |
PROBLEM TO BE SOLVED: To provide a heat pump water heater achieving reduction of refrigerant usage.SOLUTION: A heat pump water heater includes a heat pump cycle formed by a compressor 1, a radiator 2, an expansion mechanism 3, and an evaporator 4 and a hot water storage tank 6 and is characterized by spirally arranging the radiator 2 on an outer periphery of the hot water storage tank 6 and configuring the radiator 2 by a refrigerant pipe 7 with different inner diameters. An inner diameter of an area in which refrigerant density of the refrigerant pipe 7 to be the radiator 2 in the heat pump cycle, spirally arranged on the outer periphery of the hot water storage tank 6 is low, is made larger than an inner diameter of the refrigerant pipe in an area in which the refrigerant density is high, so that usage of the refrigerant in the area with the high refrigerant density can be reduced. |
