| 摘要 |
PROBLEM TO BE SOLVED: To provide a heat pump water heater excellent in energy efficiency.SOLUTION: This heat pump water heater includes: a hot water storage bath 1 for storing hot water heated by a heat pump unit 2; a heat exchanger 11 which is arranged outside of the hot water storage bath, and uses hot water stored inside the hot water storage bath as a heating medium on the high temperature side; outgoing tubing 20 for supplying hot water from the hot water storage bath to the heat exchanger; return tubing 22 for returning hot water from the heat exchanger to the hot water storage bath; hot water output tubing 16 for outputting hot water from the hot water storage bath; water supply tubing 14 for supplying the hot water storage bath with water; and bypass tubing 19 which is branched from the water supply tubing, and is connected to the hot water output tubing, wherein a heat-accumulating unit 4 for heat transferring between the return tubing and the bypass tubing is provided, whereby an input water temperature into the heat pump unit is dropped to enhance heat exchange efficiency of a heat pump, and further water is heated by use of heat-accumulated thermal energy to decrease an amount of boil-up hot water, thereby enhancing energy efficiency. |
