| 摘要 |
PROBLEM TO BE SOLVED: To improve overall operating efficiency while reducing the possibility of occurrence of hot water shortage.SOLUTION: A heat pump storage water heater includes: a hot water storage tank 6 for storing hot water; a heating circulation circuit 29 for circulating hot water from a lower portion of the hot water storage tank 6 to an upper portion of the hot water storage tank 6; heat pump type heating means 2 disposed in the middle of the heating circulation circuit 29 to heat the hot water in the hot water storage tank 6; a feed water temperature sensor 14 for detecting a feed water temperature or an outside air temperature sensor 41 for detecting an outside air temperature; a plurality of hot water storage temperature sensors 15 arranged in the hot water storage tank 6 to detect a hot water storage temperature; and control means 30 for performing an additional heating operation for increasing hot water storage amount by operating the heat pump type heating means 2 when the hot water storage temperature sensor 15 detects that the hot water storage amount in the hot water storage tank 6 satisfies a predetermined additional heating start condition in a specific time zone. When the feed water temperature or the outside air temperature is lower than a predetermined value, the control means 30 changes the additional heating start condition to a condition in which starting of additional heating is facilitated compared to when the feed water temperature or the outside air temperature is equal to or higher than the predetermined value. |
