STORAGE TYPE HOT WATER SUPPLY APPARATUS

摘要

PROBLEM TO BE SOLVED: To raise the temperature of hot water in a hot water storage tank and to boil the hot water efficiently by combining heat pump heat collecting operation with solar heat collecting operation. SOLUTION: A heat pump heat collector 21 comprises a closed circuit of a compressor 22, a condenser 23 and an evaporator 25 coupled sequentially in series and filled with refrigerant. A solar heat collector 34 is coupled in parallel with the evaporator 25 such that they can be switched. A heat exchanger 31 exchanges heat between hot water in a hot water storage tank 11 and refrigerant in the condenser 23. A hot water inlet temperature detecting means 44 detects the inlet temperature of hot water entering the heat exchanger 31 from the hot water storage tank 11 and a refrigerant outlet temperature detecting means 45 detects the outlet temperature of refrigerant from the condenser 23. Based on the hot water inlet temperature and the refrigerant outlet temperature, a decision is made which of heat pump heat collecting operation or solar heat collecting operation has higher operating efficiency. The decision criterion for determining the operating system having higher operating efficiency is corrected as required and the hot water supply apparatus is operated according to the determined operating system.