Huang B.J.Lin F.H.2019-06-262019-06-2619979.78079E+12https://www.scopus.com/inward/record.uri?eid=2-s2.0-84928494281&doi=10.1115%2f97-AA-026&partnerID=40&md5=f8481c583023d94af77c789e7e0902cdhttps://scholars.lib.ntu.edu.tw/handle/123456789/411456A compact and fast temperature-response heat pump water heater was designed using multiple tanks and a sequential control device. The supply tank was heated as a priority by a freon-line switching device to increase the temperature recovery speed. A dual-tank prototype with 100- liter capacity was built and tested. The experimental results show that the time for temperature recovery of the supply tank from 42°C to 54°C reaches 10-20 minutes and COP reaches 2.0-3.0 during various seasons. The prototype tests show that an energy saving around 50%-70% as compared to the electrical water heater can be obtained. The hot water discharge efficiency of the heat pump is 0.912. Copyright © 1997 by ASME.[SDGs]SDG7Energy conservation; Hot water distribution systems; Pumps; Solar water heaters; Tanks (containers); Water heaters; Electrical water heater; Heat pump water heater; Heat pumps; Line switching; Prototype tests; Sequential control; Temperature recovery; Temperature response; Heat pump systemsconference paper10.1115/97-AA-0262-s2.0-84928494281