Development of CO2 heat pump water heater for residential use

Abstract

In Japan, the demand for hot tap water accounts for about 30% of residential total energy consumption, but most of this demand is met by direct combustion of fossil fuels. Thus, the development of a high-performance heat pump water heater for energy conservation is expected. On the other hand, the development of heat pumps with natural refrigerants is expected for environmental protection. Thus, the world's first CO₂ heat pump water heater for residential use was developed.