30 November 2015

An Inside Story Behind the Advent of “Eco Cute” CO2 Heat Pump Water Heater for Residential Use

More than ten years have passed since the “Eco Cute” CO2 heat pump water heater for residential use was commercialized in May 2001 in Japan through collaborative R&D including Central Research Institute of Electric Power Industry (CRIEPI). Cumulative shipments amounted to more than 4.6 million at the end of March 2015. There were two projects involving hot water supply heat pumps prior to the development of Eco Cute in CRIEPI, though neither went into commercial production. In this paper, the history and technical aspects of the advent of Eco Cute, including the former two projects, are introduced.