30 May 2005
United Technologies Research Center, under contract to the US Department of Energy, is
performing pre-commercial field trial testing of a commercially sized heat pump water heating
system using CO2 as the working fluid. This system has a nominal capacity of 60 kW and
performance of 3.5 COP at 10ºC water inlet temperature and 10ºC ambient air temperature. As
such, the system is suitable for hotels, restaurants, cafeterias, dormitories, hospitals, laundromats,
and many other commercial and industrial applications. The system is described and operational
experience and economics from field trial sites is presented.