Alternatives to HCFCs in the Refrigeration and Air Conditioning Sector 60 S ection 02 Fig. 2.17 The CO2 hot water heater pumps have a design very similar to the external part of a split air conditioner. O ne of first mass-produced products with CO2 as a refrigerant was a heat pump marketed under the name Eco-cute™, which was introduced on the market 2001 designed for hot water production by the Denso Company in Japan. This heat pump was developed through a project sponsored by utility companies and the government to reduce the energy consumption for domestic hot water production. In 2005, there were 225 000 of these heat pumps supplied to the Japanese markets through several of the leading brands. There were several cultural and 2.6 Carbon dioxide heat pumps for domestic heating and tap water The ClimaCheck™ Performance Analyser was set up to monitor the refrigerant charging process and the general operating condition of the water chiller. The machine was operated under controlled speed conditions after injecting the first liquid charge directly at the large liquid line drier Schrader valve connection. This was done after ensuring that the chilled water pumps and condenser water pumps were operational and that the cooling towers were also functional. As the operating conditions settled towards normal levels, it was immediately apparent that discharge temperature was low when compared to that of refrigerant R-22. While it was too early to finalise the commissioning and associated readings at this point, the first impressions were very favourable. The refrigerant charge and superheat was gradually adjusted and came under excellent and steady control initially to 7°C. The final refrigerant charge was recorded at 61kg, but this was with only one of the two compressors running and then at only 780 rpm, as opposed to its full capability of 1800 rpm.A validation of the commissioning at high ambient will be done with the ClimaCheck™ Performance Analyser and if required adjustment of the refrigerant charge to meet higher load conditions. Su mmary Heat pupump used for heating and hot water production with supercritical operaration with COCO2 (R-744) There is much interest in carbon dioxide as a low-GWGWP refrigerant that can replace CFCs, HCFCs and HFCs as an alternative refrigerant with a lower impact on the environment. The discussions focus on which applications CO2 can be used with a good energy efficiency as the indirect contribution to the global warming from the consumed energy is significantly bigger than that of the refrigerant. A low-GWGWP refrigerant is preferable when it can be used with comparable energy efficiency. The ongoing research and field tests are now focusing on establishing the application where the technology has reached a level where it can compete as an environmentally good and cost effective solution. In several applications CO2 has reached acceptance in the market. Background data/information for this case on CO2 heat pumps comes from Yang Chen, from the Department of Energy at the Royal Institute of Technology in Stockholm [Yang et al. , 2009] NB:The description is based on the data received from the researcher, but as regards the selection of information and interpretation, the responsibility is with the author of this report.