In its latest edition, the Japan Air Conditioning, Heating & Refrigeration News (JARN) reports at the beginning of April Hitachi Appliances released three new models of’ commercial heat pump water heating system EcoCute. Being able to supply hot water even if the outside temperature is -20°C, the new models, which include the RHK-1501YJKS with a tank capacity of 560 litres, are suitable for use in northeastern Japan and some regions of Hokkaido. Other major Japanese manufacturers such as Sanyo, Daikin, Panasonic, Melco (Mitsubishi Electric), Toshiba and Corona have launched cold climate models as well.
Energy-efficient and cost-effective in cold climates
All new cold climate models prevent freezing in both units of the EcoCute, the water heating pump and the hot water storage tank, while the compressor operation is constantly controlled in accordance to the outside temperature. These functions ensure a hot water supply at all times even in Japan’s cold regions such as Hokkaido and Tohoku, where the outside temperature can drop to -20° or less.
A special hot water circulation system used in Hitachi’s EcoCute models for mild climate has been adopted for the new models to supply hot water at an optimum temperature even from a shower or faucet located remotely from the water heater. This feature makes the new models suitable for commercial applications such as in hotels. “The ‘internal heat exchanger’ installed in the heat pump unit of the new models efficiently reheats hot water in the water storage tank when the water has cooled after circulating through the water piping, thereby making it possible to keep high-temperature hot water in the pipe”, states the JARN magazine.
The use of heat pump technology enables effective energy savings of around 30% compared to conventional combustion-type water heaters, since the EcoCute models boil water efficiently with less electrical power by using the electricity for collecting the heat of air only.
Future trends for EcoCute
Heat pump technology is gaining momentum in different world regions as it reduces energy costs, while at the same time climate-friendly and sustainable using CO2 as a refrigerant whose ozone-breaking factor is zero.
The Japanese government incorporated the EcoCute into its CO2 reduction programme under the Kyoto Protocol, mandating the installation of 5.2 million units in commercial and domestic properties by 2010. As a result the technology, initially applied for home-use, is also gaining market share in commercial areas, such as restaurants, hotel kitchens, school, hospitals or hair salons. By adding hot water storage units combined with a heat pump, the EcoCute is also able to meet the business needs that require larger amount of water.
Hiroshi Arita, Chief Engineer at Hitachi Appliances Inc. thinks that the replacement of the existing water heaters with EcoCute will be promoted with the popularisation of all-electric homes. He sees the future needs for the EcoCute technology in the reduction of size and weight of the main body to the extent that one or two workers can easily install the Eco Cute. Moreover, the main challenges for all EcoCute manufacturers remains the effort to reduce the costs and to improve the performance even more.