The GUIDE Japan 2016, published on 28 June, reveals that the ‘EcoCute’ – using CO2 as the refrigerant – has been a runaway success for residential applications in Japan since commercial development began in 2001.

The technology continues to achieve annual sales of between 400,000-500,000 units and CO2 heat pumps have now reached a market share of 98% of all new residential heat pump water heaters in Japan. This growth means that at the end of February 2016, approximately five million EcoCute units were in operation.

The Japanese EcoCute market, worth 56.5 billion yen in 2014, is dominated by four major manufacturers that together have a 90% share of the market: Panasonic, Mitsubishi Electric, Daikin and Corona. The remainder is split between seven other companies.

To put the success of the EcoCute into perspective, annual sales of gas water heaters number between 2,000,000 and 2,500,000 units in Japan. CO2 hot water heat pumps will need to make more headway in this market if they are to achieve a similar monopoly over domestic water heaters to that which they enjoy over heat pump water heaters.

To get there they must reach small households, where reducing initial investment costs would help to increase market penetration. Regulatory measures that disincentivise gas or electric boilers could also create market opportunities for EcoCute technology in homes.

CO2 hot water heat pumps for commercial applications

While the use of CO2 heat pumps in residential applications in Japan is admirable, there remains significant potential for growth in the use of CO2 heat pumps for commercial applications.

The same CO2 heat pump technology that has been harnessed so successfully for domestic purposes in Japan can also be adapted for larger commercial applications. Reduced running costs of up to 61% and CO2 emission reductions of 29% compared to conventional gas boilers are just two of the EcoCute’s benefits for residential hot water heating that can be transferred to commercial properties.

Commercial CO2 hot water heat pumps can be installed in various buildings, for example hotels, hospitals or schools, as well as in spas or food processing facilities. One advantage of CO2 technology is that the water can be heated to high temperatures of up to 90°C, which is particularly handy for sterilising water used in buildings where infection must not spread, such as hospitals and schools. Mayekawa, Itomic, Mitsubishi Heavy Industries and Showa are four prominent suppliers of the CO2 EcoCute for commercial applications in Japan.

CO2 hot water heat pumps can be used in all regions, with field testing having taken place in severe winter conditions in Hokkaido, the northernmost of Japan’s main islands which reaches temperatures as low as -20°C. The results from the field test in Hokkaido were positive, reducing energy costs by 43-54% compared to conventional boilers.

With between 3,000 and 5,000 commercially-sized hot water heat pumps sold every year since 2008 in Japan, this is a significant opportunity for CO2 technology to further penetrate the heating market.

About the GUIDE Japan

‘GUIDE to Natural Refrigerants in Japan – State of the Industry 2016’ is the most recent addition to shecco’s GUIDE series, this time focusing on the key market, technology and policy trends for natural refrigerants in Japan.

The GUIDE to Natural Refrigerants in Japan is now available to download for free at and

Author r744