The true success story of heat pumps in Japan is found in the domestic area. In 2014, a statistic survey showed a market penetration for reversible room air conditioners (ACs), which can be used for heating and cooling, as high as 90%. For every 1000 households, there were 2723 such applications. They are installed in individual rooms, giving the possibility to steer the indoor climate individually. One reason for this wide deployment is the climate in Japan. Over the year, there is need for both heating and cooling, giving reversible ACs / heat pumps an advantage over most alternatives. The environmental effects of heat pumps are considered. In 1999, the Top Runner Program started, aiming at energy savings. This led to a significant efficiency increase, especially during the first ten years. And between 2011 and 2013, the refrigerant used changed from R410A to R32, with one-third of the global warming potential.
Heat pump water heaters were first introduced in 2001. The market grew steadily up until 2010, when it went down for some years. Since 2016, the trend has again been positive, even though the number of sales has not reached the peak value of the year 2010. The natural refrigerant CO2 has been used since the market introduction. This refrigerant performs well when heating water to high temperature in one step. Due to the many bathtubs in the country, this is a coveted capacity in Japan.
Sales of commercial heat pumps had a peak in 1991., Then it suffered a steady decline, decreasing the market with approximately 20%. During the previous ten years, sales have been relatively stable. Just like with room air conditioners refrigerant R32 has been introduced; in 2017 it was used in approximately half of all commercial heat pumps. The reason for the slower introduction is that R32 is mildly flammable, something that is more of an issue in commercial settings as larger amounts of refrigerant is used there.
Industrial heat pumps in Japan are mainly used in production factories. They are applied to food, machinery, chemicals, electronics, agriculture/fisheries, and paper manufacturing in descending order of the number of applications. The market is approximately equally divided between the heat sources air heat sources and simultaneous heating/cooling dual-use technology. The most common refrigerants are R410A, CO2, and R134a.
In the energy conservation measures formulated by the Agency for Natural Resources and Energy all these areas are addressed. The Top Runner Program for the domestic sector is already mentioned. It also includes introduction of high-efficiency water heaters, and appliances in the industrial sector. In the commercial sector, water heaters and refrigerant management technologies are introduced.
Hideaki Maeyama, Japan (Heat Pump & Thermal Storage Technology Center of Japan (HPTCJ))
The text has been shortened by the HPC team