01 November 1985

Electric Heat Pumps for Retrofit in Existing Small Residential Buildings (Hydronic Systems) – National Position Paper – Japan


The paper includes dat on climate, housing circumstance, cooling/heating systems, heat pump room air conditioners, heat pump chillers, annual sales, energy supply costs, and investment costs. The paper concludes that heat pump room air conditioners (HP-RAC) have recently gained a large market along with the improvement of HP performance. Behind the steady development lie such factors as Japan’ climatic characteristics, house construction, family composition, unique living custom, etc. These circumstances have aroused the necessity of cooling, as well as heating featuring and individual system, intermittent operation, orientation towards forced convection, and simple installation work. Due to these requirements for both cooling and heating, the Japanese market has been formed in relatively mild regions where there are more than 30 cooling days/year and less than 2500 heating degree days (D18-18). According to an estimate, HP-RAC sales for fiscal 1984 will reach 1,750,000 units accounting for 61% of total RAC shipments (2,850,000 units). In order to expand the market up to the semi-cold regions, where there are about 3000 heating degree days, or up to 3500 degree day regions, it is required to lower the limit of commercia feasibility of outside temperatures to – 15 C. form the current limit – 10 C., and alias to develop a water source system, a bivalent system, a more efficient heat accumulation technique, etc. The trade is proceeding with R&D in these areas.


  • You can order this document

    Documents of interest can be orderd by filling out the form below.

    Note: some publications are chargeable. You can see the price in the field below.

  • This field is for validation purposes and should be left unchanged.