22 May 2002

A6-02 R&D On Heat Pumps With Natural Working Fluids In Japan- E.Hihara (Japan)

The conventional refrigerant R22 has been replaced by hydro-fluorocarbons, and the recovery
and destruction system for fluorocarbons began operation in Japan. However, for future global
warming prevention, it is said that conversion to natural working fluids will be required. In this
paper, the overview of the research on the heat pumps using the natural working fluids in Japan
is summarized. The carbon dioxide systems for mobile air conditioners and water heaters are
actively researched. The heat pump water heaters operated in midnight were put on the market,
and the spread is expected. Hydrocarbon heat pumps for air conditioning are not on the market
from a viewpoint of safety. Only a small amount of refrigerators operated with isobutene is sold
in Japan. Although the ammonia refrigerators are the ripened and reliable technology, the law
requires expensive safety facilities, and therefore they are only used for the low-temperature
warehouse or for the industrial use.