A compressor capacity control with an inverter, has been considered from the viewpoint of high energy saving in a refrigerating cycle. However, the system has not been put into practical use because of high initial cost, technical problems of electronic parts, and complexity of system control. In this connection, we developed the new inverter--controlled heat-pump air conditioner by using the latest electronics and refrigeration technology .

This paper discusses the trend of energy saving in air conditioners in Japan and the objectives of developing the inverter controlled air conditioner . It also discusses the following items with respect to the inverter controlled air conditioner and the effects of employing an inverter .

1. Inverter for air conditioner
2. Refrigerating cycle
3. Air conditioner control with inverter

Units: Dual