Abstract
The purpose of this study is to reveal energy performance and thermal comfort of a mini-split heat pump air conditioner during heating season. We have measured energy consumption and thermal environment of a room where the air conditioner was installed. The room was in a climate chamber and air temperature in the chamber was controlled as average outdoor air temperature of Osaka in January. The mini-split heat pump air conditioner worked with maximum COP during 20% partial heat load with intermittent heating. The average COP was about 3.65, compared with its standard COP 4.18 in this operation.