ENERGY EFFICIENCY OF ROOM AIR CONDITIONER UNDER VARIOUS OUTDOOR CONDITIONS AND OPERATING MODES
Energy efficiency of room air conditioner for residential house depends much on compressor frequency, the ambient temperature and humidity of the external unit, operation mode and so on. Heating and cooling loads of a house are widely distributed in Japan because occupants normally stop heating or cooling during their absence, and thereby the room air conditioner often operates with low compressor frequency. Efficiency for varying partial load of an air conditioner is hence essential to calculate seasonal energy consumption for heating and cooling. In this paper, we tested a room air conditioner in the experimental house built in an artificial climate chamber and measured the steady-state efficiency in various conditions such as heating/cooling load, outdoor and indoor temperature and humidity and the operating mode. The results clarified that the efficiency and sensible and latent heating/cooling capacity of the tested room air conditioner depended on the conditions and the operating mode, and also clarified that the efficiency especially dropped in intermittent on-off operation and defrosting operation.