| 摘要 |
PURPOSE:To perform energy-saving room heating in a heat pump type air conditioner by comparing the difference between the atmospheric temperature and the coolant evaporation temperature of an outdoor heat exchanger with the prescribed value and producing a defrosting cycle command in accordance with the compared result, thereby effectively detecting the frost. CONSTITUTION:A heat pump type air conditioner feeds high temperature coolant by a compressor (not shown) through a pipe to an indoor side heat exchanger 5 at the heating time, heats the indoor air, and condenses the coolant. Then, the coolant is reduced under pressure bya capillary tube 7, is evaporated by an outdoor heat exchanger 8, and is returned to a compressor. In this case, the outputs of a coolant temperature sensor 18 attached to the heat exchanger 8 and an atmospheric temperature sensor 19 are inputted to a detection controller 23, which obtains the temperature difference between after heating operation starts and after the prescribed time. Then, the temperature difference and the temperature difference betwee the prescribed times when a frost is expected are varied, and a defrost cycle command is produced when the difference exceeds the set variation amount. |
