OPERATION CONTROL OF AIR CONDITIONER COMBINED WITH NATURAL CIRCULATION OF REFRIGERANT

PROBLEM TO BE SOLVED: To realize an efficient energy saving operation by executing cooling operation by switching a mode between a complete stop mode, a compressor refrigerating cycle and a natural circulation cycle on the basis of the results of comparison between an indoor temperature, and set lowermost temperature and set uppermost temperature. SOLUTION: When the indoor temperature lowers to be not more than a set lowermost temperature during cooling operation by a natural circulation cycle, an indoor fan 13 and an outdoor fan 14 are stopped to attain a complete stop mode. After keeping the complete stop mode for a given period of time, operation of only the indoor fan 13 is restarted, and if the temperature remains in the level not more than the set lowermost temperature, the complete stop mode is again kept for a given time. On the contrary, if the temperature has become not less than the set uppermost temperature, cooling operation by a compressor refrigerating cycle is conducted. Further, if the temperature falls between the set uppermost temperature and the set lowermost temperature, cooling operation by the natural circulation cycle is conducted, In this way, through the operation of selective switching, detection of indoor temperature can be accurately performed, and thus the compressor is prevented from being operated more than necessary.