PURPOSE: To enable an energy saving operation to be carried out without deteriorating a feeling of air conditioning by a method wherein a variation of a cooling load is read in response to a variation of an amount of state of a refrigerant and a target value of an air conditioner is varied.
CONSTITUTION: A position X of a temperature setter 9, a high pressure refrigerant pressure Pd and a low pressure refrigerant pressure Ps from pressure sensors 81 and 82 are read into a computer 72 of a controlling unit 7. When T'set for calculating a first target temperature Tset and a second target temperature T'set is exceeded, a second target temperature is changed over to a target value T. That is, a first controlling means may read first target temperature Tset from a temperature setting unit 9, a temperature Te of cold air from a cold air temperature sensor 91. A variable volume mechanism 11 of a compressor is controlled in such a way as a cold air temperature is coincided with target temperature. A second controlling means may read a high pressure refrigerant pressure Pd and a low pressure refrigerant pressure Ps from the pressure sensors 81 and 82. When the values of Pd/Ps exceeds a predetermined value, a signal for varying a target value T of the first controlling means is sent to the first controlling means.
KAWAI TAKAMASA
SAKA KOICHI
