Power-saving control device for air-conditioning system

In a power-saving control device for an air-conditioning system according to the present invention comprising an air-conditioning duct having an air flow passage formed therein, a variable-capacity compressor that allows the output capacity with which a compressed coolant is output to be varied and an evaporator that is disposed inside the air flow passage at the air-conditioning duct, receives the coolant output from the variable-capacity compressor via a pressure-reducing device and performs heat exchange between the low-temperature, low-pressure coolant supplied thereto and air flowing through the air flow passage, and adopting a structure enabling power-saving control through control of the output capacity of the variable-capacity compressor, a dew-point temperature is calculated based upon a factor correlated to generation of odor from the evaporator, a critical evaporating temperature to constitute a threshold of the odor generation is determined based upon the dew-point temperature and the evaporating temperature is adjusted to a higher level or a lower level relative to the critical evaporating temperature. In the air conditioning system utilizing a variable-capacity compressor, power-saving control on the variable-capacity compressor is achieved while preventing or reducing the extent of odor generation from the endoergic heat exchanger provided within the air-conditioning duct.