To prevent the temperature of a discharging pipe from being increased and reduce a consumption of electricity by a method wherein the number of rotation of a cold air circulating fan motor and the number of rotation of a compressor or the number of rotation of a compressor cooling fan motor are determined in response to either an outdoor temperature or a refrigerator load.

A mean current flowing into a compressor 1 is detected by a compressor current detecting means 12 and there is provided a compressor continuous operation time counter 13 to acknowledge a continuous operation time of the compressor 1. Then, it is decided by a temperature discriminating means 11 whether or not an outdoor temperature is higher than or lower than a set temperature, and a current value of the compressor 1 and a continuous operation time of the compressor 1 are determined by an operation determining means 14 and further each of the number of rotation of the cold air circulating fan motor 13, the number of rotation of the cooling fan motor 2 and the number of rotation of the compressor 1 is determined. Then, each of the numbers of rotation of these members is changed by means 15 for changing the number of rotation of the cold air circulating fan motor, means 16 for changing the number of rotation of the compressor cooling fan motor and means 17 for changing the number of rotation of the compressor in response to this determination.