A compressor having a compression mechanism within a housing for compressing a refrigerant gas according to the rotation of a rotary shaft operatively connected to an external power source. A pulley is mounted on the rotary shaft and located on one side of the housing for transmitting power from the external power source to the shaft. A fan sends air to the outer surface of the housing by rotating with the pulley. Heat transferring fins are provided on the housing adjacent to the fan.