PURPOSE: To suppress the car manufacturing cost and reduce the power consumption by arranging a blower for a refrigerant condenser so as to also be serviceable for forced ventilation of a car cabin, and adjusting the inner and outer air quantities introduced into a casing using an adjusting means.

CONSTITUTION: An extra-cabin blower 10 and a refrigerant condenser 11 are installed in a casing 12 in a single piece construction, which is provided with an inner air and an outer air lead-in hole 18, 19, and the inner air and outer air quantities to be introduced into the casing 12 are adjusted by changeover dampers 6a, 6b. The extra-cabin blower 10 sends cold wind to the refrigerant condenser 11, and the inner and outer air quantities are adjusted when the inside of the car cabin is ventilated, and inside of the cabin is put in communication with the casing 12, and air stream to an exhaust hole 23 is generated. Thus the extra-cabin blower 10 works both for forced ventilation of inside the cabin and sending of cooled wind to the refrigerant condenser, which should allow suppressing the car manufacturing cost and reducing the power consumption.