PURPOSE: To reduce the number of item of parts by coupling the upper flow-in port of an evaporator to the discharge port of a blower unit, also coupling the flow-in port of a heater unit to the lower flow-out port of the evaporator and thereby increasing the part common to both left- and right-side steering automobiles.

CONSTITUTION: The blower unit 2 and the evaporator 3 are arranged in an engine room and the upper flow-in port of the evaporator 3 is coupled to the discharge port of the blower unit 2 through the intermediary of a blower duct 11. Meanwhile, inside a passenger room 4 is arranged an intake box 12 connected to the heater unit 5 and the blower unit 3, while to this intake box is coupled the lower flow-in port of the heater unit 5 which has defroster blow-out ports 13a and 13b on both sides of its upper surface, a ventilator blow-out port 10 on the upper surface of the rear part and blower blow-out ports 14a and 14b on both sides of the lower part. By this constitution, by rearranging the blower unit 2, the blower duct 11 and the intake box 12, the device can be applied to both left- and right-side steering automobile.