AIR FLOW CONTROL UNIT OF CAR HEATING UNIT

PURPOSE:To prevent a temperature difference from occurring between the front and rear of a car compartment by adjusting the air flow through front heater outlet ports and rear heater outlet ports in accordance with the difference between sunlight quantities of the front and rear of the car. CONSTITUTION:A control circuit 2 determines the difference between sunlight quantities of the front and rear of a car based on detection signals of sunlight quantity sensors 1a, 1b provided on the front and rear of the car, and controls dampers 4A, 4b of front heater outlet ports 3a, 3b and dampers 5a, 5b of rear heater outlet ports 6a, 6b respectively to predetermined damper apertures through servo circuits 7 in accrodance with the difference between the sunlight quantities. In this case, the control is performed so that the air flow through the heater outlet port with the larger sunlight quantity is reduced.