Thermostatic Air Cleaner: Description and Operation

TAC Operation:

A heated intake air system is used to give good driveability under varying climatic conditions. By having a uniform inlet air temperature, the fuel system can be calibrated to reduce exhaust emissions and to eliminate throttle blade icing. The TAC air cleaner operates by heated air and manifold vacuum. Air can enter the air cleaner from outside the engine compartment or from a heat stove built around the exhaust crossover pipe. A vacuum diaphram motor, built into the air cleaner housing, moves a damper door, to admit hot air from the heat stove, cold outside air, or a combination of both. Inside the air cleaner is a temperature sensor that reacts to air intake temperature and controls the amount of vacuum going to the motor.

Hot Air Delivery Mode:

^ When the temperature is below 86~F (30~C), the sensor allows vacuum to the motor and the damper door will be up, shutting off outside air and allowing only heated air from the exhaust heat stove to enter the air cleaner.

Outside Air Delivery Mode:

^ When the temperature is above 131~F (55~c), the damper door drops down and only outside air enters the air cleaner.

Regulating Mode:

^ Between 86~F (30~C) and 131~F (55~C) the damper door allows both heated and outside air to enter the air cleaner.