Air conditioning (3): Description and operation (page 2 of 2)

Cooling Unit and Evaporator

1 Evaporator casing 2 Fresh/recirculated air flap motor 3 Pollen filter

4 Evaporator temperature sensor 5 Evaporator matrix

The cooling unit directs the flow of air, from the plenum or the vehicle interior, through the evaporator to the heater assembly.

The cooling unit is installed in place of the air inlet duct used for non air-conditioned vehicles, and contains the evaporator, inlet and outlet pipes connecting to the thermostatic expansion valve through the bulkhead and the evaporator temperature sensor. It also incorporates the water condensate drain and the fresh and recirculated air inlets.

A control flap, operated by a recirculated air motor, opens and closes the fresh and recirculated air inlets. On the downstream side of the evaporator, the casing is lined with polystyrene insulation.