Air conditioning (Refrigerant system): Description and operation

Refrigerant system

Schematic of air conditioning system

1 Evaporator 2 Thermostatic expansion valve 3 Low pressure servicing connection 4 Outlet to rear A/C system (where fitted) 5 Dual pressure switch 6 Receiver drier 7 Cooling fan 8 Condenser 9 Compressor

10 Inlet from rear A/C system (where fitted) 11 High pressure servicing connection 12 Air flows a Ambient air b Cooled air c Ambient air through condenser 13 Refrigerant a Liquid b Vapour

The refrigerant system transfers heat from the vehicle interior to the outside atmosphere to provide the heater assembly with dehumidified cool air. The system comprises a compressor, condenser, receiver drier, thermostatic expansion valve and evaporator, joined together by refrigerant lines. The system is a sealed, closed loop, filled with a charge weight of R134a refrigerant as the heat transfer medium. Oil is added to the refrigerant to lubricate the internal components of the compressor.