Automotive Air Conditioning Terms

Accumulator: The accumulator is located at the evaporator outlet. Its function is to separate liquid retained from vapour, retain the liquid and release the vapour to the compressor.

Ambient Air: Air outside the vehicle.

Compressor: Component that pumps refrigerant gas and increases the pressure and temperature of the gas vapour.

Condensate: Water taken from air. It forms on the exterior of the evaporator.

Condenser Component of an air conditioning system which turns the refrigerant vapour back to liquid by removing heat from the vapour.

Conditioned Air: Dry, clean air.

Contaminants: Anything other than the gas and oil that is in the air conditioning system. Such as moisture, dirt, rust and air.

Cycling Clutch System: Term referring to the system control, provided by the engaging and disengaging of the compressor.

Evacuate: To create a vacuum within a system.

Evaporator: Component of an air conditioning system which conditions the air. The liquid refrigerant is evaporated into a vapour in this component.

Expansion Valve: Controls the flow of liquid refrigerant to the evaporator, were it changes state to a gas.

Liquid line (High Side): Connects the condenser outlet to the evaporator inlet. High pressure liquid gas flows through this line.

Muffler: Device to minimise pumping sounds from the compressor.

Orifice Tube: Fixed calibrated tube were liquid refrigerant from the high pressure area is forced through to the low pressure area.

Receiver Dryer: Stores liquid gas and oil. Contains a drying agent (silica gel) It removes the moisture from the liquid as it passes over the drying agent.

Stores and dries liquid refrigerant before it goes to the expansion valve.

Schrader Valve: A spring loaded valve where a connection can be made to the refrigerant system. There is one on the high side and one on the low side.

Suction Line (Low Side): Connects the evaporator outlet to the compressor inlet Low pressure vapour flows through this line.

Thermostat: A component used in a cycling clutch system to engage and disengage the compressor. It prevents water condensate from freezing on the evaporator core and controls the temperature of air that flows from the evaporator.

Trinary Switch: Three level pressure switch, gas pressure above 2 bar will engage compressor and disengage above 27 bar at 16 bar will engage condenser fan and disengage at 11 bar.

Climate Control: This name is given to a system that automatically maintains as close as possible the interior temperature of a vehicle against the desired temperature set by the occupants.