Compressor HVAC: Description and Operation

Compressor







The compressor circulates the refrigerant around the system by compressing low pressure, low temperature vapour from the evaporator and discharging the resultant high pressure, high temperature vapour to the condenser.

The compressor is attached to a mounting bracket on the engine, and is a ten cylinder swash plate unit with a fixed displacement of 177 ml/rev (0.19 US qt/rev). The auxiliary drive belt drives the compressor via a pulley and an electrically actuated clutch. Operation of the clutch is controlled by the Engine Control Module (ECM).

To protect the refrigerant system from unacceptably high pressure, a pressure relief valve is installed in the outlet side of the compressor. The pressure relief valve is set to operate at 34.3 to 41.4 bars (497 to 600 psi) and vents excess pressure into the engine compartment.