Compressor HVAC: Description and Operation

- The compressor is driven by a belt on the engine when the A/C clutch engages (A/C on).
- Low pressure refrigerant from the evaporator is compressed by the compressor. After compression, the refrigerant (now high pressure) flows to the condenser.
- The compressor contains refrigerant oil (PAG oil) that can be mixed, at all temperatures, with R-134a refrigerant.
- A label on the compressor indicates that compressor is for R-134a systems only.