It's a Lubricant. It lubricates parts.
Oil in a AC compressor is there so that the mechanical parts don't over heat from friction
at compressor
right before the compressor
orifice
To prevent wear on the compressor.
to lubricate the compressor
Rejects the heat from the compressor and cold coil (evaporator).
Compressor, condensor, metering device, evaporator.
compressor
To return oil to the compressor.
The refrigeration system used in air conditioners with rotary compressor, the discharged gas is entered firstly into the doom of the compressor, while the system used with reciprocating and other compressors, it is admitted into the discharge tube. and are suction cooled. Why in rotary systems, the discharge refrigerant directly admit into the doom first.