Most consumers, and many mechanics think the AC Compressor makes the A/C in your vehicle cold. That’s simply not true. Although this is a common belief, the A/C Compressor actually creates heat as well as high pressure. When the A/C Refrigerant is under high pressure, it is hot. The cool effect is actually created elsewhere, and we will talk about that in just a bit.
Your A/C Compressor also has an Air Conditioning pulley, or AC Clutch. In the AC Compressor, there are two ports. One is the Suction port and the other is the Discharge Port. The Suction Port is the Inlet, and is the bigger diameter of the two. The Discharge Port is the Outlet and is the smaller port of the two. Air Conditioning Freon is suctioned into the A/C Compressor, then it is further compressed, and lastly it is discharged out of the outletport of the Compressor. Your Air Conditioning AC Compressor encases a variety of components that allow the refrigerant to enter, compress and then exit the A/C Compressor.
The A/C Clutch is at the very front of the AC Compressor, and consists of a Hub, Pulley and Coil. The Hub is at the very front part of the Compressor and is what engages physically engages the internals. The Compressor Pulley is where the belt sits, and the Coil is the electronic part that engages the hub. Once the A/C Compressor is engaged, the inside components begin to move the Freon through the A/C Refrigerant system.
Turning whenever then engine is cranked, the A/C Compressor Clutch Pulley will spin even if the AC Compressor is off. If the A/C System is turned on, power is sent to your A/C Compressor Clutch and it will then engage. However, if the pressure in the system (or the refrigerant level) is either too low or high, switches will kill power to the Compressor to keep from damaging it.
Keep in mind, most late model vehicles use the A/C system for Defrost Mode. That’s because the air conditioning system is not just for cooling, it’s also for dehumidifying.
Once your AC Compressor is engaged, it brings the lower pressure freon in, and ironically compresses it. Your refrigerant then moves into the AC Condenser. In the Condenser, refrigerant moves through the small tubes in the A/C Condenser. Air that blows through the Condenser helps to cool down the refrigerant pressure. When your vehicle is moving at higher speeds, the natural movement of the outside air does a good job at cooling the freon. When an automobile is not moving, the Fan Clutch or Cooling Fan Assemblies engage to move air through the A/C Condenser. Once the Refrigerant is cooled down, it then moves towards the Evaporator. Prior to entering the Evaporator, it must move into an Expansion Device. As the refrigerant travels through the orifice in the expansion device, it is restricted. As the refrigerant passes through this orifice, it expands very quickly, and turns to very cold liquid.