The Compressor is known as the “heart” of air conditioning system. It creates the heat by developing an extremely high pressure in the air conditioning refrigerant. As the pressure and temperature are related, we can see how high pressure refrigerant is actually hot.
The A/C Compressor consists of the compressor itself and the clutch assembly which is a combination of three parts; the hub, pulley, and coil. It consists of 2 ports, an inlet and outlet, or ‘suction’ and 'discharge' respectively. The suction port is, always has the hole of larger diameter. Refrigerant is 'sucked' into the compressor, compressed, and 'discharged' through the outlet, headed for the condenser. The complex series of passageways, valves, bearings, and other components are present inside the compressor, including several types of pumps i.e. piston type, rotary vane, and scroll.
Howbeit, before buying, A/C compressors three elements must have kept in mind Quality, Reliability and Value. The famous A/C compressors from all over the world are Denso, Direct Industry, Danfoss, etc.