The compressor pumps Ball Sockets low temperature refrigerant gas and compresses it into high pressure, high temperature gas. The refrigerant is sent to the condenser in front of the radiator, where the condenser removes some of its heat through the ambient air passing through its fins, turning the refrigerant from a hot gas to a warm liquid. In an expansion valve A/C system, warm liquid moves through a receiver dryer that removes moisture to maximize the efficiency of the refrigerant's heat exchange capacity.
The refrigerant then passes through the expansion valve, which has a sense line connected to the suction port of the A/C compressor, keeping it under pressure. In an orifice system, warm liquid refrigerant flows directly from the condenser to the orifice. The orifice system uses a clutch to maintain pressure at the air conditioner compressor suction to cycle the compressor on and off. The expansion of the hot liquid through the expansion valve or orifice tube causes a drop in pressure and therefore a drop in temperature.
The air from the passenger compartment then passes through one side of the coil in the evaporator and the low temperature liquid refrigerant through the other. The refrigerant removes heat from the air in the passenger compartment and returns to the suction port of the air conditioner compressor as a low temperature gas. In an orifice tube system, the accumulator located between the evaporator and the air conditioner compressor suction has a dehumidifying desiccant, just like the accumulator drier used in expansion valve systems. However, it also collects any unevaporated refrigerant to prevent liquid lock of the compressor.