How does a car’s air conditioning system work? Is it virtually the same as all other A/C systems? When you put your hand on those vents, how is the air so perfectly wintry? Amazingly, there are many phenomena that function consistently every time you crank up that A/C. Learn some of the major ones below!

1. Compression

Before any of the cooling occurs, a whole lot of compression must come first. An A/C compressor typically takes a refrigerant and compresses it so that the gas is under high pressure. Once this high-pressure refrigerant moves through the high-pressure tube, it comes in contact with the condenser. Because A/C compressors are often powered by engine-accessory belts, a worn-out belt can interfere with the functionality of the compressor.

2. Condensation

Many of us know condensation as a main player in the hydrologic cycle. In an automobile’s A/C system, condensation occurs inside the A/C condenser, where the gaseous refrigerant is exchanged with the warm cabin air. Located between the grille and the radiator, the A/C condenser should be kept clean; a clogged condenser or a malfunctioning cooling fan can cause a decline in the coolness of the air. A leaking condenser would mean the loss of the refrigerant, and therefore a less effective exchange between the cool and the warm air.

3. Evaporation

After passing the high-pressure tubing, the refrigerant (in liquid form at this point due to condensation) comes across the orifice tube (also called a thermal expansion valve). Because the orifice tube permits only a little bit of refrigerant to pass at a time, the pressure is relieved, and the refrigerant transforms back into a gaseous form. This dramatic pressure reduction cools the refrigerant. And as the refrigerant evaporates back into gas form due to the hot air, the heat from the passing air gets trapped and the air becomes chilly.


Today, achieving the perfect arctic cool is possible with a simple turn of a knob or a press of a button; contrary to its effortless appearance on the outside, however, the A/C system’s inner workings are quite intricate. To find out about more about automotive A/C systems or discuss any troubles you have with them, ask away at H.W. Automotive Inc.!