parts of a car's air conditioning

The Main Parts of a Car’s Air Conditioning System

In order to maintain climate control in your vehicle, it is critical to have at least a basic understanding regarding the main parts of a car’s air conditioning system. In addition to the main parts of a car’s air conditioning system, it is important to know how your interior HVAC system works. For, there may be times when your A/C is not blowing cold or not blowing cold enough. In some cases, the blower fan itself does not work at all. At times the servos can stick, especially on older vehicles, and mislead you to believe that you have an A/C malfunction. In any case, you can always find the parts you need at PartsMax.

The Main Parts of a Car’s Air Conditioning System Available from PartsMax

There are essentially three different types of automotive A/C systems that are only slightly different. They all have a compressor, condenser, and evaporator. The variance comes in whether they have an orifice tube, an expansion valve, or both. The accumulator and receiver/dryer play similar roles. The filters, hoses, and belts play an obvious role which requires little discussion.


The receiver/dryer is a canister filter that is often mounted to the condenser or en route to the expansion valve. It acts as a storage device for refrigerant in times of low demand. It contains a desiccant to remove moisture from the A/C system that can corrode and damage it. It also contains oil to lubricate the system. It is mounted on the high-pressure side of the compressor.


An accumulator is used in A/C systems that use an orifice tube. Orifice systems use higher volumes of refrigerant that do not fully vaporize before they reach the compressor. The accumulator serves an important function in warming up this liquid into vapor so that it can safely enter the compressor. It acts as a storage chamber, filter, and oil reserve. It also contains a desiccant to remove moisture from the system. It is mounted on the low-pressure side of the compressor.


The compressor works like an air compressor by increasing the pressure of the vapor refrigerant when the clutch is activated. It is typically driven by a drive belt that is connected to the engine pulley or serpentine belt drive system. It pulls in the refrigerant after passing through the evaporator and pumps it to the condenser.


The condenser is often mounted on the fan shroud of the vehicle in front of the radiator. The vapor from the A/C compressor passes through the narrow passages of finely finned tubing to condense into a liquid. The finned tubing is a thermal exchange that dissipates the heat of the vaporized refrigerant into the atmosphere. The air passing through the grille of the vehicle and the cooling fan lower the temperature of the condenser to make the vapor condense instantly.


The evaporator is located in the interior and acts as another type of heat exchanger. The interior blower fan passes cold air over the thin aluminum finned tubing to fill the interior cabin with refrigerated air.

Thermal Expansion Valve/Orifice Tube

The expansion valve and orifice tube essentially act like nozzles to atomize the liquid refrigerant before it passes into the evaporator. The type of gases that are used in the A/C system (ammonia, R-12, R-22, R-134a, etc.) share a unique natural property of becoming extremely cold when converted into gases. This is the magic that makes air conditioning systems work so miraculously.