How Does a Car’s Air Conditioning Work?

Car's Air Conditioner

Summer is almost here, and with that comes the heat. Heat can make driving your car unbearable, which is why air conditioning was introduced by Packard in 1939. Beginning in luxury vehicles and now expanding into almost every vehicle produced, air conditioning has been cooling drivers and passengers for decades.

What Does Your Car Air Conditioning Do?

Your vehicle’s air conditioner has two main purposes. It cools the air entering the passenger compartment and removes the moisture from the air so it feels more comfortable inside your car.

In many makes and models, air conditioning cycles automatically when the defrost setting is chosen. The humidity from the windshield is pulled to improve your visibility. Cold air is usually not required when the defrost setting is selected, which is why it is crucial to know that air conditioning functions even when the heat is selected on the heater control.

So, How Does it Work?

Components of a Car’s Air Conditioning System

Your car’s air conditioning system consists of a compressor, a condenser, an evaporator (or drier), refrigeration lines and a couple of sensors and valves.


The compressor is the heart of your vehicle’s A/C system. It is what takes the refrigerant (commonly called Freon) and pressurizes it so it will cool the air. It’s run by an engine belt. The compressor also has a clutch (or on some vehicles, a solenoid) that is electronically operated. This clutch turns the compressor on and off as you demand more cool air.


Similar to a radiator, the condenser is typically mounted at the front of the car right next to the radiator that cools the engine. It will sometimes have its own electric cooling fan, too. The hot, compressed air passes through the condenser and gets much cooler. As it cools, it becomes a liquid.


The evaporator is another miniature radiator that does just the opposite task as the condenser. As the super-cool liquid is passed through its tube, air is forced through and gets extremely cold, right before it hits your face. As it warms up again, the refrigerant begins turning back into a gas.

Thermal Expansive Valve

You don’t always want cooler air—especially during the winter months—so the A/C system has a valve that controls the flow of super-cool refrigerant to the evaporator. This allows you to regulate how cold the air blowing on you gets. There are a few types of valves in use currently, but they all do the same thing.

Driver or Accumulator

The accumulator, also known as the receiver-drier, is somewhat the safety catch for your system. The compressor is only supposed to compress the gas form of refrigerant, but there’s always a chance that some liquid could make it back that far. This liquid is caught by the drier before it can damage your compressor. Even the smallest leak or careless installation can introduce water moisture to the system, so the drier absorbs this chemically, using what’s called a desiccant (similar to that packet of “DO NOT EAT” that comes with electronics, or in a bag of beef jerky). The drier also consists of a filter that catches any gunk that might be in there.


Different systems also have sensors to tell it pressure and temperatures, but they are unique to a make and model of vehicle. If you need some work done on your car’s A/C system, don’t hesitate to contact us here at Asher Automotive with the link below!

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