How Does Car AC Works | Everything You Need To Know

The summers are near, and it’s going to be hot. And on the unluckiest day, you’ll have your car heat up like a microwave oven from inside. And you get in, you release how your food feels in the inside of an oven. But wait, there’s an invention that can save you from this misery, a car air-conditioner. 


The car air-condition is a recent innovation of mankind, but refrigerators have existed since the 1800s. It’s the same time, these cooling machines used deadly, poisonous gases as refrigeration, such as Freons. But in 1939, Packard became the first automobile manufacturer to offer an air-conditioning unit in its cars. Since its inception, the car AC has been cooling the interiors and the tempers of millions of car owners. Now, car air-conditioning is one of the standard features in cars these days. But before you stretch your hand and turn on that chilling mAChine, have you ever wondered how a car AC works?



A typical car air-conditioner is composed of three main parts- the compressor, the condenser, and the evaporator. The car AC is a closed-loop of refrigerant that takes the heat, from the cabin, cools it down, and then cools the cabin. Now time for an in-depth explanation.
As we said, it’s a close loop, and there are two sides, a high-pressure side, and low-pressure side or hot side, and a cold side.
Starting from the car AC compressor, which is driven by a belt attached to the car engine. This is where the low-pressure refrigerant is compressed to high-pressure high-temperature gas.


This gas now flows to the condenser, which works like the car’s radiator, it dissipates the heat from the high-temperature compressed refrigerant. This cools the latter, thus the gas now converts to a high-pressure liquid. From here the high-pressure liquid moves over to the receiver dryer before going to the evaporator. The receiver dryer removes any water from the high-pressure refrigerant liquid, which is now pumped to the thermal expansion valve.

From here the high-pressure liquid is allowed to expand and it becomes a low-pressure liquid. It moves to the evaporator, which is located within the vehicle’s interior. By this time, the low-pressure refrigerant liquid has already turn into gas and moves out of the evaporator. At this point, the lower refrigerant liquid again turns into a gas, as it moves out of the evaporator, taking all the heat from the interior of the vehicle.

During this whole process, a fan blows over the exterior of the compressor, blowing cool air into the vehicle’s interior. The low-pressure refrigerant gas enters the compressor, from where the process begins again.

Given below is the representation of the car AC.



Before ending this useful datum on car air-conditioning, let’s answer some FAQs real quickly.


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Is the car AC compressor repairable?


There are various signs to diagnose if your car AC has malfunctioned and needs to be repaired. These signs include.


The inefficiency of the AC to cool down the interiors, and the difference is noticeable. A damaged car AC compressor won’t regulate the refrigerant flow properly, resulting in improper functioning of the AC.

A failing car AC compressor makes a loud noise when the AC is switched on.

Another problematic sign includes the improper functioning of the clutch. It’s not the clutch that engages and disengages the driveshaft. A car AC compressor clutch is used to connect and disconnect drive power to the car’s AC compressor shaft. Unlike a car’s transmission clutch, the car AC compressor clutch either transmits full power or not. A broken clutch means that the car AC compressor is not able to receive any power.

Clogged air-vent can also be the reason for inefficient cooling.

It is also advised to check the fuse box, and also any kind of refrigerant leaks.


Now that we have covered the various signs, let’s get back to the bigger question. The car AC compressor is repairable, but it’s a difficult repair. In any case, replacing the entire option seems to be an easier option. 


Does the car AC compressor have a fuse?



Yes, like many electrical systems on your vehicle, the car AC compressor also has a fuse, and this prevents short-circuits which might lead to a fire. It is located in the car’s fuse panel under the dash or power distribution center under the hood.


How does a car AC compressor work?    



The car AC compressor takes the refrigerant from the evaporator in the loop, which is a low-pressure liquid. It compresses the refrigerant to a high-pressure high-temperature liquid, which eventually converts to gas. It then pumps the gas into the condenser, which then flows to an expansion valve and back to the evaporator. The engine powers the car AC compressor with a belt.


How long does a car AC compressor last?


The car AC compressor is the heart of the air-conditioning system, but like many Accessories on your car, it hard to accurately predict the lifetime of the car AC compressor. It depends on the age of your car and how often you use your AC. Usually, though, you can expect that you will get 8-10 years of use from your AC compressor, and for many drivers, that essentially means the life of the car.


Where is the car AC compressor located?



The car AC compressor will be located at the front of the engine, with the rest of the belt-driven accessories.


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Car AC compressor vs condenser


The biggest confusion in the car air-conditioning system is the difference between AC compressor and condenser, and to remember their functions. The car AC compressor, as the word suggests, compresses the refrigerant from the evaporator to a high-temperature high-pressure gas. While the AC condenser, cools down this high-temperature, high-pressure gas, to just high-pressure gas.



The car air-conditioning is one of the essentials in the vehicle, and majorly during the hottest days of the summers. Thus it’s important to know the nomenclature and the working. And also the signs of trouble, to know if your air-conditioner needs to be repaired or replaced.

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