Why Do Cars Need an AC Compressor and What’s it Do?

For drivers who live in hotter climates or have excessively long summer months, an air conditioner compressor is essential. In reality, an air conditioner alone is promising for most, but a special air compressor is essential to turn that idea into a reality.

The invention of air conditioning did not start with vehicles, which is why AC compressors exist because standard systems aren’t compatible with vehicles. Now that you know air conditioners have more to them than just providing cooler temperatures, it’s time to learn what the AC compressor does.

Refrigerant Importance

Refrigerant is a fluid that ends up turning the hot air into cool air. The importance of refrigerant is similar to oil and antifreeze. Oil is essential for the vehicle to move and also requires a filter to ensure that it performs well while antifreeze allows you to drive during colder weather.

Refrigerant typically comes in R-12 or R134a. While R-12 is the original option, it is now considered unsafe because it uses chlorofluorocarbon fluids (CFM), which has been known to cause ozone layer issues. Therefore, R-134a is considered a safer option, though it still has some chemicals but no significant negative impact on the environment.

AC System Parts

Before you can understand why the AC compressor is essential and how it functions, you must first understand the entire system.


The condenser’s job is to convert hot gas properties into cold fluid. It usually sits in front of the radiator. The air compressor pulls in hot gas, which is radiated by your condenser. The condenser then depressurizes, cools, and liquefies the hot gas for the dryer.


The evaporator focuses on cooling the air and ensuring that there is no moisture in the air. When you turn on the air conditioning, the evaporator focuses on ensuring that you feel cooler in just a few seconds. Another function is to absorb heat from the cabin of the vehicle to ensure the air is cooler throughout the trip.


Once you press the AC button in the car, a clutch turns on the air compressor using electromagnetism. Its goal is to pressurize the refrigerant, allowing it to pass the condenser to reach the evaporator. A cycling clutch switch gauges and regulates the temperature in the evaporator to ensure that the component doesn’t freeze.

Expansion Valve:

The expansion valve, sometimes called an orifice tube, divides the space between the condenser and evaporator. From the condenser, expansion valves gauge heat and pressure and also controls the refrigerant’s pressure.

While they are similar, an orifice tube also focuses to separate impurities away from the system parts.


The accumulator is primarily used with orifice tubes instead of a dryer. The accumulator removes dirt and moisture from the air that goes through the entire system. It can also control the refrigerant that’s about to enter the evaporator. Too much refrigerant can be bad for the AC compressor.


Receivers and dryers work in conjunction with expansion valves to clean away dirt, moisture, and many other harmful substances.

Filtering is essential to remove damaging elements that are airborne and to ensure that no water gets into the air compressor. It also ensures that no moisture can combine with the refrigerant.


The compressor helps the rest of the system produce cold air. Without it, your system could absorb the atmospheric air, but nothing else. In a nutshell, it triggers the AC system to start and keeps the cycles going.


Why Do Cars Need an AC Compressor and What’s it Do?

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