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How Do AC Compressors Work?

June 28, 2024
How Do AC Compressors Work?

You’ve probably heard that AC compressors are the most important parts of air conditioning systems, but how do they work? 

In this post, we’ll cover all the details you need to know.

How Air Conditioning Compressors Work in Five Steps

It’s hard to designate any part of air conditioning systems as the most important, but AC compressors have a pretty strong case. They are the focal point of the cooling process, pulling all the strings (mostly the refrigerant in this case) to ensure efficient heat absorption.

Here’s an abridged version of what happens inside your air conditioner when it’s running and how AC compressors help:

Step 1:

Warm air from your home enters the indoor unit, flowing over the evaporator coil. The coil contains cold, low-pressure refrigerant. The warm air blowing over the coil will lose its heat to the refrigerant and slowly turn into gas.

Step 2:

The gaseous refrigerant containing the heat absorbed from your indoor space flows into the compressor. Once in there, the compressor squeezes the refrigerant vapor, increasing both its temperature and pressure.

Step 3:

The compressor pushes the hot, high-pressure refrigerant to the condenser unit which houses the condenser coils. The coils lose the absorbed heat to the outside air. The fan in the outdoor unit helps speed up this process. With the heat lost, the condenser will turn the refrigerant into a high-pressure liquid.

Step 4:

The liquid refrigerant will pass through an expansion valve, which will cause the pressure to drop and significantly lower the refrigerant’s temperature.

Step 5:

The cool, low-pressure refrigerant will re-enter the evaporator coil, ready to absorb more heat from your indoor air again. The cycle will continue until you turn off the air conditioning unit.

It’s clear to see the importance of AC compressors in the cooling process. Without these components, there’s no way to regulate refrigerant pressure and flow.


How Do I Know My Air Conditioner’s Compressor Is Working?

If your air conditioner’s compressor is working, you’ll hear a consistent buzzing sound coming from the outdoor unit. Some of the buzz will come from the fan next to it, but the outdoor unit will be a lot quieter if the compressor is bad.

Perhaps the most straightforward sign of compressor issues is that your unit will not deliver any cool air.

Is the Outdoor Unit the AC Compressor?

The outdoor unit houses the compressor and other components. The compressor is a component that has a cylindrical shape (like a small gas tank). The size will depend on whether you have a split system, a portable air conditioner, or ductless mini split air conditioners.

How Long Do AC Compressors Last?

AC compressors can last the entire lifespan of the AC. Therefore, you can expect yours to last up to 15 years with regular maintenance, depending on the system’s efficiency ratings.

Get Further Guidance From Your Local Experts

Do you need to learn more about AC compressors? Do you need help choosing the right AC compressor system for your home?

Call the Chilly Ben’s Heating & Air Conditioning team at 270-776-3691 to schedule a consultation.

About The Author

Chilly Bens

For 14 years, Chilly Bens has been providing heating and air conditioning service to the Central Kentucky area. 

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