June 21, 2021
Central Air Conditioning in Shawnee, Kansas

Have you ever felt the cool breeze of an air conditioner and wondered how it actually works? AC units are fascinating pieces of technology that provide efficient and convenient cooling. Various AC models may use slightly different parts and components. However, the majority of air conditioners will use these steps to cool the air in your home.

The Thermostat Realizes It Is Too Hot

The first and most essential step in any air conditioner is simply turning the unit on. Modern AC units are regulated by a thermostat. This thermostat will constantly measure the air temperature inside of your house. When the temperature is higher than your preferred setting, an electrical relay will be triggered. This tells the AC unit to start running. It will continue running at the same steady, even pace until the thermostat sees that its target temperature is reached.

Fans Pull Warm Air Into the Unit

Now it’s time to get the air moving. Your air conditioner will have multiple fans placed at key points throughout the system. These fans are used to pull hot air from your house into the return vent. This big vent allows your AC unit to continuously take in hot air that would otherwise linger and make your residence feel sticky and warm.

Warm Air Moves Over the Evaporator

The fans then blow the warm air over the evaporator in your air conditioner. The evaporator is a big coil of metal that contains liquid refrigerant. Refrigerant is a special chemical that is essential to running any AC unit. This supercooled liquid will suck up heat from its surroundings. As your hot air blows over the evaporator, the refrigerant removes the heat, and your air gets nice and cool again. Excess moisture builds up on the evaporator coils, where it drips down to a drain line. The drain line will carry the water outside of your house, where it can drain away safely.

Cold Air Blows Through Your Home

Once the air has been cooled by your evaporator coils, fans push it back into your home. In most AC units, the cold air will travel through ducts in the walls, attic, or basement. Then, they will blow out through supply vents positioned around the house. If you place your hand against one, you will feel the cool breeze. This means your air conditioner is working. In some types of AC units, your cold air might skip the journey of going through ducts. Some single-room units will just blow the cold air directly back to you.


Hot Refrigerant Flows to the Compressor

The cooled air in your AC unit might have already blown back into your home, but what about the heat that was removed? This heat was absorbed by the refrigerant liquid in your evaporator coils. As the liquid gets hotter and hotter, it turns into a gas. This warm, low-pressure gas travels through a line all the way to the compressor unit outside. This unit compresses the refrigerant, turning it into a high-pressure gas.

The Condenser Cools the Refrigerant Back Down

At this point, your refrigerant is too warm to keep your residence cool. To get back to this point, the refrigerant has to travel through the condenser. The condenser is a big outdoor box that is filled with a network of pipes. The refrigerant travels over these pipes, releasing heat. This extra heat is expelled outside. On its journey, the refrigerant will lose some pressure and turn back into a liquid before it moves back indoors.

The Expansion Valve Cools the Refrigerant

The refrigerant has one final step to go through before it gets back into the evaporator coils and starts the cycle all over again. After leaving the condenser coils, the refrigerant travels through an expansion valve. This is basically a very narrow hole. It slows down the flow of the refrigerant liquid, which ends up reducing the pressure of the liquid. At lower pressures, the refrigerant becomes even chillier. It is finally ready to start cooling air in your home again, so it returns to the evaporator.

Interested in learning more about your AC unit? Air Care Heating & Cooling is here to answer any questions you might have. Our team can assist with all sorts of AC repairs, HVAC maintenance, and heating installation jobs in Shawnee and the surrounding areas. We also offer indoor air quality services and water heaters.

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