How Does an Air Conditioner Work?

Summer has arrived with record highs across the country, and with the vast majority of homes having some kind of air conditioner, it’s the most effective way to escape the sun. As you are unwinding in your comfortably cool home or office, appreciating that your air conditioner works, let’s gain some insight at how an average cooling system functions.

The Basics

Your air conditioner runs the similar to your refrigerator, but obviously compared to keeping a small space cool, it has to cool your entire home. Both use a refrigerant that changes easily from liquid to gas, back to liquid again. In your air conditioner, the refrigerant is on a constant ring from the outside to indoors. It goes into the home as a sub-cooled liquid that evaporates and collects or soaks up heat from the air in your home, expands back into vapor, then back to the outside condensing unit where it dissipates the heat and is changed back to a sub-cooled liquid.

The Components

Your AC system is built of four key components: an evaporator coil, a compressor, a condensing coil, and an expansion valve or metering device.

The part where your refrigerant evaporates from a sub-cooled liquid to a super-heated vapor is called the evaporator coil, which may be indoors, in your attic, or situated in the garage. As warm indoor air is blown across the cold evaporator coil, heat is removed from the air…and the cooler air is pushed within your indoor space.

From the evaporator coil, the now super-heated vapor refrigerant goes back to the compressor stationed in your outdoor condensing unit. The compressor enhances the pressure of the vapor until it changes into a hot, high pressure vapor. The now super-hot vapor meets the condenser coil where less hot air blows by the coil, moving heat to the outdoors, and switches the refrigerant to a sub-cooled liquid. The sub-cooled liquid refrigerant is pushed to the indoor evaporator coil where, through an expansion valve or metering device, the process is redone.

Your air conditioner is an endless loop of processes. We realize the important thing to you likely isn’t what happens behind the scenes, but that it’s functioning the right way. If you’d like to know the inner workings or just about keeping cool, give our experts a call at 314-325-7552. We will partner with you and the laws of physics to keep you happy this summer.

Back To Blog