How Does an Air Conditioner Work?

July 18, 2016

The summer season is in full swing with record temps across the country, and with many houses having some kind of air conditioner, it’s the most effective way to beat the heat. As you are unwinding in your comfortably cool home or office, appreciating that your air conditioner works, let’s take a peek at how an average central heating and cooling system works.

The Basics

Your air conditioner works the just like your refrigerator, but clearly instead of keeping a little space cool, it has to effectively provide cooler air to your whole 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 circle from the exterior to indoors. It goes into the home as a sub-cooled liquid that evaporates and assembles or soaks up heat from your indoor air, expands back into vapor, then back to the outside condensing unit where it dissipates the heat and is switched back to a sub-cooled liquid.

The Components

Your AC system is created out of four critical pieces: an evaporator coil, a compressor, a condensing coil, and an expansion valve or metering device.

The component where your refrigerant evaporates from a sub-cooled liquid to a super-heated vapor is called the evaporator coil, which may be inside, in your attic, or located in the garage. As warm indoor air is blown across the cold evaporator coil, heat is pulled from the air…and the cooled air is blown throughout your indoor space.

From the evaporator coil, the now super-heated vapor refrigerant goes back to the compressor based in your outside condensing unit. The compressor increases the pressure of the vapor until it turns into a hot, high pressure vapor. The now super-hot vapor enters the condenser coil where a smaller amount hot air blows across the coil, removing heat to the outdoors, and returns the refrigerant to a sub-cooled liquid. The sub-cooled liquid refrigerant is sent to the indoor evaporator coil where, through an expansion valve or metering device, the process is repeated.

Your AC system is an endless loop of processes. We understand the important thing to you likely isn’t what happens behind the scenes, but that it’s functioning successfully. If you’d like to think about the process or just about remaining cool, give our experts a call at 636-206-4250. We will work with you and the laws of physics to ensure you happy this season.