How Does an Air Conditioner Work?

Summer is here with record heat across the country, and with many houses having some kind of air conditioner, it’s the best way to escape the sun. As you are relaxing in your comfortably cool home or office, thankful that your air conditioner works, let’s gain some insight at how an average central heating and cooling system works.

The Basics

Your air conditioner operates the just like your refrigerator, but clearly rather than keeping a small space cool, it has to work to cool down your whole house. Both use a refrigerant that converts swiftly from liquid to gas, back to liquid again. In your air conditioner, the refrigerant is on a regular circle from the outdoors to indoors. It goes into the house as a sub-cooled liquid that evaporates and collects or soaks up heat from the air in your home, expands back into vapor, then heads to the outside condensing unit where it dissipates the heat and is transferred back to a sub-cooled liquid.

The Components

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

The piece 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 located in the garage. As warm indoor air is blown across the cold evaporator coil, heat is detached from the air…and the cooler air is blown among your home.

From the evaporator coil, the now super-heated vapor refrigerant flows to the compressor stationed in your exterior condensing unit. The compressor raises the pressure of the vapor until it changes into a hot, high pressure vapor. The now super-hot vapor goes into the condenser coil where a smaller amount hot air blows past the coil, moving heat to the outdoors, and returns the refrigerant to a sub-cooled liquid. The sub-cooled liquid refrigerant is returned to the indoor evaporator coil where, through an expansion valve or metering device, the process is replicated.

Your HVAC system is an endless loop of physics at work. We know the important thing to you might not be how your AC operates, but that it’s working the right way. If you’d like to know the inner workings or just about remaining cool, give our technicians a call at 205-208-8090. We will partner with you and the laws of physics to confirm you cool this summer.

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