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The Basics of How Home Air Conditioning Works


Because air conditioning is something so common in daily life, especially during a hot Tennessee summer, people often don’t think much about how it actually works: that’s something for the experts to worry about whenever an AC starts to malfunction.

Although you should rely on professionals only when you’re in need of air conditioning services in Maryville, TN, our team at MK Russell & Abbott would like to share some of the basics of how an AC actually does its job. This will give you a better sense of what might go wrong with your cooling system and why it is so crucial that you call on skilled repair technicians right away when you sense that your AC has a malfunction.

The first thing you need to know about how an air conditioner runs is that an AC does not create cold air the same way that a furnace or fireplace creates heat. An air conditioner is a type of refrigeration system, and like other refrigeration systems it works by removing heat from an area to lower its temperature. This heat must be shifted to another location as exhaust. This process is called heat exchange and is the basis for how an air conditioner cools down a home.

A standard central air conditioner consists of two units: an indoor unit (the evaporator) and an outdoor unit (the condenser). The condenser contains a compressor, a motor-powered device that changes the refrigerant inside the system from a cool, low-pressure liquid into a hot, high-pressure gas. Most of the energy to run an air conditioner goes to the compressor, which is the central “engine” of the whole system.

The hot, gaseous refrigerant leaves the compressor and travels through the outdoor coils. Outdoor air drawn by a fan in the condenser cabinet runs across the coils, where condensation occurs that releases heat from the refrigerant to the outside. The refrigerant, now cooled, travels toward the indoor unit. On the way, it passes through an expansion valve, which causes it to further drop in pressure and temperature.

When the refrigerant arrives in the indoor coils, it is cold enough to cause evaporation to occur as the warm indoor air crosses it. The refrigerant absorbs heat from the ambient air and lowers the air’s temperature. A blower fan sends this cooled air into the ductwork, where it travels to the various rooms of a house. The warmed, liquid refrigerant now returns to the compressor, and the heat exchange cycle begins again.

Modern ACs are complex machines that rely on a precise balance of components. If you encounter trouble with your air conditioning in Maryville, TN, call MK Russell & Abbott for help. We have provided excellent air conditioning repairs since 1977.