How Does an AC Work?

How Air Conditioners Help Homes and Businesses Stay Cool

In the developed world, it’s rare to come across a home that doesn’t have some form of air conditioning. In some parts of the world - the extreme summer heat in some regions would be unbearable without air conditioning. But despite their prevalence and ubiquitousness, not many people know what makes their AC system tick. 

There’s a common misconception that AC units pull air from outside, cool it down, and pump it indoors. In reality, the process is quite different - and more interesting. Having a general grasp of how an AC system functions can be valuable for preventing problems and troubleshooting any issues that do arise.

Key Parts of an Air Conditioner

While air conditioners vary by size, shape, and design, every system uses the same key components to accomplish the task of cooling and dehumidifying the space it serves. These are the thermostat, blower, evaporator, condenser, compressor, fan, and air filter. Except in the case of window-mounted AC units, these parts are divided between an indoor unit (often referred to as the “blower unit”) and an outdoor unit (often called the “condenser unit”).

The thermostat, air filter, blower, and evaporator are all located indoors, while the outdoor unit contains the condenser, compressor, and fan. The condenser and evaporator both feature copper coils filled with a chemical refrigerant. Copper tubing allows the refrigerant to travel back and forth between the two units in a closed circuit.

How the AC System Works

When the thermostat’s sensor reads that the indoor temperature has risen above the desired temperature, it kicks off the process. The compressor begins pumping the refrigerant in a loop between the units. As the liquid refrigerant enters the evaporator coils, it is converted into gas form, which allows it to absorb heat extremely efficiently. 

Simultaneously, the blower pulls indoor air through the air filter and blows it over the evaporator coils. The air’s heat is transferred to the gaseous refrigerant, while the air’s moisture content collects as condensation on the coils themselves. The blower sends the air back into the home through ducts or a vent on the unit itself.

Meanwhile, the gaseous refrigerant travels to the condenser, where the process is essentially reversed - the outdoor unit’s fan blows air over the condenser coils, and the air itself absorbs the heat collected from indoors. During this transfer of heat, the refrigerant is converted back into liquid form and is then pumped back inside to repeat the process.

The Importance of Professional AC Services

While the general process behind air conditioning is relatively simple, air conditioners are very complicated machines. There’s a big difference between knowing the basics of how they work and knowing how to work on them if there’s a problem. Of course, homeowners can perform basic maintenance tasks like changing the air filter on time and clearing debris away from the condenser unit. But there are numerous other tasks that, if done incorrectly, can damage the unit, or worse, cause serious injury.

That’s why HVAC professionals are highly trained to have a complete understanding of virtually any kind of unit and know how to perform maintenance, repairs, or replacements safely and according to code. For the homeowner, knowledge is power and can help make troubleshooting and even solving minor problems easier, but nothing beats the education, expertise, and experience of a pro.

About Walker Plumbing, Heating & Air

The award-winning Walker Plumbing, Heating & Air has been proudly serving the St. George, Utah community for over 20 years. Their licensed, insured, and background-checked technicians are on call 24/7 to handle any emergency. Walker offers up-front pricing, financing, and a 100% satisfaction guarantee. Give them a call today for air conditioning services in St. George.

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