Your air conditioning system plays an integral part in the comfort, health, and happiness of your entire family. After all, we can depend on a well-maintained, functional, and efficient AC system to keep our indoor environment cool and comfortable during hot, humid weather without spending a fortune on our utility bill each month.


By drawing heat energy out of the house and replacing it with cooler air, the air conditioner isan integral part of your home’s entire central heating and cooling system. Aside from changing the indoor temperature, this powerful appliance can also regulate the humidity and enhance indoor air quality. 

Everyone knows that air conditioners can make a room cooler, but not everybody knows exactly how it works. The process of making the air cooler is similar to the way your refrigerator keeps your food cold and is actually based on a fairly simple scientific concept. In this article, our expert team of AC specialists from Four Seasons Heating and Air Conditioning will explain how this appliance works to make your living or working environment more comfortable—and why regular AC maintenance from a reliable Chicago air conditioning company is crucial for keeping it running at top speed throughout the year.

What’s in an AC?

The air conditioner contains chemicals that can convert gas to a liquid and vice versa. These chemicals are among the key components that enable the transfer of heat energy inside your home to the outdoors.

The most important components of an AC are the evaporator, compressor, condenser, filters, the expansion valve, the muffler, and the thermostat. Each part plays an essential role in the process of extracting hot air, cooling it down, and re-circulating the colder air throughout the home.

How Does it Work?

So here’s what happens—the cooling liquid (known as the refrigerant) first goes to the compressor as a low-pressure gas. As the name suggests, the compressor will forcibly compress the molecules such that they are packed closer, and the temperature and pressure rise.

This hot gas then exits the compressor and moves on into the condenser. Similar to how a car’s radiator works, the metal fins at the outside of your air conditioning system allow the heat to be dispelled fast. Because of the high pressure, the gas also transforms into a liquid. By the time the fluid leaves the condenser, it is already much cooler. This fluid flows into the evaporator through a tiny hole, and when it hits the other side, the pressure will decline, and evaporation into gas will occur. 

A Cyclical Process: How Air Circulates Through Your AC

During the whole process, heat is extracted from the indoor air in order to separate the liquid molecules into gas. The evaporator’s metal fins also contribute to the exchange of heat energy. The whole process repeats when the refrigerant comes back to the compressor. The fan attached to the evaporator is what allows the indoor air to circulate well inside the room and across the metal fins. The air conditioner also sucks in air, which cools the gas in the evaporator, through the vent. 

From the vent, the air then enters the duct system, which will also be the component that will blow the air back out into the house after it is transformed into cooler air. The thermostat is what regulates the temperature inside your home by detecting if the indoor temperature is already at your preferred level. 

The air conditioner will be shut off automatically when the optimal temperature is achieved and will be turned back on when the room becomes hotter. 

Ensuring Your Air Conditioning Works Efficiently

For more than four decades, Four Seasons Heating and Air Conditioning has been a trusted Chicago air conditioning company in Chicagoland, providing comprehensive HVAC services that help homeowners maintain a comfortable living environment for themselves and their families.

From 24-hour emergency AC repair services to scheduled AC maintenance, Four Seasons Heating & Cooling keeps your HVAC system running smoothly throughout the year. Aside from repair and maintenance, we also install new air conditioners and provide ductless cooling. If you want to learn more about our services at Four Seasons Heating and Air Conditioning, contact us today or fill out this quick online form to book a no-obligation, in-home estimate.