How Does Air Conditioning Work? A Step-by-Step Process

You know the feeling. You’re trying to enjoy the outdoors, but you’re hot, uncomfortable, kind of sticky, and desperate for a cool, fresh breath of air. When you just can’t take it anymore, you race inside to feel the crisp, cool air conditioning greet you like a hug. 

Ahhh… that feels better.

Your A/C has saved you from discomfort on even the hottest of summer days. Sometimes, it seems like straight-up magic. But how does air conditioning work? A perfect balance of science and technology helps circulate cool air throughout your home, allowing you to breathe easy and make the most of the short-but-sweet season. Below, find out how air conditioning works.

Step 1: Compressing Cooling Fluid

Air conditioning absorbs heat, cools air, and recycles it throughout your home to maintain a cool and comfortable temperature throughout the house. First, an A/C unit absorbs a bit of heat from the surrounding air to begin slowly cooling down your home. Then, it compresses low-pressure gas—A.K.A., refrigerant—into a hot, high-pressure gas. At this early stage in the process, both temperature and energy begin to rise—in preparation for step two.

Step 2: The Refrigerant Enters the Condenser

As temperature and energy continue to increase, this hot, high-pressure gas enters the condenser. The condenser … well, condenses incoming refrigerant vapor into a liquid, and then uses fins to dissipate the heat. Once the gas turns to liquid, its temperature is much cooler.

Step 3: Evaporation

This is the most important step, because it’s the part of the process that actually cools your home. Once the refrigerant liquid reaches the evaporator, the pressure starts to drop and the liquid slowly starts to evaporate and turn back into gas. Once evaporation takes place, heat is extracted from the surrounding air, dropping the temperature significantly and giving you that chill you love so much.

Step 4: Repeat

The success of your A/C depends on this process repeating itself over and over to not only cool the temperature of your home, but keep it cool as time passes. In this fourth and final step, the refrigerant leaves the evaporator as a chilled, low-pressure gas. The process repeats itself until your home is cooled to your desired temperature. If temperatures once again begin to rise, your A/C saves the day by circling back to step one and pressing on to deliver cool, comfortable air.

How Does Air Conditioning Work? Graphic courtesy of: Air Conditioning & Refrigeration Institute

Sit Back, Relax, and Enjoy the A/C

On those hot summer days when you just can’t seem to escape the sun, nothing feels better than walking into an air-conditioned home. This summer, relax and unwind in comfort knowing your A/C unit has your back. And, next time you’re at trivia, you can wow your friends (and the judges!) with your step-by-step knowledge of how air conditioning works.

Curious about the different types of air conditioners? Read this article to learn about each air conditioner, how they work, and which one is best for your home.