How Does Air Conditioning Work?

How does air conditioning work?

We take air conditioning for granted; it’s just another modern convenience built into most homes. It is considered a necessity, not a luxury, in Southern states, where both the heat and the humidity can be extreme during the summer months. It’s a given in most public businesses, and we have all experienced the welcoming rush of cool air that greets us after a walk across a sizzling hot parking lot. But for all its regularity, its every day existence in the places where we work, shop, and live, many of us don’t truly understand how air conditioners even operate.

The air conditioner dates back to 1902, when Willis Carrier, an engineer, developed a system for controlling temperature and removing humidity for the Sackett-Williams Lithographing and Publishing Company. With his technological know-how and ingenuity, Carrier managed to develop a system that could work not only for large manufacturers hoping to regulate the climate in their production facilities, but also for families wanting to cool their living spaces. While it took many years for air conditioners to be used in homes on a regular basis, the new invention made it possible for more people to relocate to areas of the Southern U.S., as dealing with the warm climate was no longer a major issue.

Carrier essentially took his knowledge of how steam could be used to heat objects and reversed the process. He knew that when a liquid converts to a gas, it absorbs heat. Today, modern air conditioners take advantage of this using four parts: an evaporator, a compressor, a condenser, and an expansion device. Here’s how it works:

How an air conditioner works
Image courtesy of Exploded

Hot air from your home passes over the evaporator coils, which are filled with refrigerant. This refrigerant is able to change from a liquid to a gas fairly easily, so when the hot air passes over the coils, the liquid refrigerant becomes a gas, absorbing the heat from the air. This allows the air to cool, and to flow back into your home.

Simple right?

Sort of. In order for your air conditioner to continue to run, the refrigerant has to change back from a heated gas to a liquid. This is where the compressor comes in. The compressor does exactly what it sounds like it does – it compresses the heated refrigerant gas to a higher pressure, before it moves into the condenser.

In the condenser, heat from the high-pressure refrigerant gas can now be released, thus allowing the refrigerant to again condense into a liquid. Voilà! The refrigerant liquid is now able to move back into the evaporator to cool more hot air from your home.

But…in order to keep everything flowing properly, and to maintain the temperature you want in your home, there has to be some regulation in how much refrigerant can flow through the system. The expansion device allows for that regulation.

When all of these components work together, you have an air conditioner that works perfectly! But when something is wrong with any part of this system, you may end up with an air conditioner that’s less than perfect. If you notice that your home isn’t as cool as it should be, give us a call at (205) 871-8111 to schedule an appointment.