How Air Conditioners Actually Work
Quick Basics

Air conditioners are one of the most important appliances in any home. They keep us cool and comfortable during the hot summer months, and we couldn’t live without them! But how do they work? In this article, we will take a look at the science behind air conditioning and how it keeps our homes cool.

It’s Just A Phase…

Air conditioners work by converting the air inside your home from a liquid to a gas. This process is called phase conversion, and it is how air conditioners are able to cool the air. Liquid to gas conversions actually absorbs heat. In other words, these conversions take the heat out of your immediate environment. To accomplish this, the air conditioner in your home forces special compounds to evaporate and condense through a series of coils, over and over again.

What’s In The Special Sauce?

These special compounds (responsible for phase conversion) are known as refrigerants. In other words, the refrigerant is the substance inside the air conditioner’s coils that helps to convert the air from a liquid to a gas, thus absorbing heat. Once this heat is trapped, it’s pushed outside the unit. But to understand this, we need to dig deeper into the specific roles of both the compressor and coils in an air conditioner.

How Air Conditioners Actually Work
Photo of part of the air conditioner coils found in HVAC units

Two Types of Coils

First, the coils are responsible for cooling as the refrigerant moves through them – which then absorbs the surrounding heat as a fan pushes air over them. They are typically made of copper or aluminum.

There are two types of coils, though, and their purposes are inversely related to each other. The evaporator coils specifically are responsible for trapping heat as the refrigerant turns from a liquid into a gas. The condenser coils, by contrast, allow for the refrigerant to turn back into a liquid state, thus expelling the extracted heat. A fan then pushes this out off the condenser coils.

But how does the gas turn back into a liquid?

The Compressor

The compressor is responsible for condensing the gas back into this liquid state, thus giving off the heat as the refrigerant continues to move through the air conditioner. This portion of the operation is typically located outside of your home so heat is not re-added to the area it’s extracted from.

Refrigerants are pumped through your evaporator coils, absorbing heat. This is then compressed and forced out of the system through condenser coils, and blown out of your home. In this way, we are able to remove heat from closed spaces and push it outside of the space through our understanding of phase conversions.

Air conditioners are a complex piece of machinery, but they are essential for keeping our homes cool and comfortable during the hot summer months. In this article, we have taken a look at the science behind how air conditioners work. We hope you have found this informative and you now have a better understanding of how these appliances work!

Air Conditioner Compressor

Call the Professionals

HVAC systems are complex so you should leave checkups and repairs to the professionals. Even with a new system, it is important to have biannual services done to make sure your system is running properly. If there is an issue, the technician will be able to identify and correct it before it causes a system failure, costing you thousands of dollars to replace. Regular maintenance will also save you money on your monthly energy bill by keeping your system running at peak performance. 

If you would like to schedule routine maintenance for your HVAC system or are curious about our service packages, visit or call Gnoth & Lukowski Heating & Air Conditioning LLC at (574) 287-3550. We have been serving the South Bend-Mishawaka area for over 30 years and offer 24-hour emergency repair services at no extra charge.