How Does an Air Conditioner Work?
Surprisingly, your air conditioner doesn’t create cold air—it removes heat from your home. In this video, we’ll dive into the inner workings of an air conditioner and explain how it keeps your space cool. Air conditioning is essential for keeping your home cool and comfortable during the hot summer months. But how does an air conditioner actually work? Understanding the mechanics behind air conditioning can help you make informed decisions about maintaining, repairing, or replacing your system. Let’s take a closer look at the process that makes your indoor environment so refreshing.
The Basic Function of an Air Conditioner
At its core, an air conditioner doesn’t just pump cool air into your home; instead, it removes heat from the air inside your house and transfers it outside. The process involves several key components working together to provide cool and comfortable air. These include the evaporator, compressor, condenser, and expansion valve, along with a refrigerant that circulates through the system to facilitate heat exchange.
Step-by-Step Air Conditioning Process
1. Warm Air is Drawn Inside
When your home’s temperature rises above the level set on your thermostat, your air conditioning system kicks into action. Warm air from inside your home is drawn into the air conditioner through return ducts. This warm air is then passed over the evaporator coil, which contains refrigerant. The goal here is to cool the air by removing the heat it carries.
2. Heat Absorption by the Evaporator Coil
The refrigerant inside the evaporator coil is a cold, low-pressure liquid. As the warm air flows over the coil, the refrigerant absorbs the heat from the air, causing the refrigerant to evaporate and turn into a gas. This phase change is a crucial part of the cooling process, as it allows the refrigerant to carry the heat away from your home. The air that remains after this heat exchange is cooler and is blown back into your living spaces through supply ducts.
3. Compressing the Refrigerant
Once the refrigerant absorbs heat and changes into a gas, it flows to the compressor, located in the outdoor unit of your air conditioning system. The compressor’s job is to pressurize the refrigerant gas, which increases its temperature. By compressing the refrigerant, the system makes it easier to transfer the heat to the outdoor air. The compressor acts like a pump, continuously moving the refrigerant through the system to maintain the cooling cycle.
4. Releasing Heat to the Outdoors
After the refrigerant is pressurized, it flows to the condenser coil, which is also located in the outdoor unit. The condenser coil facilitates the release of heat into the outside air. As the refrigerant passes through the coil, outdoor air flows over the coil, and the refrigerant releases the absorbed heat. This process turns the refrigerant back into a liquid, and the outdoor fan helps dissipate the heat away from the unit. At this stage, the refrigerant has returned to a cooler state, ready to absorb more heat from inside your home.
5. Expansion Valve and Repeating the Cycle
Before the refrigerant can return to the evaporator coil, it passes through an expansion valve. This valve lowers the pressure of the refrigerant, causing it to cool even further and revert to a low-pressure liquid. The refrigerant then flows back into the evaporator coil, where the cycle begins again, constantly removing heat from your home and releasing it outdoors.
The Importance of Refrigerant in Cooling
Refrigerant is a vital component of your air conditioner, enabling the entire cooling process to take place. It absorbs and releases heat as it changes states between liquid and gas. However, refrigerant levels can deplete over time due to leaks, resulting in inefficient cooling and increased energy consumption. It’s important to ensure that your air conditioner has the proper refrigerant levels to maintain optimal performance. At CES Heating & Air Conditioning, we offer comprehensive refrigerant checks and repairs to keep your system running efficiently.
Dehumidification: A Bonus of Air Conditioning
In addition to lowering the temperature in your home, air conditioners also help control humidity levels. As the air cools, the moisture it carries condenses on the evaporator coil. This reduces indoor humidity, making your home feel more comfortable, especially in regions with high humidity levels. Lower humidity not only improves comfort but also helps prevent issues like mold growth and dust mites.
The Role of the Thermostat in Air Conditioning
Your thermostat plays a central role in controlling your air conditioning system. It monitors the temperature in your home and signals the air conditioner to start cooling when necessary. Modern thermostats are often programmable or equipped with smart technology, allowing you to set specific temperatures and cooling schedules that fit your lifestyle. By optimizing your thermostat settings, you can save on energy bills without sacrificing comfort.
Maintaining Your Air Conditioner
To ensure that your air conditioner operates efficiently throughout its lifespan, regular maintenance is essential. Routine inspections and tune-ups can catch small problems before they turn into costly repairs, extend the life of your unit, and improve overall efficiency. At CES Heating & Air Conditioning, we provide expert maintenance services to keep your air conditioner in top condition. From cleaning coils to checking refrigerant levels and replacing filters, our technicians ensure that your system delivers reliable cooling when you need it most.
Trust CES Heating & Air Conditioning for Your Cooling Needs
At CES Heating & Air Conditioning, we understand how important it is to have a fully functioning air conditioning system, especially during the hottest months of the year. Whether you need installation, repair, or routine maintenance, our team of experienced professionals is here to ensure your home stays cool and comfortable. We take pride in delivering high-quality HVAC services tailored to meet the unique needs of every customer.
Bill and his crew did a stellar job installing a Mitsubishi heat pump into my shop. They came in right on budget and upgraded the unit free because the one I selected was out of stock. Communication was flawless throughout the process, they cleaned up after themselves and my shop is much more user-friendly now. Thanks Bill!
Bill was great to work with, he’s a genuine, knowledgeable guy. He had great advice for our setup. I felt like I was in good hands the whole time working with him. I was shocked that this company does work in Newcastle, Wa, it’s quite a hike from Lake Stevens. Michael, Anthony, and Kaben(spelling?) installed my 3 units. There were a couple would be mistakes but this crew made sure anytime they had a question or concern to double check. This meant that everything was installed properly and those mistakes weren’t made. I would 100% work with these folks again and I’d recommend them to anyone else. Great team, great company.
Cascade Energy Services recently installed a Mitsubishi heat pump and minisplit system at my house, and I am very pleased with the experience. Bill handled the sales process gracefully and was always available to answer questions. I received two competing quotes for this service, and only Bill's ideas for how to solve the problems posed by the old house made sense. The installation team was friendly, efficient, and communicated well. They respected the space, keeping it clean and handling tricky issues effectively. I'll definitely contact Bill and his team for any future heating and AC needs.
HIGHLY recommend!!! Bill and his team are the literal best. So knowledgeable, not out to scam people out of money. He saved us money! No sales gimmicks, no pressure. Definitely calling them for all future projects. They came highly recommended by a friend, and I am so thankful we went with Cascade.
High-quality, professional work for a reasonable price.
We had a nuisance popping breaker that another vendor failed to fix after replacing the breaker, and was glacially slow to respond to our requests to come back out to investigate the issue further. CES came out and was able to fix the issue. They even gave us their number so that they could come by again that same day if it started popping again.
I cannot recommend Cascade Energy Services enough. Bill and his team were professional, warm, and friendly. Their estimate on our AC install came in much lower than other companies in the Lake Stevens area. Thanks guys! Much appreciated!!
Bill and his team are going to treat you right and his tech. Anthony are so professional I will definitely use them and let anyone know if they need or want service done get ahold of them 👍
Words can't describe how great this team is. One of the last honest, trustworthy companies in the Seattle area. Bill and their team installed our tankless water heater as well as our ductless mini-split. They also did an amazing job when we later needed to add a new mini-split unit to another bedroom. They have been trusted for year in our house for the maintenance and service of those units. What you won't get from Cascade energy is an upsell to sell more product. Bill clearly cares about his team, and his team even told me about how they had a company outing to a Portland Trail Blazers game (not easy to do). Hard to find that kind of business these days who cares about their team and lets that culture trickle down to how they treat their clients. You won’t be disappointed with their team.
CES Heating & Cooling

Cascade Energy Services strives to be better each and every day. Our business model is based on honest and ethical practices.

Respect for your home is paramount to us. That means using drop cloths, shoe covers, cleaning up fingerprints and vacuuming up all debris and materials each and every visit. We do the work contracted to us to the best of our abilities, as clean and crisp as humanly possible.

Cascade Energy Services also believes in giving back to our community and helping those less fortunate than us. We believe that to be successful in life and in business, you must reach out and give back.
For All Your Electrical Needs Visit Our Sister Company, CES Electrical Services!

- Electrical repairs and installations for homes and businesses
- Wiring and rewiring for new construction or renovations
- Lighting design and installation
- Generator installation and maintenance
- Panel upgrades and replacements
Bane and the crew from Casacade Energy Services did an excellent, professional installation of our new Trane furnace (nice and quiet!), along with a house surge protector and earthquake cutoff mechanism for our gas line. Bill was courteous, knowledgeable and very helpful. Also, his office staff helped us through all the warranty work and helped answer questions about rebates. We couldn't ask for a better experience. We will be using them for the annual furnace check up. Thanks, Bill and crew!