Given the hot summers in various regions, you probably know some basics about air conditioners, but do you know how air conditioner evaporators work?

If the inner workings of your air conditioner are a mystery to you, you'll benefit from knowing some technical details about how your cooling system works.

No matter how much your air conditioner is running, it's important to perform routine air conditioner maintenance to keep the evaporator, as well as the rest of the system, running efficiently.

If something does go wrong, you'll be better able to fix it. Your knowledge will also help you make an informed choice when you're ready to buy replacement components or upgrade your air conditioner.

Air conditioners don't actually "produce" cold air the way a furnace produces heat. Instead, they use refrigerants or coolants to absorb heat from the air, take the heat outside, and release it into the outside air.

The refrigerant keeps circulating to remove more and more heat from your home until your indoor air temperature reaches the setting on the thermostat.

Evaporator and condenser coils handle different aspects of the cooling cycle. Let's start by looking at the evaporator coil.

The evaporator coil of an air conditioner, also known as the evaporator core, is the part of the system where the refrigerant absorbs heat. This is where the cold air comes from.

The evaporator coil is located in or near the air handler where the blower is located. Evaporator coils are made of copper, steel, or aluminum because these metals conduct heat easily. Most residential AC evaporators consist of tubes bent into a U shape and installed in panels.

Panels are usually positioned with an "A". These panels are lined with thin metal sheets called fins that cool the passing air closer to the coils to maximize the effectiveness of the refrigerant.

When the air conditioner is running, the compressor draws cold, low-pressure liquid refrigerant through pipes in the evaporator coil. The refrigerant passes through an expansion valve before entering the evaporator coil. The valve relieves the pressure of the liquid refrigerant, allowing it to cool rapidly. The liquid refrigerant leaving the expansion valve is so cold that it can absorb heat from the air.

The expansion valve also controls how much refrigerant flows into the evaporator. More advanced expansion valves, such as thermostatic expansion valves (TXVs), can precisely control flow to improve the overall energy efficiency of the system.

As the refrigerant flows, the blower draws hot indoor air into the evaporator coil. The refrigerant absorbs heat from the air passing by, heating up and evaporating in the process.

When the water vapor from warm home air hits the cold evaporator coil, it condenses into a liquid and drips into the condensation pan, draining the water outside. This is how evaporator coils reduce humidity in your home.

Because of the way they operate, evaporator and condenser coils need to be kept clean to function as intended and for optimal energy efficiency. Dirty evaporator coils can experience several problems, including:

Impaired heat absorption and cooling capacity

Higher energy usage

Higher pressure and temperature

Frost and icing

Even a layer of fine dust on the evaporator coil can reduce its efficiency. The dust acts as an insulator, keeping the heat inside and keeping the air away from the cold coil. This means that the coils cannot absorb as much heat as they are cleaned. Your system will then have to run longer to deliver the indoor temperature you want, which means it will use more energy.

Because it doesn't absorb enough heat, the refrigerant flowing through the dirty evaporator coil doesn't heat up as much as it should. This cold refrigerant causes water vapor in the air to freeze instead of condensing into a liquid. Eventually, the entire evaporator coil will get frosted.

A layer of frost on the evaporator is never normal. Running your system with a refrigerated evaporator will raise the temperature in the compressor and eventually cause that component to fail.

Dust on the evaporator coil, debris on the outdoor condenser, dirty air filters, and refrigerant leaks can all cause the evaporator to freeze. If you are unable to identify the problem, contact a heating and cooling technician.

Evaporator coils can also develop tiny pinhole leaks due to corrosion from moisture from condensation mixing with chemicals commonly found in household air. Oily residue around the evaporator or in the drain pan indicates that your coil has a leak and needs to be replaced.

The chemicals in the air that fuel these leaks are called volatile organic compounds (VOCs), and they come from new carpets, upholstery, pressed wood furniture, air fresheners, cleaning chemicals, and many other sources. Ensuring good home ventilation reduces VOCs in indoor air, protecting evaporator coils and your health.

The above briefly introduces the working principle of the air conditioner evaporator. If you want to buy an air conditioner evaporator or other air conditioner accessories, please contact us.

ComforPlanet is a professional custom air conditioners and accessories manufacturer. We are committed to the business philosophy of "customer first, people-oriented, leading quality, leading technology, and continuous profit growth" to create a trustworthy brand image and a respected public image. Our mission is to allow everyone around the world to breathe clean and comfortable indoor air.