Your AC coils are a big part of making sure your home stays cool on hot days. In a traditional split-system HVAC device, you’ll have an indoor and outdoor unit each containing one coil. Within the indoor unit of the system you have the evaporator coil, responsible for absorbing heat and humidity from your home. Within the outdoor unit of the system you have the condenser coil, responsible for releasing that heat and humidity outside, so it doesn’t get stuck in the air conditioner or your home.

The two coils form one continuous loop and, without them, heat and humidity would never escape your home, which could make it uncomfortably warm when you want it to be cool. Because the coils are such an important part of the air conditioner, keeping AC coils clean is crucial. While AC coil maintenance is dangerous and should only be handled by a licensed HVAC technician, there are a few safe tips and tricks you can perform yourself to make sure your coils stay in tip-top shape.

Why keep AC coils clean?

It’s important to schedule regular maintenance on your air conditioner, which includes AC coil maintenance, to ensure your unit is running at the best of its ability. When your air conditioner coils are dirty your entire unit will run less effectively, it will take longer and cost more to get your home to your desired temperature, and eventually, the entire unit may be compromised.

What problems can arise from dirty coils?

• Decreased AC efficiency: The primary function of your air conditioner is to absorb heat and humidity from your home and release it outside to ultimately cool your home. The AC coils are a crucial component in this process. When the coils are covered in dust, dirt, debris, or anything else, the unwanted particles form an insulating layer around the coils. This blocks the coils from the surrounding air, which makes the cooling process longer and harder for the air conditioner to perform, resulting in your home staying at an undesired, warm temperature for long periods of time.
• Increased cooling costs: No one wants a high energy bill, but if your AC coils are dirty, it’s likely that it will affect your statement. When coils are dirty, it takes longer to complete the heat transfer process, which means your air conditioner needs to run for longer to get your home to your desired temperature. The longer your air conditioner is on, the higher your energy costs.
• Larger system repairs or replacement: Going too long without having your AC coils professionally cleaned and maintained might result in larger problems with the unit and could eventually force you to replace your system entirely. For example, dust and dirt build-up on your evaporator coil means the refrigerant running through the coil won’t be able to warm up as much as it’s supposed to, which causes the water vapor to freeze instead of becoming a liquid. A frosted over AC coil won’t be able to absorb heat correctly, which could eventually cause the entire unit to break. Other issues that can arise from dirty AC coils and lead to larger system malfunctions are the compressor overheating and leaks forming in the coils.

Types of air conditioner coils

Like we mentioned earlier, two types of coils live in your unit— the evaporator coil and condenser coil. Each coil plays an important role in cooling your home and keeping it at the temperature you desire.

The evaporator coil is responsible for absorbing heat and humidity from your home so it can be transported through the rest of the air conditioner and eventually released outside the home. It’s located inside the home and is normally made out of a metal that conducts heat very well, like copper or steel.

The condenser coil is on the other side of the heat exchange cycle. This coil is responsible for releasing the heat and humidity from your home outside, so it doesn’t get trapped in the air conditioner and ultimately in your home. Both the condenser coil and the evaporator coil work on a continuous cycle until your home reaches your ideal temperature.

AC coil maintenance

Your AC coils are fragile parts of your air conditioner that can bend or break with very little force. Plus, they can be hard to access (especially the evaporator coil, which is located inside the home). This means, the majority of coil cleaning and maintenance should be left to a licensed HVAC professional to avoid damaging your unit or hurting yourself.

Find Local AC Coil Cleaning Services

Cleaning AC coils with compressed air

A licensed HVAC professional will turn your unit off and carefully blow air through the coil in the opposite direction of how it normally flows in order to clean the coils with compressed air. As a result, anything stuck on or around the coil will get blown to the top, where the HVAC technician will remove it. This method is ideal for cleaning air conditioner coils with large, loose materials on the surface. But, it’s not great for removing small particles or pieces that are especially stuck in place.

Most HVAC professionals will only clean the condenser coil with compressed air, because it’s the coil located outside the home. Cleaning the indoor evaporator coil with compressed air would result in dust and debris getting blown throughout your home.

Cleaning AC coils with commercial cleaners

Commercial cleaners can work on both the evaporator coils and condenser coils. They come in many different forms: everything from foaming solutions to self-rinsing formulas. To clean your outdoor condenser coils with a commercial cleaner, the HVAC professional will turn your unit off and clean off excess debris. Next, they’ll spray the coil with a commercial cleaning solution, let it soak for a few minutes, then rinse it off with warm water.

To clean the evaporator coil, found inside your home, the HVAC professional will turn the unit off, gently clean excess debris by hand, then open up the unit to reach the coil. The technician will then spray a self-rinsing product on the coil and close the unit. Once the unit is turned back on and the cooling process continues, the solution will rinse off on its own and the coil will get clean.

Cleaning AC coils with detergent

While cleaning coils with commercial cleaners is always an option, most AC coils can also be cleaned with the age-old combination of dish detergent and warm water. To do this, an HVAC technician will mix a low-acidity household dish detergent with warm water, then turn the unit off and spray the mixture on each of the coils with a low-pressure sprayer. It’s essential the technician uses a low-pressure sprayer, because something high-pressure, like a power washer, will damage the coils. The technician will wash the coils off with warm water after they soak for a few minutes.

What AC coil maintenance can homeowners do?

Scheduling regular maintenance with a licensed HVAC professional will help keep your AC coils clean and your unit running smoothly. For a homeowner, regular maintenance that does not require a professional includes changing your AC filter every three months, which will help keep dirt, dust, and debris out of your unit and off the AC coils.

Homeowners can also work to keep debris and other unwanted items off the outdoor unit of their system to avoid any extra weight crushing the parts inside, like the condenser coil. Plus, keeping anything growing outside at least 2 feet away from the unit will ensure your coils aren’t interrupted by any roots or plants.

How often should you have your AC coils cleaned?

A licensed HVAC professional will clean your AC coils while performing routine maintenance on your air conditioner. A professional should service your air conditioner twice a year, although once a year is sufficient for certain HVAC systems. While a technician is cleaning your coils, they’ll also perform any coil troubleshooting necessary to determine if your AC coils are causing bigger problems for your unit. If you keep a regular air conditioner maintenance schedule and get your coils cleaned on a consistent basis, your air conditioner should function effectively for many years.