How to Clean AC Coils

The summer heat is hard on an air conditioning system. This year, stop the problems before they start by cleaning your coils and taking other small precautions to set your system up for success and lower your utility bills.

Outdoor A/C unit must withstand all weather.

Should You Cover Your A/C Unit?

Learn the best ways to maintain your A/C unit in the off season.

Photo by: Shutterstock

Shutterstock

While most air conditioner repairs are best left to a professional, there are several things you can do to boost your system’s performance and lower your utility bill. From changing your filters and cleaning your coils to being a little more mindful when landscaping, you can make a big difference with minimal effort. When you search “how to clean AC coils” online, you’ll likely be overwhelmed with the options and industry terms thrown around in the countless tutorials. This is because air conditioning systems are fairly complex machines, with most having both an inside and outside unit that harmoniously work together to cool your home. Both units have coils, so it is important to start by identifying what you will actually be cleaning.

Prep and Clean the Coils

Before we get started, it's important to cut the power to your unit to avoid electric shock to you or damage to the unit. We’re going to focus on your outside unit’s coils. More specifically, we’re going to clean the fins, which run along the outside of the unit. Oftentimes, these fins get dented from years of wear and tear, making it hard for air to pass through them. If you notice that your unit’s fins are dented and bent, buy an AC fin tool at the hardware store and use it to straighten the fins (Image 1). Once you’ve straightened the fins, use a vacuum to remove any debris (Image 2). Now that the surface is clean and any debris within the fins has been cleared, you can use a foaming AC coil cleaner to coat the entire surface of the fins (Image 3). This cleaner will soak into the coil and begin to break free any remaining debris. Our cleaner featured a scrubber on its cap, but you could also use a stiff brush to further clean between the fins (Image 4). Though most of these foaming cleaners are self-rinsing, using a hose to rinse the area will help to wash away dirt and other buildup.

Clean Around Outside Unit

Over time, dirt, mulch and leaves can gather around the base of the outside unit and cake along the sides. Once a year, it's wise to rake back any buildup and clean along the bottom of the unit to keep the fins clean and free of buildup.

Photo by: Kamron Sanders

Kamron Sanders

Change Your Filter

To keep your air conditioner running efficiently, it’s imperative that air can flow through the system. Many times, units begin to run poorly and suffer due to insufficient airflow caused by clogged return filters (Image 1). Returns get their name because they are where the system removes the hot air from the space and returns the cooler air for recirculation. It would be horribly inefficient to constantly cool down the hotter outside air, so the system recycles the already-cooled air in the home, cooling it and passing it through once more. All return covers are different, but they typically have two latches that you pull back by hand, releasing the door (Image 2). To replace the filter, simply measure the return size or reference the old filter’s listed size, buy a new filter and set in place, being sure to follow the air-flow-direction arrow printed on the filter (Image 3). Regularly changing filters according to the manufacturer’s guidance will save you money and keep you cool all summer long.

Next Up

Should I Cover My A/C Unit in the Winter?

Learn the right and wrong way to protect your A/C unit during the off-season.

5 Best Portable Air Conditioners Under $700

Beat the summer heat with a portable AC unit. Check out these top-rated models with features like quiet operation for bedrooms and dehumidifiers for hot, humid spaces.

Swamp-Cooler Maintenance

Check out these cleaning tips for energy-efficient evaporative coolers.

How to Remove an Air Conditioner

Follow these step-by-step instructions and you'll never know it was there.

How Ductless Air Conditioners Work

Thinking of installing a new ductless HVAC unit or switching out your existing system? Get the 411 on all the pros, cons and details to discover if it's the right choice for you.

Furnace Maintenance

Save on utility bills and head off carbon monoxide problems with these tips.

How to Drain a Water Heater

Extend your water heater's life span by draining the tank annually to remove any sediment that may have built up.

How to Protect Wood From Humidity

Fans, proper venting can lower humidity levels and not affect natural materials.

10 Home Maintenance Tips for Spring

A certified home inspector shares 10 home-maintenance tips for spring.

How to Wire a Light Switch

Electricity is a mystery to many people, but some electrical projects — like wiring a switch — are so simple that anyone can do them. With a few easy steps and the right knowledge, there’s no need to hire an electrician.

Our Latest How-Tos

On TV

Follow Us Everywhere

Join the party! Don't miss HGTV in your favorite social media feeds.