A whole-house AC system can be the difference between a miserable, sweaty summer and a delightful season that you look forward to all year long. But getting a central AC is just half the battle. Once you have it, you must maintain it to continue reaping the benefits and avoid driving up your electric bill or burning out your unit.
One of the most important parts of this maintenance process is cleaning your interior and exterior AC coils. While this sounds like an intimidating chore, it doesn’t have to be. At least, as long as you have the right cleaner at your disposal.
Below, we’ll give you our recommendations for the top 6 best cleaners for AC coils. Our picks include some products specifically designed for mess-free evaporative coil cleaning, some extra-strong formulas for condenser coil cleaning, and specialty products that can take on both jobs.
Disclosure: We may receive commissions when you click our links and make purchases. This does not impact our reviews and comparisons. All opinions are our own. We pride ourselves on keeping our articles fair and balanced. For more info see our disclosure statement.
Our Top Pick: Nu-Calgon Tri-Pow’r HD 4371-88 Cleaner
Nu-Calgon Tri-Pow’r is a highly effective, biodegradable cleaner that is safe for use on nearly all metal components of your AC unit. This unique alkaline emulsifier pulls grease and grime off your coils and suspends them in the solution so all debris can be easily rinsed away using a hose or the natural condensate produced by the unit.
Corrosion inhibitors and biodegradable makeup mean this cleaner is safe for your coils and for the environment. Available in spray and concentrate form, this cleaner is perfect for novice homeowners and professional AC cleaners alike.
Air Conditioner Coil Cleaner Comparison Table
|Product||Details||Where to Buy|
Type: Spray-on alkaline emulsifier
|Check Price Now|
Type: Spray-on neutral detergent
|Check Price Now|
Type: Foam-up neutral detergent
|Check Price Now|
Nu-Calgon 4171-75 Evap Foam No Rinse Evaporator Coil Cleaner
Type: Foam-up alkaline emulsifier
|Check Price Now|
Type: Foam-up neutral detergent
|Check Price Now|
ComStar Coil King, External Condenser Coil Cleaner and Brightener
Type: Spray-on alkaline cleaner
|Check Price Now|
What We Look For in a coil cleaner
Finding the right cleaning product for your AC can be a challenge given the vast selection of choices available. Not only are there dozens of brands to choose from, but all seem to come in different forms. From foaming sprays to concentrates, from acid to alkaline, there are a lot of considerations that you need to consider when finding the best AC coil cleaner for your needs.
When looking for the top six best choices, we paid special attention to all these different features and how each contributed to the product’s ease of use, effectiveness, and the safety of your AC unit.
Related Article: What is an HVAC System and How Does it Work?
Ease of Use
AC coil cleaners are available in two main application forms: foam and spray. Foam cleaners tend to be easier to use and require the least amount of work on your part. But spray cleaners can be the better option in some situations.
Foam cleaners are made to spray on as a liquid and then foam up to help dislodge debris and grime from the surface of the coils. The best foam cleaners have a delayed foaming action. This allows the liquid to drip into hard-to-reach areas and better penetrate the coil system before the cleaning action of the foam begins.
Foaming cleaners are very easy to use because they don’t require any scrubbing. However, they tend to be less environmentally friendly and aren’t always appropriate for copper coils.
Spray cleaners are available in ready-use spray bottles and concentrates that you can mix with water and apply via a low-pressure power sprayer. Some cleaning action will be accomplished via surface contact, but most of these products require scrubbing or brushing for the best results.
For layered or hard-packed grime, spray cleaners may be more effective than foam cleaners. These heavier cleaners are more likely to penetrate through that build-up. These cleaners are also more likely to penetrate into crevices and other hard-to-reach places due to their natural tendency to drip and run along the coils.
How Well it Works
How well a coil cleaning product works, or more specifically, what type of grime it works well on, depends on the chemical makeup of the solution. In general, there are three options in this department: acid, alkaline, and neutral. Each type functions a little differently, is best suited for specific types of build-up, and requires different considerations during use.
Acid AC coil cleaners typically have a pH between 0 and 1. Their highly acidic nature makes these cleaners especially effective against mineral deposits, rust, and other build-up related to metal wear.
Of course, acid is known to be highly corrosive, which means these products can eat away at your metal coils if misused. They are especially corrosive to copper.
The acidic nature of these cleaners may also prevent them from being used outdoors due to the potential to harm plants or acidify the soil around the unit. Many acidic products are only rated to be used on indoor evaporators and not outdoor condensers.
Alkaline cleaners sit on the other end of the spectrum from acid cleaners and typically have a pH between 13 and 14. The highly basic makeup of these cleaners means they are especially good at breaking down oils and grease.
While not as well known for their corrosive nature, highly alkaline solutions can be just as dangerous to metal as acidic solutions. But, many alkaline cleaners are made with corrosion inhibitors that counteract this destructive process and make them safer to use on all types of metal.
Neutral Detergent Cleaners
Neutral coil cleaners are generally slightly basic, with a pH of around 8. Instead of relying on a very acidic or alkaline activity to break down grime, these cleaners contain detergent. Like other household detergents, these products clean by emulsifying grease and oils in the cleaning solution.
How effective these products vary from brand to brand, but one thing they all have in common is they are safer to use outdoors. Because they have a nearly neutral pH, they are much less likely to harm the surrounding environment, making them a great choice for outdoor condenser coil cleaning.
Potential to Damage Coils
Neutral, acid, and alkaline cleaners are all available in self-rinse and rinse style formulas. While it may seem like self-rinse options would be less likely to damage your coils than the alternative, the truth isn’t that straightforward. In fact, both types can cause issues if not used properly or if certain conditions aren’t met.
Because these “conditions” aren’t always spelled out in the instructions, it is important to understand the differences between self-rinse and rinse solutions to assure you find the best option for your needs.
Both foaming cleaners and spray cleaners are available in self-rinse solutions. These products are meant to be left on your coils after cleaning and are washed away as condensate gathers on your coils during AC use.
These products are straightforward to use, especially on indoor evaporators. On the negative side, the “self-rinse” function only works if your AC is on and the humidity is high enough to create condensate. If these factors aren’t met, the cleaner could stay in contact with the metal coils long enough to erode and damage them.
Note: Most self-rinse solutions contain corrosion inhibitors that make them less likely to damage the metal. But, even these products need to be used with caution, especially if cleaning when the AC is not in use or in arid environments.
Cleaners that are not self-rinsing need to be manually rinsed off the coils after use. This, as you can imagine, can be a messy process. Most products that require rinsing are meant to be used outdoors on condenser coils. In this case, rinsing is fairly easy and won’t require any extra cleanup.
On the plus side, manually rinsing products off after use assures no future damage to your coils. So, while these cleaners typically aren’t as easy to use, they do tend to be the safer option for your AC.
In the end, all types of AC cleaners have their benefits and drawbacks. When choosing the top AC coil cleaners, we looked for those products whose benefits most outweighed their drawbacks.
Learn More: Air conditioning problems? Here’s how to fix them.
How to Clean Your AC Coils
The exact steps you should follow when cleaning your AC coils depend on the type of cleaner you’re using and whether you’re cleaning an indoor evaporator or outdoor condenser. But, in general, the cleaning process will look something like this:
- Locate your coils. Depending on which coils you are cleaning, you’ll either need to remove the panels on your exterior AC unit or locate the evaporator indoors, usually near your furnace or central venting system. Turn your AC off and follow the instructions in your manual to remove the outer panels or walls to expose the inner coils.
- Remove any large debris with a brush. Spider webs, leaves, dirt, and other debris is likely to have collected in your outdoor unit. Even indoor coils can accumulate a surprising amount of lint and cobwebs. Use a dry coil brush and shop vacuum to remove this debris from the inside of the unit. If needed, use condensed air or an air compressor to blow debris loose.
- Apply your coil cleaner. Be sure to read the cautionary label on your cleaner options before choosing one to use. Some are only safe for aluminum coils, while others can work on aluminum and copper. Follow the directions on your cleaning product to apply the solution to the coils. Be sure to follow safety recommendations and use protective eyewear and gloves.
- Scrub as directed. If using a spray solution, you’ll likely need to use a brush to clean the coils. Foaming cleaners don’t require scrubbing, but it can help, especially if the coils are very dirty.
- Rinse as directed. If the cleaner instructs you to rinse it off after use, you should do so in a timely manner. For outdoor units, this is as simple as using a garden hose to rinse every coil. Most evaporator cleaners are self-rinsing. In the case of a self-rinsing agent, be sure to turn your AC on and allow it to run all day. This will create the condensate necessary to remove the cleaner from the coils.
Note: You should clean your AC coils once per year. However, a second round of cleaning may be necessary if you experience a lot of blowing pollen, cotton, wind, wildfire ash, or other particulates in your yard.
For best results, clean your AC in the spring. By starting the hot season with clean coils, you’ll ensure your unit is working as efficiently as possible.
Alternative HVAC AC Coil Cleaners from Around The Home
If you don’t have a commercial cleaner on hand or are looking to avoid chemical cleaners, there are a few easy DIY alternatives worth trying.
You can loosen and rinse away much of the debris on your AC coil by just using water. When going this route, you should use a coil brush and vacuum to remove large debris first.
For outdoor coils, your best bet is to use a garden hose with a power sprayer end. The concentrated spray will help direct debris down and away from the unit, but you should keep the pressure to a minimum to avoid damaging the components.
For indoor coils, you can still use water if you don’t mind a little cleanup. Use a spray bottle and towels to rinse the coils and prevent water pooling in your utility room.
Mild Soap and Water
If your coils are dirtier than what water alone can rinse away, you can use mild dish soap. Add a few drops to a spray bottle or bucket filled with distilled water. Apply this gentle wash by spraying it on or with a coil brush. Scrub as needed, and then rinse away with a hose or clean spray bottle.
Vinegar and Water
If there is a lot of mineral build-up on your coils, then a vinegar and water solution is going to be more effective than a detergent solution. Combine equal parts of water and vinegar in a spray bottle or bucket, apply to the coils, and scrub.
Be sure to rinse thoroughly, especially for copper coils.
The Best Cleaners for AC Coils
For dirty AC coils, your best bet is to pick up a commercial product specially formulated to cut through layers of build-up. Here are our six favorite products worth considering.
Nu-Calgon Tri-Pow’r cleaner is a great choice for anyone looking to clean their entire AC system using just one product.
This unique alkaline emulsifier is tough on grease and oil buildup but safe to use on aluminum and copper coils. The key is in the addition of corrosion inhibitors which prevent damage to metal components when used as directed.
Tri-Pow’r is safe to use outdoors and 100% biodegradable. For indoor use, it is self-rinsing so long as the AC unit is on and producing condensate.
Best of all, this all-around useful cleaner comes in a variety of packaging options from ready-to-use spray to super concentrate. For those not interested in buying a dozen products just to clean one AC unit, this is the cleaner you want. It is safe to use on evaporators, condensers, permanent filters, fan blades, and motors.
ComStar Coil Safe is a non-toxic, biodegradable cleaner made for those with concerns about using chemicals in their home and yard.
This pH-neutral cleaning agent uses gentle detergents to emulsify and capture grease so that it can easily be flushed away. It helps clean and brighten copper and aluminum components without the risk of metal fatigue or damage.
Coil Safe is made specifically for use with indoor evaporators. However, given its environmentally-friendly formula, there’s no reason you couldn’t use this on outdoor condensers. It is self-rinsing and comes in a concentrate that gives you more in a smaller package.
This cleaner should be diluted for use. For tough build-up, dilute with three parts water. For more routine cleaning, it can be diluted with up to ten parts water.
Frost King ACF19 Foam Coil Cleaner
- Foaming, no-scrub cleaning action
- Neutral, non-corrosive
- Can be used on other household appliances
- Easy-use aerosol sprayer
Frost King Foam Coil Cleaner takes the cake for the easiest cleaner to use.
This foam cleaner sprays on wet to get into every crack and crevice, then expands to lift dirt, grease, and debris away from your coils. The self-rinse formula can be left on to be washed away by the natural action of your evaporator or condenser.
The aerosol spray can is not as environmentally friendly as the options listed above, but it is CFC–free and free from chlorinated and fluorinated solvents. Plus, the pressurized can allows the spray to come out whether you’re holding the can upright, sideways, or upside down. This makes it easy to get to all the components in just one pass.
In addition to AC coils, it also cleans lawnmower engines, radiators, and refrigerator coils. It also acts as a deodorizer thanks to the pleasant lemon scent. If you’re looking for a cleaner that’s both versatile and easy to use, Frost King has you covered.
If you want the cleaning power of our top choice coil cleaner but in an easier to use package, then Nu-Calgon’s Evap Foam Cleaner is the way to go.
This alkaline emulsifier is nearly as powerful on dirt and grease as Nu-Calgon’s Tri-Pow’r cleaner but comes in an aerosolized canister that makes applying it a breeze. The liquid cleaner sprays even when the can is upside down and quickly foams up to capture debris to leave the surface shining.
Evap Foam Cleaner is safe for use on evaporators and condensers of any type. You can also use it to clean other household appliances. This Nu-Calgon product is not as environmentally friendly as our top choice and isn’t biodegradable. But it is safe for use in food processing areas.
With corrosion inhibitors, this cleaner is safe for use on aluminum and copper. It can be left on longer than many foaming products and will self-rinse as your AC operates.
Lubegard Kool-It Foam Cleaner is specially made to clean and deodorize the AC system in cars, but it also works impressively well as an AC coil cleaner.
Like other foam cleaners featured here, this sprayer makes it easy to apply the detergent over your coils. As the liquid seeps into cracks and crevices, it begins to expand, taking dirt, residue, and grease with it. This formula is especially effective at reducing odors and destroying mildew and mold.
After a few minutes, the foam begins to break down, turning back into a liquid and dripping into the water catch, providing further deodorizing action.
This neutral cleaner will not corrode metal and can be used on both aluminum and copper coils safely. The deodorizing effects of the cleaner can last for up to six months.
ComStar Coil Cleaner and Brightener was made specifically to take on the tough grime that collects on outdoor condenser coils.
This unique spray-on solution features some foaming action that aids in the cleaning process. The instructions still recommend using a coil brush to scrub the surfaces, but you’ll notice much of the grease and dirt begins to wash away before scrubbing begins.
It is not well suited for indoor use because the solution requires a manual rinse. But, thanks to the gentler alkaline makeup and addition of corrosion inhibitors, it is safe for use on copper and aluminum condensers.
Like the first ComStar product we featured, this cleaning agent is biodegradable and safe for use in the yard. However, it is much more caustic than Coil Safe and thus must be handled with care, especially in the concentrated form.
The Best AC Cleaner to Get the Job Done
When it comes to keeping your AC working as efficiently as possible, it’s all about keeping those coils clean.
For a wonderful all-around AC cleaner, we recommend Nu-Calgon Tri-Pow’r. This spray-on alkaline emulsifier is powerful on dirt, grease, and residue but safe for use on all components of your AC system.
If what you’re after is a cleaner that will make the job as easy as possible for you, then Frost King Foam Coil Cleaner is the one you want. This highly effective neutral detergent foams up to lift debris away from your coils without scrubbing and self-rinses, so you hardly have to lift a finger.