How To Clean An Air Conditioner Coils

The air conditioner coils are among the hidden components within the AC unit. Regular cleaning of these coils is essential to keep your air conditioner functioning efficiently at all times. You might be wondering how to clean these coils, given the complexity of the system. We have consulted the experts in order to give you the right answers.

It can be as simple as your DIY job to the complex and deep cleaning, which are performed by HVAC professionals. Whichever method you choose, here are the steps to clean air conditioner coils:

  • Turn off the power supply and wait until the AC unit has cooled down.
  • Remove the housing case and access panel to expose the coils.
  • Clean the fins and all exposed areas of the coil.

However, different types of air conditioning units call for specific procedures in cleaning. Your cleaning will also depend on the method used and the extent of the debris and dust that have accumulated on the coils. Keep reading as we dive into greater detail and the nature of these air conditioner coils as well as the different ways to clean them.

Worker to cleaning coil cooler of air conditioner by water for clean a dust on the wall in customer home when maintenance service, How To Clean An Air Conditioner Coils

Basic Cleaning Steps

Evaporator coils and condenser coils are among the internal elements of your air conditioner. Here are the steps you need to do to clean the internal parts of your AC unit:

Air Conditioning Repair, Repairman fixing air conditioning system,

Shutdown the Power Supply

As with any appliance or mechanical device, the power supply should be turned off, including the breaker. Then wait until the air conditioner heating system has cooled down. Make this a habit to avert burns and electrocution.

Get Access to the Internal Components

In order to expose the air conditioner coils, the access panel needs to be removed. Loosen the screws and other shafts at the entry panel. In any case, you may need to check on the manufacturer's manual for the specific procedures for the disassembly. Also, wear protective equipment such as an eye shield and gloves.

For an outdoor AC, get access to the interior by removing the fan assembly. Once open, inspect the inner chamber and scoop out dirt and debris. Since these units are exposed to the outdoor elements, the dirt gathered may include dried leaves, dead rodents, and insects.

You may need a vacuum cleaner to remove all the debris. In this step, the only tool you may need is the screwdriver as seen in the photo below.

Installing Air Conditioner Fan Cover

Clean the Fins and All Exposed Areas of the Coil

For indoor AC such as the mini-split models, this step involves removing the air filter, the exterior front panel, the horizontal louver fins, releasing the entire drip pan, and pulling up the blower wheel. Then cover the sensitive electronic parts that may get wet during cleaning with a cloth and seal with curing tape.

Additionally, you need to attach a plastic cover bib and Velcro plastic strips to the AC unit. Then attach a 2-meter hose that serves as an outlet drain that funnels towards a bucket on the floor directly below the AC unit.  Fortunately, these attachments are available in the market and sold as cleaning kits for split air conditioners for your convenience.

Check out this cleaning kit at Amazon.

In the absence of cleaning kits, any DIY waterproof material can serve the same purpose as shown in the photo below. Make sure you attach a hose at the bottom that can funnel the dirt towards a bucket on the floor underneath.

professional worker cleans the indoor unit of the air conditioner

These attachments function as protective shields to limit the mess and drip at the floor while cleaning the coils, thus protecting the flooring and your living space. Also, it protects the wall paint surrounding the AC unit, and lastly, to protect yourself since dust and grime may scatter on air during cleaning.

Once you're done cleaning the AC coils, replace the housing case and access panel. Then it's time to turn your AC unit power back on.

Cleaning Methods

After setting up the preparations of your AC unit prior to cleaning the coils, you can move forward to cleaning the exposed coils. The choice of which method to use depends on the extent of the dirt accumulated on the coils, the type of air conditioner, and also your budget. Below are the different techniques for cleaning air conditioner coils:

Using Compressed Air

If there is not much heavy accumulation of dirt on the evaporator reels, it can be easily removed by blowing compressed air. The airflow should be in the opposite direction of the normal airflow channel through the coils, that is, from the cleaner to the dirtier side.

For heavy dirt areas, position the air nozzle at the bottom side by maintaining a constant airflow across the coils. Avoid blowing the dust and dirt towards the ductwork or the living spaces of your home.

Make sure to wear eye protection while cleaning. Also, a shop vacuum is needed to clean up the dirt and debris as they dissolve. This method is fairly simple and straightforward. You only need an air compressor to aid you in the cleaning.


Using a brush, with liquids or substances, can be an effective technique for removing the minor buildup of dirt from the coils. The advantage of this method is that it provides you with better control by applying pressure over the specific areas to be cleaned, such as the reels and fins. You get the brush directly to the coil and sweep away the dirt.

You can also do heavy scrubbing to remove hard to remove dirt. Due to the sensitive components of the coils, use brushes with soft bristles only. Brushes with hard bristles or wire brushes should be avoided since they can cause damage to the coils. The bristles should be stiff yet smooth enough to remove dirt.  

Check out this air conditioner cleaning brush set on Amazon.

Using Mild Detergent and Water

A mixture of mild soap and warm water can clean the evaporator coils. Hot water and cleanser can be mixed in a spray bottle, garden sprayer, or grip sprayer. Spray on the coils, let the liquid settle to soak, and loosen the dust. With the loosened dirt and debris, you can easily sweep it away with a brush or wipe it with a soft cloth.

Using Commercial Cleaning Agents

Many brands of commercial cleaners are available in the market. They can be in the form of concentrated liquid that requires mixing with water. Mix the solution in a spray bottle for easy application during cleaning. Nowadays, foam spray cleaning agents have become widely used among homeowners and HVAC professionals for their pleasant scent and ease of application.

Check out this product on Amazon.

During cleaning, allow the cleaning agent to settle over the coils for a few minutes to soak and loosen the dirt. After which, you can blow compressed air or simply apply running water with a garden hose to remove the dirt from the coils. Use working gloves as there are strong ingredients that can do harm to the skin.

air conditioner cleaning with spray foam cleaner

Robust or Heavy-Duty Cleaning

The evaporator coils may need robust cleaning when there is a buildup of dust and debris. Strong chemicals and equipment such as a steam cleaner or pressure washer are used for this type of cleaning.

Robust cleaning is more than just a regular cleaning job since it involves disassembling your AC system. It involves removing the coil, cutting and reattaching the refrigerant lines, replacing the vacuum, and refilling the refrigerant.

If the evaporator coils are heavily soiled to significantly affect the cooling function of your air conditioner, it’s time to call a professional HVAC contractor to evaluate the work that needs to be done. They have the training, equipment, and supplies to perform the job.

Robust cleaning of the evaporator coils aims to restore the cooling system function without damage to the reels, fins, and other internal components. Your AC system will get back to its prime condition.

In Closing

Technicians fix air-condition problem at home.

The evaporator and condenser coils are the heart of any air conditioning system. To have your AC unit function efficiently, it needs to be maintained by thorough cleaning on a regular basis, at least once a year depending on how often you use your air conditioner and your location.

Both for indoor and outdoor air conditioners, there are specific steps for cleaning the coils. Shut down the power, gain access to the internal parts to expose the coils, then proceed to clean by using either compressed air, brush, mild detergent, commercial cleaners, or heavy-duty cleaning. The choice of cleaning method depends on the extent of dirt and debris that needs to be cleaned.

If the buildup of dust significantly alters the cooling capacity of your air conditioner, then robust or heavy-duty cleaning needs to be performed by an HVAC professional. It is more than just regular cleaning since it involves disassembling your AC unit with the aim to get it back to its prime condition.

To read more on air conditioning systems and maintenance, check out these posts:

How To Tell If Air Ducts Need Cleaning–10 Signs to Look For

4 Best Air Conditioner Covers For Winter

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