How to Clean Air Conditioner Coils Properly To Keep Them Running Forever

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Nothing is as relaxing as entering a cool, comfortable house on a warm, humid summer day.

Thankfully, we’ve been enjoying air conditioning for over 100 years since Willis Carrier invented it in 1902.

For most people, imagining life without air conditioning is hard to do. But failure is the destiny of every AC unit in time.

To avoid days or weeks of hot sticky weather inside, your AC system needs regular maintenance and cleaning. 

It is especially important to clean your air conditioner coils regularly.  Doing so will improve its efficiency, save you money, and extend the system’s lifespan.

This brief how-to guide will discuss the ins and outs of cleaning your AC coils yourself.

If you have any questions or comments, please drop them below in our comments section.

Types of coils in an air conditioner unit

Split system central air conditioners have two components: an indoor component (usually a furnace and fan coil) and an outdoor component (generally referred to as the air conditioner).

Each unit contains an evaporator coil essential to the air conditioning system.

The evaporator coil is usually located on the outlet side of a furnace or the air intake (fan) side of a fan coil. Its job is to remove heat from the indoor air, allowing the blower fan to return cool, fresh air into the home.

Condensing coils

clean air conditioner coils

The condenser coil in the outer unit allows heat to escape from the system. Most condenser and evap­orator coils are made of metal tubing, which works through thin aluminum strips called fins.

With different coil designs and compositions, for example, all-aluminum coils, or backbone fin coils, airflow through the coil helps transfer heat energy from inside the house into and out of the coil.

Since the coils play an essential role in the process, cleaning them regularly helps keep your ac system healthy. It may seem like a good idea to clean your coils yourself, but the best and easiest way is to have a technician clean them for you.

Your local Carrier® HVAC dealer will know what’s required to maintain your air conditioner for optimum efficiency and longevity, and they’ll be well trained.

Why Is It Essential to Clean AC Coils?

Because of the surface dampness from the cooling process, close proximity between the coil fins, and the amount of air that flows across them, dust, debris, and other contaminants can form on the coil surface.

Over time, this buildup reduces the system’s ability to move heat into and out of your home, thus reducing its ability to cool your home.

If dirt accumulates on the coil, it could impede or block the airflow that’s so important to an entire process. This can result in having a less pleasant home, increased electricity bills, and decreased energy efficiency.

Dirty coils make the machines work harder than they were designed to work, resulting in shorter machine life and possibly expensive repair costs. The cleaner the coils are, the more efficiently the air conditioner will work.

Dirty coils can lead to:

Increased operating temperatures

clean air conditioner coils

If the excess formation of debris and dirt causes strain on the compressor and fan motors, they will work harder and at increased temperatures to achieve the desired indoor comfort.

Less comfort

Your air conditioning system helps eliminate unpleasant and unwanted humidity as a component of the cooling procedure. Dirty coils can cause an increase in moisture inside the mattress and decrease overall comfort.

Reduced cooling efficiency

The buildup that accumu­lates on the coil’s surface causes it to work harder to absorb and release heat, which leads to less efficient operation.

Reduced cooling costs

Lower efficiency means higher running costs. Dirty coils involve spending the extra money to maintain your space cooler.

Increased System Wear

A blocked evaporator may cause the compressor to run at high temperatures, which stresses the entire system, including the compressor itself. Since the compressor is among the most expensive replacement parts inside the air conditioning system, protecting it can save you from high repair bills.

System repairs or replacement

Overly stressed components can cause system breakdowns, leading to service calls, replacing system parts, and replacing an entire system in more extreme situations.

How Often Should AC Coils Be Cleaned?

clean air conditioner coils

Cleaning AC coils must be done regularly.

However, how quickly they get dirty depends on how often you use your air conditioners, whether you have filters, how many times you clean your filters, the quantity of debris in the air both inside and outside your house, and the number of people who live there.

We recommend having an HVAC technician perform a maintenance check on the air conditioning unit once a year before the hot summer months. They can properly clean out the coils, change the filters, and test the system to ensure everything is working properly when you want it most during the summer.

How to Clean AC Coils

Because air conditioner coil replacement is essential for your comfort and efficiency, getting the job done right is crucial.

Because of the delicate structure of the coils that help the heat transfer, ensuring they don’t get damaged when cleaning is also very important.

That is why we suggest hiring a professional. Using a trained Carrier® specialist, your air conditioner will be the most reliable way to guarantee its efficiency and durability. They are not only adequately trained to clean your AC coils, but they can also test your system before the heating season to ensure your unit is working at its peak.

However, knowing the different methods and processes involved with AC coil cleaning can help you understand what to expect and communicate your concerns with your HVAC dealer.

Getting to the coils

clean air conditioner coils

An air conditioning system has an outdoor condensing coil (or compressor) and an indoor evaporator coil.

Your evaporator coil is usually located inside your furnace and has a cabinet or is housed inside an air handler or fan coil unit.

Each model is slightly different, but your Carrier dealership can usually get into the condenser coil via an access panel often removed with a nut driver or screwdriver.

The condenser coil located at the outside unit usually surrounds the inside components and primarily serves as the outdoor unit’s side walls. It’s either well exposed and protected by a sturdy metal wire coil guard or not so visible and protected by a more decorative metal outside panel.

Sometimes, the top layer of the skin might need to be removed. After the coils are accessible and visible, your dealer will inspect the coils and determine the correct cleaning methods following the manufacturer’s recommendations. This might include straightening bent fins with a particular fin-straightening device.

Ways Of Air Cleaning Conditioner Coil 

Compressed Air

Your dealer may use any combination of shop vacs, compressed air, and cleaning chemicals that match your air conditioning unit model specifications.

This method is usually suggested for the outer condenser coil. Cleaning the inner evaporator coil using compressed air will blow debris into the home.

Compressed air can be an efficient, quick, and inexpensive way to remove surface dust, dirt, and debris from the coil. If you want to clean an outside coil using compressed air, an HVAC technician will blow the air into the coil from the opposite side of where the air normally flows.

This will cause air to push through the front side back through the back side. Your tech will blow the air straight into the fins, not at a slight angle. Because the fins are extremely thin, they’re easy to bend.

The service technician may use the shop vacuum to clean the dirt and debris off the coil. These activities will remove loose surface materials from the coils. If you need to remove stubborn buildup, your mechanic can use a commercial coil or a household detergents cleaning solution.

Household Detergent

clean air conditioner coils

There are several coil cleaning solutions available for use on air conditioner coils. However, they can also be cleaned using water and mild household detergents.

The water and detergents mixture is applied to the coils using a sprayer. The coils are then lightly rinsed using a garden hose or gently allowed to drain naturally. You can repeat this process as often as needed.

If a contractor uses this method, ensure they use a low-pressure nozzle, not a pressure nozzle. In addition, they should never use a pressure washer because the high-pressure spray could damage the coil’s thin steel fins.

They may reduce heat transfer capacities and restrict airflow if you see bent or damaged fins. Also, be sure they aren’t using a highly acidic detergent. The aluminum and alloy metal used in the coil are easily damaged by cleaners and cause corrosion that will shorten the coil’s lifespan.

Commercial Cleaners

Your car dealership may offer to clean your air conditioning (AC) coils with commercial coil cleaning products. Many different types are available, including cleaners for evaporator and condenser coils.

They may be found in aerosols or available in bulk for sale. When cleaning your outer coils, the contractor will remove any surface debris by hand or using a fine brush. They will proceed by cleaning the coil using the recommended cleaner and rinsing it with water according to the manufacturer’s instructions.

To clean your inside condenser coil, the builder will usually clear larger debris by hand, then use a particular brush to apply a self-rinsed condenser oil solution. This product will clean the coil after it has been switched on during the cooling process.

A/C Coil Cleaning Methods

There are many ways to clean your air conditioner coils, and each one will be effective. The evaporator and the condenser coils will have a different cleaning method.

Cleaning Condenser Coils

To clean the condenser, the initial step is a visual inspection of its condition. Next, you’ll want to look for vegetation growth around the pads and remove any weeds, grass, or growth that could block the coils. On the condenser, you may wish to remove any debris from the fins or louvers, such as grass, leaves, etc.

If the device is turned on, you’ll want to turn it off, so the debris doesn’t get sucked into the coils. You can use a broom or brush to sweep away the larger debris. Since the fins may bend, you don’t need to brush too hard or force inwards towards the coils.

After removing the bigger debris, use a fin comb or toothbrush to straighten any bent or damaged fins and clean any dirt or water debris between the coils inside the condenser. Next, disconnect the power block from the device.

Next, lift out the fan shroud and remove it from the case. Be careful not to pull too strongly on the attached wires.

Spray the coils from inside out using a hose with a pressure nozzle attachment. You don’t even have to spray the coils outside since this will only cover the compressor, which could then overheat.

The coils will be cleaned after they’ve been used for a certain period. Next, clean out the condenser unit and replace the fan shroud.

Finally, restoring power to the device involves restoring the power disconnect block.

Cleaning Evaporator Coils

Cleaning your coils is a similar procedure. The first thing to do is turn off the evaporator. You can turn the air conditioning system off, but it’s also recommended to turn off all the breakers that control it in the home’s breaker box. Next, open the evaporator access panel.

Once you gain access, the hard part will be working over the head. The coils can be found on the back side of the device and will be in the position that was most difficult to reach. Again, you need to take care when standing on a ladder so you don’t fall off.

If you’re using a gloved hand to remove the debris buildup, which feels wet and sticky, you can use a fin comb to brush away the debris gently. Be careful not to tear the fin, and don’t let the comb snag on the fins. If you’re having trouble adjusting any bent fins, this may help.

You will need to use a chemical coil cleaner. Foam and set into eliminating dirt, gunk, and buildup. Follow the guidelines for applying and set a time. It’s recommended to wear safety goggles when cleaning the coil.

While the cleaner works away, clean the drip pan where the condensation collects. You may use a scraper or spoon to dig up the muddy residue from the bottom of the pot. However, you want to locate and remove the drain line before scraping begins.

The drain line is the pipe that comes out at the bottom or side of the drain pan’s lower end. You may wish to scrape away from this field. However, if you scrub too hard, you risk forcing debris down the drain line, which could lead to a clog.

Rinsing the Evaporator Coils is Important

After cleaning the drip, use water to clean the coils. Since you’ll be spraying directly onto the coil, you won’t need to use a pressure sprayer. For example, using pressure to spray from outside, the condenser coils can lead to deeper clogs.

Rinse the coils clean, and the debris accumulates into the drip tray and drain pipe. Next, flush the drain line by running hot water through the drip trays for around 10 minutes.

If your evaporator unit is placed above your bathtub, the drain will connect to the tub drain. Before flushing, remove the drain stopper and bracket. This will make the water drain out of the tub. When the drain is clear, you’ll know it because there won’t be any debris in the rinse water.

If you remove everything from the tub drain and evaporator access panel and connect power to the AC again, check that there are no leaks or strange noises and that the air blows cold and hard from the vents.

Heavy Duty Coil Cleaning

If you find that the fin combs or the coil cleaner aren’t penetrating the buildup, you might want to call in an HVAC specialist. They will have the right tools, methods, and abilities to run a deep clean of your coils.

If you find it difficult to access the evaporator or, for any other reasons, cannot perform the job by yourself.

We estimate that professional cleaning condensers and evaporators will cost between $100 and $500.

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