How To Clean An Evaporator Coil

How To Clean An Evaporator Coil in Various Ways

Ian Mutuli
Updated on

Like most mechanical devices, an air conditioner requires essential maintenance and cleaning. However, most people forget to pay attention to the components of the system that are air handler enclosure or are out of sight within the system cabinet. The evaporator coil is one of the essential components in your AC unit. With a dirty evaporator coil, your AC system will, in most cases, drop its performance or even break down or damage the whole system. Therefore, before handling the AC coils, you have basic knowledge of how to clean an evaporator coil.

This write-up will provide fundamental information on air conditioner functions and the importance of the evaporator coils. Furthermore, we have instructions on how to clean AC evaporator coils.

Why Do You Need an evaporator coil?

An evaporator coil is a component inside the indoor air handling unit that consumes the heat from the air inside your house. The coil works beside the condenser coil to boost the cooling performance of your air conditioning system. The condenser coils release that captured heat into the air via the outdoor cabinet.  Mostly the AC evaporator coils are usually attached to your furnace or inside your air handler. The coils are typically made of copper and are surrounded by aluminum fins that boost heat transfer.

The evaporator is vitally crucial since they provide the cooling required to produce cold air, especially in the hot seasons. They also play a part in the dehumidification proved by your air conditioners. When the coils cool down, water condenses and is removed from the air inside your room. Then the water is collected in a drain pan and flows away safely.

The performance of the ac evaporator coils goes down whenever the coils get dirt. Remember, the air that flows across the coil will have dirt, pollen and other impurities, which will stick and cause dirt on the coils.

That being said, you should check your evaporator coils regularly and clean them when need be. For the coils that are prone to collecting dirt or debris efficiently, they should be cleaned monthly. However, the typical system should be cleaned every three months before the cooling season starts and at least annually during your annual scheduled HVAC maintenance.


How to Clean an Evaporator Coil

The first important step before you start cleaning your air conditioner coils is getting access to them. As we mentioned earlier, the evaporator coils are found inside the indoor unit at the back of the removable access panel.

Before you launch into the cleaning process, you must switch off the air conditioner at the thermostat. It is again noteworthy that you switch off the thermostat an hour before you start cleaning when you have done that, you will remove the access panel on the air filters to show the coil.

Then you will use one of the following methods to get your unit's evaporator coils cleaned:

1. Cleaning AC Evaporator Coils Using Compressed Air

The use of compressed air is usually more straightforward. However, you must wear protective gear, especially for your eyes. Primarily the compressed air method is used for light accumulations of dirt and other impurities.

To get your job done thoroughly, you should aim the high-pressure air across the dirty coils opposite the normal airflow. You start with the cleaner to the dirtier side though you should maintain a consistent airflow across your evaporator and condensing coil. You can then place the nozzle debris to remove the stubborn dirt or debris. To prevent the fins from getting damaged, you must direct the air pressure directly across the coil fins.

2. Cleaning AC Evaporator Coils Using a Brush

The other effective technique of getting rid of light accumulations of dirt from evaporator coils and condenser coils. This method will allow you to have more control over the area you are cleaning and the pressure you require. In addition, these brush cleaning methods will prevent you from using chemicals or liquids.

With this technique, you will only require to use the brush directly on the evaporator or compressor coils and sweep the dirt away. You could also use the brush to scrub the more stubborn dirt. It is important to note that you should use a softer brush to clean the fins.

3. Cleaning AC Evaporator Coils Using Commercial Cleaners

When it comes to this option, you will have a couple of options you could use to clean ac evaporator coils. So you will need to select a brand of cleaners that you like the most. Then you need to follow the instructions as directed on the product you get.

Most of the cleaners are the foaming kind that will clean the unit's drainage system thoroughly. You will mainly require spraying the cleaner on the evaporator and condenser coils and allowing the foam to drain away from the dirt if need be, repeat the process for more stubborn debris.

4. Cleaning AC Coils Using Mild Detergents and Water

This is a perfect cleaning method if you don't want t use a commercial cleaner. For cleaning evaporator coils with the detergent and water method, you will need to make a mixture of your mild detergent and warm water. Then spray the mixture using a garden sprayer or spray bottle on the evaporator and compressor coil and let it soak for a while.  Then you will use a clean loose material or brush to wipe the solution. If needed, you could repeat the process to remove the stubborn dirt.

5. Heavy-Duty Cleaning

Heavy-duty cleaning is the technique you use if your air conditioning system is heavily soiled. This method requires strong cleaning chemicals and equipment like a pressure washer or a steam cleaner. This method is complex and may require the removal or replacing of the system components or reattachment or cutting of the refrigerant lines, and the reassembling of the whole system afterward. Therefore, this technique may require you to book an appointment with your professional HVAC contractor for your home or business cooling system.


Signs That You Need to Clean Your Evaporator Coil

Split-system cooling systems like the central air conditioners consist of indoor and outdoor units. The indoor units have the evaporator coils and the air handling system, while the outdoor unit contains the condenser coils and compressor. The evaporator and the condenser coil is critical unit that should be adequately maintained and cleaned regularly. To know if your evaporator needs cleaning, you can tell by seeing the following signs.

1. Air Conditioning Loses Cooling Capacity

When your air filters start to lose their cooling function, you should know something is a miss. Basically, dirt and debris will reduce the efficiency by negatively impacting the air blowing process, reducing the heat transfer process. If you notice that your air filter's cooling function is slower, the coils need to be cleaned.

2. Air Conditioning Runs Longer

If your air conditioner function starts to run for more extended periods, then your indoor and outdoor unit might be dirty. This means that your air filter will even consume higher energy than regular times. Then you will need to clean the dirty evaporator coils. A clean evaporator coil will use 40 % less energy than an air conditioner with dirty coils.

3. Coil Develops Frost During Operation

When you notice that your ductwork system has frozen during an operation, there might be an issue with your air filter unit. Dirt and debris can significantly affect the cooling system function and even cause a breakdown of the system. So if you observe that your air filter keeps stopping, you must clean the evaporator or the condenser coils.


Frequently Asked Questions (FAQ) on How to Clean an Evaporator Coil

1. How Often Should You Clean AC Evaporator Coils?

The Ac coils are cleaned when they are dirty. How often the coils become dirty will depend on how often you use your air conditioner, how often you change the filters and the dirt or debris amount in your home. Regardless, you must have the whole ductwork system checked by an HVAC professional at least once a year. Remember, with clean coils, and you are guaranteed improved indoor air quality in your living space.

2. Does an indoor air-handling unit come with evaporator coils?

An air handler unit is usually installed indoors and works with outdoor air conditioners to provide cool air. For the unit to provide adequate air conditioning, it comes with two main components: evaporator coils and condenser coils.

3. Where is the air intake side on an air conditioner?

Usually, the indoor part of your unit has an air conditioner return intake that is located mainly on the ceiling. The return intake grille will include a filter that helps keep the dust and debris away but still allows cool and fresh air.

Ian Mutuli

About the author

Ian Mutuli

Founder and Managing Editor of Archute. He is also a graduate architect from The University of Nairobi, Kenya.