How to Clean AC Coils by Sweet Home Tools

Published by John Martin on

How to Clean AC Coils

Summers are on the way, and one should get ready for heat by servicing the AC inside the house. Cleaning the coil of AC is essential for its performance. It can trap lots of dust, pollens, microorganism, and other pollutants while working. So your AC’s performance can get affected. It can slow down and fail to work with its maximum potential. So cleaning it becomes essential at least once or twice a year.

You don’t have to pay the high bills of electricians for such a simple task as cleaning the AC coils when you can do it yourself without much hassle.

In this article, we will discuss why cleaning the AC unit coils is essential and also How to clean the AC unit coils without any professional help. Let’s see how these coils work to understand why it is important to clean them occasionally.

How Does AC Unit Coil Work and What is Their Purpose

AC coils play a significant role in the Unit. These coils are used for different purposes, and that’s why they need to keep clean.

Two types of Coils are used in Air Conditioners. These are:

  • Evaporative Coils
  • Condenser Coils

Both these coils work for the same purpose that is to dissipate the heat. But their roles are different as they work in both the front and back section of the Unit.

Evaporative Coils are present in the indoor Unit. These coils in the Air condition traps hot air from your room. The air trapped by these coils is sent to the condenser coils. These coils are in the outdoor Unit of AC. They are released from the Unit as hot air, so the heat is dissipated from the AC as well.

Beside trapping the heated air from the room, evaporated coils also lowers the humidity level of room that speed up the cooling process.

The condenser coils work with motor and special valves that work together to throw the warm air out of the Unit. So the process is interlinked, and both systems work to keep the atmosphere of your room comfortable.

How The Evaporative and Condenser Coils Work

It’s an interconnected system as we said to maintain a cool and comfortable system in your room.

The evaporative coils trap the hot air in the room. The Unit uses cooling gas that traps heat from the air and condenses it in liquid form that is flowed out of the drain later.

The heat that is trapped by the evaporative coils is compressed and made into the hot liquid. It reaches the condenser coils that work with a fan motor. The condenser coils release the heat through the aluminium fins as hot air.

So when we look at the process of how the Air conditioner works, we see how these two coils especially the condenser coils can become dirty due to many outer elements like weather, wind, dust, soot and all other sorts of pollutants. These coils may not perform well due to this buildup and slow down your system.

When your AC slows down in the midseason or fails to perform like it used to be then the most probably it needs cleaning.

Both evaporative coil and condenser coil may trap the dust, pollens, soot or other pollutants from the air of the room. These coils are wet due to liquefying the heat through the compressor. So the dust or other pollutants can stick on or around these coils. The dust may build up over time and reach the point where it can hinder in the performance of these coils. It may result in slowing down your Unit or not being able to work properly.

Problems Dirty Coils May Cause

Dirty coils can cause many problems like

Slows down The AC

These coils play an important role in the function of the air conditioner. Due to dirt and dust, they may not perform well. So it slows down your complete system and affects its performance.

Reduce Heat transfer

As the coils are trapped with dust and pollens, they fail to not only trap heat from the room effectively. So that means less heat transfer to the condenser coils and then less heat transfer out of these coils from the outer Unit.

Increase temperature in the Unit

The heat trapped in the Unit can seriously affect the performance of your Unit. The condenser unit fails to dissipate the heat outside, and that results in increased temperature in the Unit that prevents it from working.

Reduce Life Span of your Unit

The dirt and dust buildup eventually reduce the life expectancy of your Unit. It restricts the process of trapping air and dissipating heat. The heat trapped inside the Unit minimises the life expectancy of your Unit.

Build UP ice on Coils

As the condenser is constantly compressing and solidifying the heat and cooling the system but the trapped dust won’t allow the cooling to get out of the system. It may result in solidifying the liquid as ice which can also gather up on coils further impairing its function.

Reduce Comfort

As the system cannot perform well, it fails to maintain an optimal cool atmosphere in the room. So you may feel a less comfortable experience due to less cooling.

Increase in Electricity consumption

The system is working but not performing well. That may result in more consumption of electricity. So you may notice a spike in your electricity bills.

How To Clean the AC coils

Here is detail instruction of how to clean AC coils. First, let’s see how to clean the Evaporative coils.

How to Clean Evaporative and Condenser Coils

Evaporative coils are located inside the indoor Unit of AC. For accessing the evaporative coils, turn off the AC. You need to consult your AC manual to see where exactly to locate the coils. They should be housed inside a fan coil or near air handle unit.

It’s the condenser coils that are hard to locate. They are present in the outdoor Unit of AC. They are housed inside well protected by the wire coil guard. You need to open the casing to expose the condenser coils. Once the coils are located, they can be inspected to determine if they need cleaning or not. If you see a lot of dirt and dust buildup, then coils need cleaning as well.

Both evaporative and condenser coils are cleaned with different methods depending on how hard the dust buildup is and how badly the AC needs cleaning. It also depends on the instructions recommended by the manufacturers for servicing the AC. Here are some of the ways these coils are cleaned.

Cleaning The AC coils with Compressed air

If you see the dust buildup that can be easily wiped off and it is not sticking to the base, then you can clean the coils using compressed air.


  • Remove the screws or fasteners of the access panel.
  • Place the panel door and screws at a safe place.
  • Light dust or dirt can be removed by directing compressed air on evaporative coils from the opposite direction.
  • For difficult places, place the nozzle near the corners for removing dust.
  • Maintain the airflow towards coil until you see no trace of dirt or dust behind.
  • Avoid the airflow towards the ductwork system to prevent damage.
  • The constant flow will lose even the tough buildup of dust.


  • Use a brush for hard buildups. Make sure the brush is soft and don’t use too much force. Gently brush the coil.

Cleaning the AC coils with Commercial Cleaners

Commercial cleaners are formulated for cleaning the tough buildup. They can loosen up the dirt or mineral buildup on the coils and clean them in less time using fewer efforts.

These cleaners are a powerful agent that removes the hard buildup of dust and dirt from the coils. For cleaning with commercial cleaners follow the instruction given by the manufactures.

  • Spray the cleaner on coils.
  • Allow the cleaner to make foam when it contacts the mineral deposits or scale buildup on coils.
  • You can apply the cleaner again until the coils are properly cleaned.
  • Wipe away the material with soft cloth or wipes.
  • Make sure you clean the solution completely from the coils.
  • Let the coils dry and reassemble the parts again.

Cleaning AC coils with Mild Detergent

Instead of commercial cleaners, you can use mild detergent or water solution for cleaning the coils as well. You can make a solution of detergent and water and spray them on the coils. Use a soft brush to remove the dirt and when it is clean simply clean the area with damp wipes. Cleaning the AC coils with vinegar is also an option if coils have rust or mineral buildup on them.

Final words

Cleaning the AC coils is not very difficult. You can do it at home if you what you are doing and also about the different parts of AC. But if you are not an expert, you can take professional help as well. Many companies offer services. They clean both evaporative coils, condenser coils, filters and service your AC properly. The service of an Air conditioner is important for its long life and good performance.


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