AC Coils (Why You Should Keep them Clean)


Your air conditioning system utilizes two coils in order to cool or heat (heat pumps) your home.

The two coils are an evaporator coil and a condensing coil.

It is essential for your coils to be clean in order for your air conditioning system to function properly.

A dirty coil can cause problems with the airflow (static pressure) and can even cause damage to your compressor.

This guide will cover why it’s important to keep your AC coils clean, how you can keep your coils clean, how to clean your AC coils, and how much it costs to get your AC coils cleaned.

Consider getting your coils professionally cleaned with your local HVAC professional.

Jump to Section

  1. Why clean AC coils are important

  2. How to clean AC coils

  3. How to keep AC coils clean

  4. AC coil cleaning costs

  5. Conclusion

Why Clean AC coils are important

Clean AC coils are critical for your AC system to function properly.

The purpose of your AC coils is to transfer heat from the refrigerant within the coils to the air passing through them.

In this process, the refrigerant either condenses from a gas to a liquid or evaporates from a liquid to a gas.

A dirty evaporator coil restricts the flow of air and prevents this process from happening correctly.

There are a few negative effects that can result from this.

First, your compressor can get damaged. This happens because the refrigerant within the evaporator coil makes its way to the compressor before it is transformed into a gas.

Since liquid cannot be compressed it will cause damage to your compressor, and it’s one of the main reasons a compressor will fail.

Second, a dirty evaporator coil will cause restrictions within your system. This will raise your system's static pressure.

High static pressure will result in your system working harder, which can cause your blower motor to fail faster, and will consume more energy to operate.

Finally, a dirty evaporator coil can cause an AC system to freeze up. Again, this is mainly because of the lack of airflow flowing through the evaporator coil.

A dirty outdoor condenser coil can also cause problems with your HVAC system.

There are three main problems that can arise from dirty condenser coils.

First, your AC system will not cool properly.

Second, your compressor will work harder and less efficiently. This can cause wear and tear on your compressor and will consume more energy.

And third, you risk liquid flooding the compressor, which can cause it to fail.

Let’s walk through why this happens.

The purpose of your condensing coil is to condense the refrigerant from a high-pressure gas to a liquid.

The condensing coil, similar to a radiator in the car, uses airflow to cool the refrigerant.

When the refrigerant is in the condensing coil, it is under high pressure.

The cooler air from outside cools the refrigerant and lowers the total pressure in the condensing coil.

Dirty coils will prevent this from happening properly causing your condensing line to operate under higher pressures.

The result of this high-pressure line is a compressor that needs to work harder to push the refrigeration into the line.

Your compressor that needs to work harder draws more power, causing your system to be less efficient.

And, will break down faster due to it working harder.

Furthermore, your AC won’t cool your home as well as it should.

This is because the refrigerant wasn’t able to cool down enough before it enters the evaporator coil.

When the refrigerant enters the evaporator coil.

It does so through a metering device which reduces the pressure significantly.

If the refrigerant passes through the metering device at too high of pressures, then it will also exit the valve at higher than normal pressures.

Higher refrigerant pressures = higher refrigerant temperatures.

Meaning the evaporator coil will not be as cold as it should be in order to cool your home properly.

Now, your evaporator coil will have a difficult time evaporating all of the refrigerants into a gas.

Which again, can lead to liquid refrigerant entering your compressor.

Since a liquid cannot be compressed, the compressor will get damaged.

Who would’ve thought a dirty condenser coil can cause so many problems?

Below we will cover how to clean and prevent your coils from getting dirty.

However, we always recommend having an HVAC professional clean your coils.

HVAC systems can be complex and you should avoid causing damage to your system.

How to Clean AC coils

We highly recommend consulting with an HVAC professional before attempting to clean your AC coils yourself.

**Both the condenser coil and evaporator coil are located near HIGH VOLTAGE wiring**

Nonetheless here is what the process looks like if you wish to do so yourself.

Your outdoor condensing unit is relatively easier to clean.

First, you need to ensure you disconnect the power from your system.

There is a disconnect plug located near your system, or you can turn off the breaker on the electrical panel of your home.

Next, you want to remove all of the protective panels of the condensing unit.

Make sure you do not remove the panel protecting the electrical components to prevent causing damage to them.

Once the panels are removed, remove the fan blade and motor.

There is electrical wiring that is holding it in place so you will not be able to completely remove it, but you want to have access to the inside of your coils.

Next, you want to grab your hose with a decent amount of water pressure and begin to rinse the coils from the inside out.

You do not want to use too high of pressure to avoid damaging the fins.

The purpose of cleaning from the inside out is because your fan pulls the air through the coils and out the top of the unit.

Therefore any dirt will get pulled into the coils from the outside.

When you clean the coils from the inside out it removes the debris in the most efficient way.

There are two things to keep in mind when cleaning your outdoor coils.

First, you should only use water.

Using any chemicals can cause damage to the coils.

Second, do not attempt to wipe the coils with a cloth. Use only the water pressure to clean the coils.

Using cloth can cause damage to the fins preventing them from working properly.

Once the condensing coil is all clean, you can close up all the panels, and the condenser fan, and reconnect the power.

You can also clean your coils from the outside however, we do not recommend doing so because long term, you are pushing more dirt and debris deeper into the coil fins.

An evaporator coil is a little more complex to clean because it has a sealed housing making it hard to access.

It can get even more difficult if it is located in a tight space such as an attic or crawl space.

The tools you need are a drill with a nut head, a water sprayer, and a cleaning solution.

Make sure you check that you are using an approving cleaning solution for the indoor evaporator coil.

Coils are made of either copper or aluminum and using the wrong cleaning agent can cause damage and deterioration to the coil.

First, you need to open up the access to the coil.

This involves opening up the screws to the coil housing and removing the panels.

Next, you want to spray the cleaning solution on the coil.

The solution breaks up any build-up of dirt, and contaminants on the coil making it easier for the water to rinse it off.

Let the solution sit for a bit and then begin to spray the coil with water.

The water will drain through the condensation pan and line out to your gutter.

As it drains it will wash away all the dirt, dust, debris, and any contaminants on the coil.

Make sure the water spray isn’t high pressure and doesn’t force out a large volume of water.

If you pressure wash it or use large volumes of water the water will drip off the coil and onto the heat exchanger before it can make its way to the drain lines.

You also want to be sure that you rinse it with enough water to remove all of the chemical solutions.

Any solution that is left on the coil can deteriorate the coil over time.

Plus, any airflow through the evaporator coil makes it into your home and with it, will carry any vapor into your home.

After the indoor evaporator coil is clean, you can close up the housing, and you are done.

There are a few things to keep in mind.

Similar to the outdoor coil, you do not want to use a rag or anything to wipe the evaporator coil.

This can bend the fins causing damage to them.

This will then restrict the airflow through the coil.

You want to be sure to use an approved cleaning solution for the type of coil you have.

And, you want to be sure you don’t use high water pressure on the coils as well.

Again, we highly recommend having your AC coils professionally cleaned.

Below we will talk about the costs of cleaning your AC coils.

How to keep your AC coils clean

Naturally, your AC coils will get dirty over time.

However, there are simple steps you can take to slow down this process.

For your outdoor condensing coil, you want to be sure there are no plants or debris around your AC system.

If your system is located on the grass be sure to cut the grass short to allow proper airflow in the system.

When you or your gardener clean the yard, be sure that you don’t blow any debris towards the outside unit.

All in all, you want to ensure minimal debris at or around your system to prevent it from getting built up in the coil.

For your indoor evaporator coil, the most important and effective way to ensure your coils stay clean is by replacing your filters regularly.

Your filters not only remove the particles from your home, but also protect the internal components of your HVAC system.

The higher the efficiency rating of your filter the more particles it will be able to filter out.

It is essential you replace your filter regularly to avoid the filter getting clogged and not allowing airflow at all, raising your system's static pressure.

There is a thin line to walk when deciding what filter to use. You can see our guide on different filter efficiencies here.

AC Coil Cleaning Costs

When considering getting your AC coils cleaned professionally, you want to make sure you work with a reliable HVAC professional.

The price you can expect to pay to clean your indoor evaporator coil or outdoor condensing coil can vary depending on where you live.

The price to clean your indoor evaporator coil can vary from $250 to upwards of $500.

With the low end being in more rural areas and the higher end being in more urban cities.

The price to clean your outdoor condensing coil can vary from $100 to around $250.

Again, the low end is in more rural areas and the higher end is in more urban cities.


Your AC coils need to stay clean in order for your HVAC system to work properly.

A dirty evaporator coil can cause dirty sock syndrome, affecting your comfort and wellbeing.

Additionally, dirty evaporator coils and condensing coils both have negative effects on your HVAC system.

These effects include your system not cooling or heating (heat pumps) properly.

Additionally, parts of your system such as the compressor can fail due to dirty AC coils.

Your condenser coil is easier to clean than the evaporator coil nonetheless we recommend having both professionally cleaned to prevent damage to your system.

You can keep your evaporator coil clean by ensuring you have good filtration and staying on top of your filter changes.

You can keep your condensing coil clean by ensuring your outdoor condenser is away from any plants or trees and make sure to avoid blowing debris that way when gardening.

Additionally, you can purchase a protective cover to protect it during the winter, or a mesh net to protect larger leaves from falling in.

The cost to clean your coils can range from $250 to $500+ for evaporator coils.

And $100 to $250+ for condensing coils.

Cleaning the AC coils can prevent costly breakdowns in your system, saving you money on repairs. Therefore it is highly recommended to do so on a yearly basis.

Many HVAC professionals offer it as part of their yearly HVAC maintenance. So be sure to ask them if it is included.

We are always here to help. If you have any questions, contact us.