How to Clean a Window Air Conditioner

Co-authored by Victor Belavus

Last Updated: October 19, 2022 References

Cleaning your window air conditioner regularly is vital to keeping it in good working order. Remove and rinse the filter monthly during the cooling season. When it’s not in use, store the unit indoors and cover it with a sheet of plastic or tarp. Before you install it at the start of warmer weather, disassemble it and give it a thorough seasonal cleaning. Comb its aluminum fins, blow the coils with compressed air, and vacuum and wipe down the interior tray. If your unit is especially dirty, deep clean it with a coil cleaner or oxygenated household cleaner.

Method 1

Method 1 of 4:

Basic Cleaning

1
Look and smell for signs of mildew. If a mildew smell is noticeable when you first turn the A/C on, this method may help.
2
Fill a spray bottle with hydrogen peroxide. The 3% solution sold in stores will work.
- Do not use alcohol, as this is flammable and could start a fire.
- Do not use bleach, as those fumes are toxic and bleach could damage the unit.
- While safer than bleach or alcohol, hydrogen peroxide should still be clearly labelled and kept out of the reach of children.
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3
Turn the unit off. Spray the intake area and outflow area on the front of the unit.
- Avoid getting spray in eyes or inhaling it. Once it settles on surfaces, the fumes are no longer a concern.
- Rinse hands after spraying.
4
Allow it to dry. Then turn the unit back on.
- Spraying when the unit is turned off for the night is ideal, as that allows plenty of time to dry before morning.
5
Do a deeper clean if needed. If this method isn't sufficient, remove the filter, with the unit off, and spray further inside the unit.
- Place a drip tray underneath the unit to catch any drips, which might otherwise bleach carpet, fabric, or wood.
- A turkey basting tray is one possible option.
6
Avoid turning the unit on and off often. Before the condensate evaporates, that's the ideal breeding period for microbes. While the unit is on, the temperature extremes and continuous flow of condensate washing old water outside (you may see it dripping) prevents the build-up of microbes.

Method 2

Method 2 of 4:

Cleaning the Filter Monthly

1
Remove the unit’s front panel to access the filter. Turn the unit off and disconnect the power cord before removing the front panel. Your air conditioner’s front panel is secured with screws or tabs. Remove the panel, locate the filter, and pull it out of its slot.^{[1]
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- Depending on your model, you’ll either pull the filter up or slide it down out of its slot. Check your manual for specific information about how to remove your front panel and filter.^{[2]
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2
Run water through the filter. Rinse the filter under running warm water. Use a vacuum hose attachment to clean the filter if it’s caked with dirt or grime.^{[3]
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- It’s best to clean your filter at least once a month. Clean it more often if you live in a dusty environment or have pets.^{[4]
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  Trustworthy Source
  U.S. Department of Energy
  Official site for the U.S. Department of Energy, which provides resources related to energy safety, conservation, and efficiency
  Go to source}
- Replace your air filter at least every 3 months.^{[5]
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  Expert Source
  
  Victor Belavus
  Air Conditioning Specialist
  Expert Interview. 6 May 2020.}
3
Let the filter dry then put in back in place. Shake off excess water and pat the filter with a dry towel. Let it sit out until it’s completely dry. When it’s dry, put the filter back into its slot and replace the unit’s front panel.^{[6]
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- Never run an air conditioner with a wet filter or without a filter.
4
Replace a worn filter. If your filter is worn or torn, you should replace it. If the filter is designed specifically for your unit, identify your model number and order a new one online or from your unit’s manufacturer.^{[7]
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Trustworthy Source
U.S. Department of Energy
Official site for the U.S. Department of Energy, which provides resources related to energy safety, conservation, and efficiency
Go to source}
- If your unit has a universal foam filter, you can purchase a cut-to-fit air conditioner filter online or at your local home improvement store.^{[8]
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Method 3

Method 3 of 4:

Deep Cleaning an Air Conditioner Seasonally

1
Remove the unit’s casing. Make sure the unit is off and that power is disconnected. Remove the front panel and fins that attach the unit to the window. Remove all the screws that attach the exterior casing to the unit’s interior. Carefully slide the casing away from the interior, and make sure you don’t snag the casing on any of the parts inside.^{[9]
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- The screws are small, so be sure to keep them in a safe place, like an envelope or small can.
2
Comb the aluminum fins. Use a fin comb or soft bristle brush to comb away dust and debris from the aluminum fins. You can find inexpensive combs specially made for window unit fins online or at a home improvement store.^{[10]
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- Wearing work gloves when you clean the fins will prevent you from getting cut.
3
Blow the coils and fan with condensed air. Purchase a canister of condensed air online or at your home improvement store. Spray into the fins and around the coils at the front and back of the unit. Blow away dust around the fan and motor at the center of the unit.^{[11]
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- You can also use a small brush to wipe away debris from the coils.^{[12]
  X
  Expert Source
  
  Victor Belavus
  Air Conditioning Specialist
  Expert Interview. 6 May 2020.}
4
Vacuum and wipe down the tray. Use a shop vac or vacuum hose attachment to remove debris from the tray, or the base of the unit’s interior. Spray it down with a household cleaner, scrub it, then wipe it with a damp cloth.^{[13]
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- Hand dry the tray with a clean towel then let it air dry for a few hours before reassembling the unit.
5
Store your air conditioner inside during cooler weather. When it's not in use, you should store your window unit indoors. Remove it from the window and keep it in your attic or basement. Cover it with a plastic sheet or tarp to keep dust and debris from accumulating.^{[14]
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Trustworthy Source
U.S. Department of Energy
Official site for the U.S. Department of Energy, which provides resources related to energy safety, conservation, and efficiency
Go to source}
- If you can't remove the air conditioner from the window, cover the exterior portion of the unit with a tarp or cover designed for air conditioners.

Method 4

Method 4 of 4:

Giving Your Unit a Deep Clean

1
Take the unit outside and remove its case. Place the unit on a table outside within reach of a hose. Take off the front panel and side fins that attach to the window. Remove the screws that attach the casing to the unit, store them in a safe place, and carefully slide off the casing.^{[15]
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- Choose a warm, sunny day to deep clean your air conditioner outside.
2
Spray the casing and interior with cleaning solution. Use an air conditioner coil cleaner or an oxygenated household cleaner. You can also mix warm water with a few drops of dish detergent. Spray the front panel, case, and window fins with the cleaner.^{[16]
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- Let the parts soak for about 10 minutes.
3
Scrub the unit and case and spray again if necessary. Use a soft bristle brush to gently scrub all the parts you sprayed with cleaning solution. If you encounter stubborn grime, such as around the fan blades, spray the areas again and let them soak for another few minutes. Then give them another scrub with your soft bristled brush.^{[18]
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4
Use a hose to rinse the case, coils, and tray. Set your hose on low pressure, as high pressure could damage the coils or aluminum fins. Spray down the exterior panel, casing, and window fins. Then hose down the coils, fan, and aluminum fins. Tilt the unit to spray and drain the interior base.^{[19]
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- Avoid getting the control panel wet when you hose down the unit.
5
Let your unit dry before reassembling it. Leave your unit outside to dry in the sun for a few hours. You can towel dry as much excess water as possible to make the process go faster. Wait until the unit is completely dry before you reassemble it.^{[20]
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Expert Q&A
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Question

What is the best way to clean a window air conditioner?

Victor Belavus
Air Conditioning Specialist
Victor Belavus is an Air Conditioning Specialist and the Owner of 212 HVAC, an air condition repair and installation company based in Brooklyn, New York. In addition to HVAC and air conditioning units, Victor also specializes in furnace repair and air duct cleaning. He has over 10 years of experience working with HVAC systems.

Victor Belavus

Air Conditioning Specialist

Expert Answer

Support wikiHow by unlocking this expert answer.

It's important to clean the drain pan after you clean the coil, because the tray is connected to your drain line. It can easily clog, causing leaks and water damage.
Question

Should I use industrial foaming coil cleaner on my window AC?

Victor Belavus
Air Conditioning Specialist
Victor Belavus is an Air Conditioning Specialist and the Owner of 212 HVAC, an air condition repair and installation company based in Brooklyn, New York. In addition to HVAC and air conditioning units, Victor also specializes in furnace repair and air duct cleaning. He has over 10 years of experience working with HVAC systems.

Victor Belavus

Air Conditioning Specialist

Expert Answer

Support wikiHow by unlocking this expert answer.

Read the label carefully if you're using a professional solution for coil cleaning. They sometimes differ for indoor and outdoor use.