how to clean window ac unit

How to Clean A Window AC Unit Without Removing It in 10 Easy Steps

Ian Mutuli
Updated on
Ian Mutuli

Ian Mutuli

Founder and Managing Editor of Archute. He is also a graduate architect from The University of Nairobi, Kenya.
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A window air conditioner unit can be a lifesaver for people living in high-rise buildings or those whose homes lack good airflow from a central HVAC unit. Air conditioning keeps you and your family cool and comfortable, especially during the warm-to-hot summer months. However, all that heavy-duty use takes a huge toll on your AC unit, so you'll need to clean it regularly to keep it in good working order.

A dirty air conditioner will only cause you problems: mold and mildew buildup, air quality problems, dust problems, energy bill problems, etc. That being said, cleaning a window air conditioner probably sounds intimidating if you've never done it before. Luckily, the process isn't as complicated as it comes off. With the right tips on how to clean a window AC unit, you can easily keep it clean, functional as well as energy-efficient.

Why You Need to Clean Your Window Air Conditioner

Like any other major appliance, air conditioners drop off over time. They get dirty, the filters clog up and their efficiency falls. Therefore, they need regular cleaning and maintenance. However, if you come from a cold region, this isn't something you want to do in the heart of winter. Ideally, it should be part of your spring cleaning to get the air conditioning unit ready for winter.

When you clean your window unit regularly and thoroughly, you are assured of:

  • Cleaner air with less dust and irritants for allergies, asthma and different respiratory problems.
  • Fresher air. Removing the cloudy musk of air conditioner mold and dust leaves the air in your home smelling cleaner and fresher.
  • Smoother operation. A dirty machine has to work harder to deliver the same result. Lessening the working means the air conditioner becomes more efficient, hence it should run quieter.
  • Less energy consumption: As previously mentioned, the more efficient the AC unit, the lower the energy bills.
  • Extended lifespan: Since the machine is exposed to less stress, it naturally gets a longer, healthier lifespan.

What You’ll Need?

  • A bucket or sink nearby full of warm soapy water
  • A hand-held vacuum, ideally one with a soft brush attachment
  • A proper comb or soft brush
  • A spray bottle with relatively warm water & two drops of detergent or bleach
  • A cloth, small tower or rag you can get dirty.
  • Newspaper to set the AC on and where you’ll be working
  • A screwdriver
  • A small tray to place small parts and screws in
  • User manual. If you can't find it, just Google the model +"manual pdf".
  • Protective gloves for bleach and sharp fins
  • A fin comb (optional)
  • Can of compressed air (optional)
  • 3% Hydrogen peroxide

Steps to Clean Your Window AC Unit Without Removing It

These ten steps will walk you through how to clean your window AC unit without removing it:

Step 1: Disconnect Completely

Before starting the cleaning process, the first thing you do is unplug the window AC unit from the wall socket.

Step 2: Remove the Filter

The filter is designed to be easy to pull out. If you have a washable one, soak in the basin of warm soapy water. If it's a disposable filter, get the replacement ready.

Step 3: Remove the Case

Using the screwdriver, take out the screws and place them in the small tray. Remove the front grill and all other detachable components, especially the back grille, (removable) condensation drain as well as any part of the framing that can come off easily. Soak all these parts in warm soapy water and let them sit.

Step 4: Vacuum & Wipe

Use the vacuum to get any apparent balls of dirt and dust out of the unit. Next, use the slightly dump cloth for an initial wipe over these obvious areas, like early mold patches.

Step 5: Clean the Air Filter.

After vacuuming and wiping, grab the air filter from the bucket of soapy water. Using the soft, bristle brush, brush the filter gently until it's as clean as necessary. Afterward, air-dry it completely before reinstalling.

Step 6: Clean Air-Conditioner Coils and Fins.

Find the evaporator coils and fins in your AC unit, which turn warm air into cool air, then clean them with a toothbrush or other soft-bristle brush. Handle the coils and fins gently and carefully to avoid bending or damaging them. Next, spray the coils and fins with compressed air to eliminate any remaining dirt and dust.

Step 7: Clean the Interiors

First, use the spray bottle with a few drops of detergent to spray over all interior surfaces you'll be able to wipe down. Worry not, window units are designed to handle water; they are dehumidifiers, after all.

As the interiors soak in the spray, move to Step 8.

Step 8: Clean the Grill and Exteriors.

Using a damp cloth or rag, clean the air conditioner's grill. If there's a lot of, detach the grill according to the manufacturer's instructions and dip it in the warm soapy water. Use a brush or rag to clean in between the grill's gaps. Remember, the grill has to dry completely dry before reinstalling.

Next, use the damp cloth to wipe down the top and sides of the AC unit. If your AC comes with a drain pan and/or drip tray, ensure that you empty, clean and wipe them too. Allow them to dry completely before reattaching to the AC unit.

Lastly, using hydrogen peroxide, treat the exterior areas of the unit where air flows through to prevent mold and mildew buildup.

Step 9: Wipe Interiors

Use a wet cloth to give the soaked interiors a good wipe down. Do this for pretty much any area you can get your hands on, particularly the fin and fan blades. Once you have gotten as much as you can out of the window AC unit, leave everything to dry completely.

Step 10: Reassemble

Allow enough time for all different parts to dry completely before putting them back in the unit. Then, place each part back in the order you took them off. If you have any doubts, go back to the owner's manual, which should guide you accordingly.

Window Air Conditioner Best Practices

Now that you've gotten to know how to clean a window air conditioner, the following quick tips should help you to get the most out of it and make sure it stays at its best:

  • Keep the filter clean. Cleaning your filter once a month should be fine, but you might have to do it more often, especially when it's a tough cold season for the unit.
  • Keep the fins straight. The cooling fins should always be as straight as possible, during and after deep cleans. The fins convert hot air to cold air, which is why they should always run straight up and down.
  • Keep it running. The more you use the AC unit, the less the likelihood of mold building up internally. What happens is (especially stale) moisture breeds mold, so mold starts to creep up if the air conditioner just sits on the window on a damp day. However, you should always shut it down if you're not using it.
  • Keep it in the shade. An air conditioner starts to deteriorate when left exposed to the sun. If possible, mount your unit on the window that gets the most shade in the house.
  • When in doubt, consider a service. If your AC unit has been underperforming and you can figure out the reason, it would be best to consult a professional.
  • Store it well. Keep the window unit in a cool, dry place when not in use. Over-exposure to the elements leads to accelerate the onset of rust and other mechanical issues.

Monthly Check-Ups

Once you've cleaned your window air conditioner thoroughly, it only requires a check once a month or so. Doing this check-up on your unit is super simple. Simply clean the possibly dirty air filter, empty the condensation tray, and then quickly inspect the machine. If everything looks good from the outside, you're good to go.

However, if you smell mold or find something out of the usual, take the case off and have a closer look. You can follow that up with the appropriate spot cleaning if necessary. Finally, reach out to a professional if you find an issue you can't figure out.

Frequently Asked Questions (FAQs) on Window AC Cleaning

1. What are the risks of a dirty window air conditioner?

A dirty window air conditioner is quite risky in several ways. It lowers the cooling efficiency of the unit and increases its wear and tear. The dirt and mold also lead to foul-smelling air as well as the spreading of dust and dander, which aggravates allergies and respiratory problems.

2. Can I spray water on the air conditioner?

Yes! Window air conditioners are pretty sturdy appliances, plus they deal with moisture in the air. However, that doesn't mean soaking your unit; we recommend spraying when you need to wide down.

3. How often should I clean my window AC unit?

The best time to clean a window air conditioner is around summer when you take it out of the cupboard. That's when the dust, mold and grime have built up. In conclusion, window air conditioners only need a brief check-up every month or two is more than enough after a deep clean. But you might have to do it more frequently depending on how much you're using it.

Image Source:

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.
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