How To Get Rid of Mold in a Window Air Conditioner (6 Step Guide)

Want to get rid of mold in your window air conditioner? You’re in the right place!

Window air conditioning units can be a convenient, inexpensive way to cool down and circulate fresh air almost anywhere in your home. However, due to the liquid and dark ducts in any window air conditioner, they can make for easy places for mold to grow.

In this proHVACinfo guide, you’ll learn:

  • The gear you’ll need to get rid of mold in your window air conditioner
  • How to disassemble your air conditioner and inspect it for mold
  • Specific steps to get rid of mold from your air conditioner
  • How to know when it’s time to buy a new air conditioner

What You Need To Know About Getting Rid of Mold in a Window Air Conditioner

If you think your air conditioner might have mold in it, it’s important to act quickly.

According to the CDC, exposure to moldy environments can cause a variety of health effects. Similarly, the EPA says mold spores produce allergens and irritants, and touching or inhaling them can irritate the eyes, skin, nose, throat, and lungs. Inhaling or touching mold or mold spores can cause allergic reactions in sensitive individuals.

Mold can even cause asthma attacks in people with asthma who are allergic to mold!

Unfortunately, under some circumstances there can be so much mold on the unit that it’s nearly impossible to completely remove all of it. In these situations, a new air conditioning unit is needed because if the mold is not entirely removed, it will grow back over time.

Read on to determine if your air conditioning unit needs replaced.

Supplies You’ll Need For Getting Rid of Mold in a Window Air Conditioner

  1. Protective eye wear – This is important to prevent mold or mold spores from getting in your eyes. For that reason, safety goggles that do not have ventilation holes are best to minimize the chance spores come in contact with your eyes.
  1. Mask – Just as we want to prevent mold from coming in contact with your eyes, we want to avoid accidentally breathing in any mold spores, so wearing a mask is recommended. Most authorities recommend an N-95 mask (check the label for “N-95” and “NIOSH”).
  1. Gloves – Protective gloves will help you avoid touching mold or spores. To clean your window air conditioner, you can use standard household dish soap, so household rubber gloves may be used.
  1. Fin Comb – Chances are you’ve never heard of this tool until now. A fin comb is a specialized tool used for cleaning and straightening the fins in your air conditioner. Not sure what this means? See step 5 below for a full explanation.
  1. Screwdriver – You’ll need this to fully disassemble and thoroughly clean the air conditioner
  1. Dish Soap, sponge and a bucket – What we’ll use to clean the mold



Step 1: Unplug your window air conditioner and remove it from the window

In this guide, you’ll be taking the air conditioning unit apart and cleaning the inside with liquid, so it’s crucial the air conditioning unit is unplugged.

You’ll also need an open surface to clean the air conditioning unit on, so if the unit is currently set up in a window, remove it before proceeding.

These units can be heavy and awkward to remove by yourself, so have someone help you if needed.

Note the EPA recommends not running a system you suspect is contaminated with mold, as it could spread mold throughout your home.

Step 2: Remove the filter and front grill from the air conditioning unit

The filter looks like a fine screen inside a plastic frame. The filter is always found just behind the front grill (the front covering) and is typically reusable.

The process for removing the front grill is different for different models. The front grill may have latches you release with your hands, or may require removing small screws with your screwdriver. Your filter may simply slide out from behind the grill (if that’s the case, you’ll see a tab for the filter sticking out from behind the grill).

If you are unsure how to remove your filter, look in your owner’s manual or Google the brand of your window air conditioning unit. If you want to “deep clean” your air conditioning unit, you can use your screwdriver to remove the entire plastic casing.

If you choose to do this, we recommend taking pictures as you disassemble the unit so you remember how it all fit together for reassembly (step 6).



Step 3: Clean the filter

If it’s been a while since you’ve cleaned the filter (or this is your first time cleaning it) you’ll likely notice a thin layer of dust, debris and potentially mold on the filter. To clean it, hold the filter under running water until the dirt is removed.

We don’t recommend applying cleaning products to the filter, as chemicals in the cleaning agent will circulate in the room once you replace the filter.

Step 4: Clean the interior of the air conditioner

Once the front grill and filter have been removed, you’ll have a chance to see the extent of the mold in your air conditioning unit. The mold can look like black, brown or blue spots that don’t appear to have a smooth or consistent texture and may be slightly raised from the air conditioning unit itself.

If there are a few isolated mold spots on the front of the interior of your air conditioning unit (near the front grill), there’s a good chance your unit can be cleaned. However, if there is significant mold throughout the unit (and particularly if the mold has spread into hard-to-reach ducts, etc.), the unit may need replacing.

Scrub anywhere you see spots like this!

Fill your bucket or bowl with warm water and mix in some dish soap. Carefully wipe or scrub the mold until it comes off, paying attention so as to not get any water on the electrical components inside the air conditioner.

Step 5: Straighten and clean the fins

The fins for your window air conditioner comprise two sets of metal sheets (they each look like a grill) found in two places: inside the air conditioner (facing the room), and on the exterior toward the back of the air conditioner (facing outside).

These fins (the metal sheets) allow air to flow smoothly through the air conditioner. Over time, these fins naturally attract dirt and debris and so can be an easy source of mold. Moreover, the fins are made out of thin aluminum, and so are easily bent.

When the fins bend, it restricts air flow and prevents your air conditioner from working properly. This makes the air conditioner work harder, which means a higher electric bill for you and having a window air conditioner that needs replaced more easily (due to overuse).

This is where the fin comb comes in handy. Place the comb at the top of the air conditioner inside the fins so the teeth of the comb fit between the metal sheets. Carefully guide the comb straight down to the bottom of the unit.

This will straighten the fins and remove any debris or mold. Note: This can take 10 – 15 minutes for each set of fins.

The fins are delicate, so be careful when straightening to not break any.

Step 6: Wait for the air conditioner unit to fully dry and reassemble

Now that you’ve cleaned the filter and interior of your air conditioning unit, wait for the unit to fully dry by leaving it in a cool, dry place. This can take up to 24 hours. Then, reassemble the unit in the same way you disassembled it earlier, taking care to replace the frame and screws in the same manner you removed them above.

Any odor should be greatly reduced or eliminated. However, as mentioned above, if the mold starts to regrow, you likely have mold deep in the air conditioner and will need to replace the unit altogether.

Stephen Marks

Stephen Marks

Stephen is an HVAC and home-repair enthusiast. He's here to answer any of your questions about HVAC!

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Stephen Marks

Stephen Marks

Stephen is an HVAC and home-repair enthusiast. He's here to answer any of your questions about HVAC!

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