How to Clean Your Window AC Unit so Your Home Stays Cool This Summer

updated Jun 7, 2024
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Credit: Alexis Buryk

If you’ve lived in your home long enough with window AC units, you may have noticed something mildly alarming: After a while, the units don’t work as well as they used to. I have the privilege of having window air conditioning units, and when it happened to me, I got concerned. (I basically live for cool air.) 

So I did something I have never done in all my years as a renter: I cleaned the window units. They were disgusting — but it made such a difference in my home. You should probably go clean yours right now, too. Here’s how to clean a window AC unit.

Quick Overview

How to Clean a Window AC Unit

You should clean your window AC unit at least once a year, with the filter being cleaned more regularly and replaced every one to three months. Before you start cleaning, you’ll want to gather the necessary tools — like gloves, a screwdriver, vacuum, and cloth — and locate the AC unit’s manual (for any specific instructions or watch-outs). Then, follow the seven steps below to get your window AC unit clean.

How Often You Should Clean Your Window AC Unit

On the whole, your window unit should be cleaned at least once a year. But that might not be enough, depending on your environment, says Alicia Sokolowski, president, and co-CEO of AspenClean, a company that provides all-natural, chemical-free cleaning products services.

“The frequency of cleaning may vary depending on factors such as the environment, usage, and air quality,” she says. “If you live in a dusty area or use your AC unit frequently, you may need to clean it more often.”

It seems like pretty apt advice considering all the wildfire smoke that’s been floating through the air lately. To be clear, annual maintenance refers to the entire window unit and all parts of it. The filter inside the unit, Sokolowski says, should be replaced every one to three months.

Do You Have to Remove a Window AC Unit Before Cleaning It?

Great news for those of you that live in higher homes: You don’t generally need to remove the whole unit to clean it. 

“Most window AC units are designed to be cleaned in place,” Sokolowski says. “However, it’s important to follow the manufacturer’s specific instructions for your particular model.”

This is perfect for me — I live on the second floor, and the window units are held in place permanently with wood panels. The only bad part about this is that I can’t reach the outside of the unit without a tall ladder that I don’t have. So don’t worry if you can’t remove the unit or reach the outside of it. I couldn’t either, and the cleaning was still a success.

What You’ll Need

The first step for any project — cleaning or otherwise — is assembling the proper tools. Here’s what you need to clean your window AC units.

  • Cleaning gloves (optional but helpful)
  • Screwdriver
  • Vacuum cleaner and attachments
  • Soft brush or fin comb 
  • Dish soap or another cleaning solution, like an all-natural one
  • Water
  • Bucket, tub, hose, or kitchen sink
  • Clean cloth or sponge
  • Face mask and long sleeves (optional but helpful if you have dust allergies)

How to Clean a Window AC Unit

Here are Sokolowski’s steps to follow to clean a window AC unit.

Credit: Jennifer Billock

Step 1: Turn off and unplug the window unit.

Water and electricity don’t mix. Be safe and unplug it before starting to clean.

Credit: Jennifer Billock

Step 2: Remove the front cover.

The front cover on my unit doesn’t come off completely; it just pops open and hangs there. But you may need that screwdriver to remove the front panel of yours. Once the cover is off, you’ll be able to easily access the filter and all the coils.

Credit: Jennifer Billock

Step 3: Remove and clean the filter. 

My filter slid right out of the unit, but check the manual on how to remove yours. You may be surprised by how dirty the filter is — I know I was. To clean it, you can try vacuuming it (which absolutely did not work for my filters, thanks pets) or washing it with your cleaning solution and water. I cleaned mine in the tub and also used a toothbrush to lightly scrub off the dirt. Once it’s clean, lay it out to dry. It’ll need to be dried completely before you put it back in the window unit.

Credit: Jennifer Billock

Step 4: Clean the coils.

While the filter is drying, clean the coils. Use your soft brush or fin comb to lightly brush off any dirt, dust, or debris. I ended up using a makeup brush, and it worked perfectly. Then, vacuum up all the residue. You can also use a vacuum with the brush attachment to clean the coils, as long as you’re gentle.

Step 5: If you can access the outside, clean the condenser coils.

Only if you can safely access the outside of your window unit, then you should consider doing this step. You should remove any first, leaves, or debris with a soft brush.

Credit: Jennifer Billock

Step 6: Clean all the surfaces of the unit. 

Using a damp cloth or sponge, wipe down all the hard surfaces on the inside and outside to remove any dust or dirt. You don’t want to get any water into the coils, so be sure your cloth or sponge is truly damp and not dripping at all.

Credit: Jennifer Billock

Step 7: Reassemble the unit.

Put the filter back in, reattach the cover, and enjoy new fresh, and clean air!

Credit: Jennifer Billock

All told it took me about an hour of active time to clean both of our window units. The filters took a while to dry, so feel free to clean everything and then do something else for a while before reassembling the unit. And don’t forget to put the task on your annual maintenance list!

How to Keep Your Window AC Unit Clean Longer

Now that your window unit is fully cleaned, it’s time to think about ways to keep it that way. If possible, add a cover over the unit during the offseason, says Asif Bux, co-owner of HVAC company Comfort Union. That’ll stop dust and debris from getting into the unit. You should also make sure the window seals around the unit are intact — they give extra protection from the elements. Bux’s final tip? Use an air purifier. Put it in the same room as your window unit to cut back on the amount of dust and allergens that might get drawn into the machine.