Yes, You're Supposed to Be Cleaning Your Window AC Unit – Here's How

So, you’ve just moved into your apartment, and there’s no central air. Instead, there’s a handy window AC unit doing its best to keep your new space cool. You probably won’t worry about it right away, but cleaning a window AC unit is a necessary task on the seemingly never-ending list of things to do when it comes to living on your own. Keeping an AC unit clean will ensure that it works properly, prevent harmful bacteria from entering your home, and stop any unwanted mould growth on the unit. Since sanitizing a window AC unit is one of those tasks you never, ever worry about until you have to do it, POPSUGAR reached out to experts to help answer the question: what is the best way to clean a window AC unit?

How Often Should You Clean a Window AC Unit?

Ideally, window AC units should be fully cleaned biannually. “You should deep clean a window AC unit twice a year,” says Michael Rubino, president of All American Restoration, council-certified mould remediator, and author of “The Mold Medic: An Expert’s Guide on Mold Removal.” “Clean it once before turning it on and once before shutting it down for the season.” But this doesn’t mean you should neglect the window AC unit on a day-to-day basis. Rubino suggests cleaning a window AC unit as part of your daily routine to maintain its cleanliness: “Owners should also take additional steps to clean the unit weekly and monthly as well.”

How Do You Clean a Window AC Unit?

There are two strategies for cleaning your window AC unit. The first involves using hydrogen peroxide, and the second can be done with cleaners you already have in your home. For the first method, you’ll need eight-percent hydrogen peroxide, a vacuum, a screwdriver, and microfiber cloths. For the home-cleaner method, you’ll need a bucket of warm, soapy water; a vacuum with a soft brush attachment; a spray bottle with warm water and dish soap; a screwdriver; and some rags. First up, Rubino walks us through his tried-and-true method for cleaning a window AC unit with hydrogen peroxide as the main cleaning component.

How to Clean a Window AC Unit With Hydrogen Peroxide

1. Unplug the window AC unit.
2. Remove the window AC unit. “Use a screwdriver to remove it from the window, and take it outside,” Rubino says.
3. Remove the filter and grill.
4. Decontaminate the grill with hydrogen peroxide. “After you remove the grill, spray it with eight-percent hydrogen peroxide, and then wipe with a microfiber towel,” Rubino says. “Use a small scrubbing brush for any hard-to-reach areas.”
5. Vacuum the inside of the window AC unit. Rubino suggests using a HEPA vacuum – a high-efficiency particulate air vacuum, which traps even the smallest of particles – for the best results. “HEPA vacuum the inside of the machine, making sure to get into every crack and crevice possible,” he says.
6. Vacuum the fins – with caution “Use the soft, bristled attachment for the fins to make sure as many particles as possible are removed,” Rubino tells POPSUGAR. “Make sure to carefully tackle this step to avoid bending the fins.” In the event that a fin gets bent, Rubino suggests gently pushing it back into place.
7. Spray the window AC unit’s interior with hydrogen peroxide. “Spray down the interior with eight-percent hydrogen peroxide, then allow it to sit for around 30 seconds before wiping it with a microfiber rag,” Rubino says.
8. Sanitize condenser coils with hydrogen peroxide. “Spray the condenser coils with eight-percent hydrogen peroxide, allow it to sit for five minutes, and then wipe them with a microfiber towel,” Rubino says. He recommends using a small, soft-bristled brush for any difficult areas.
9. Remove, empty, and clean the drip tray with hydrogen peroxide. “Allow it to sit for five minutes after cleaning, and then wipe it with a microfiber towel,” Rubino says. He makes sure the drip tray is completely clean before putting it back in.
10. Restore all the newly cleaned components back into the window AC unit, and replace the filter if need be. Filters should be replaced every one to three months to prevent mould growth.
11. Spray the exterior with hydrogen peroxide. Rubino allows it to sit once sprayed and then rubs it dry with a microfiber cloth.

How to Clean a Window AC Unit With Household Supplies:

Cleaning a window AC unit can also require just a few supplies you likely already have around your apartment. Lenny Brickowsky, an ACHP-certified handyman and consultant at Julieie Salone, provides his method for cleaning a window AC unit using household supplies.

“First, gather the supplies,” Brickowsky says. “You will need a bucket for warm, soapy water; a vacuum with a soft brush attachment; a spray bottle with warm water and two drops of mild dish soap; cloths to wash the AC unit; a screwdriver; and a safe place to place the screws and a fin comb, in case you need to straighten coils.”

1. Unplug the window AC unit.
2. Remove the grill and filter.
3. Soak the grill and filter. “You may need to let them soak in a bucket of soapy water and let them dry, or you may need to replace it,” Brickowsky tells POPSUGAR. Although the window AC unit’s manufacturer guide will recommend how often, Brickowsky has a rule of thumb: “Filters should be cleaned or changed every one to three months.”
4. Remove the case from the window AC unit. “You can use the screwdriver to do this,” Brickowsky says.
5. Remove each part of the window AC unit and soak them. “You’ll need to remove all the parts, including the drain pan,” Brickowsky says. “You can soak them in warm water to get them clean.”
6. Clean the drain pan. This is a key component of deterring mould growth.
7. Vacuum inside the window AC unit. “Vacuum the parts inside the AC unit to remove any dust balls or other unwanted elements,” Brickowsky says.
8. Spray the inside of the window AC unit. Spray the inside of the unit with mild dish soap and water.
9. Remove the back of the window AC unit and clean the condenser coils. Brickowksy sprays the condenser coils with the same dish-soap-and-water mixture. “Allow the dirt to run off, and then rinse it off,” he says. “You can use a hose for this, or you can get another spray bottle with warm water.”
10. Reassemble the window AC unit.
11. While cleaning your window AC unit, the fins might get bent. If that happens, don’t stress. Brickowsky suggests using a handy tool to help put them back in place: “If you see any fins bent, gently straighten them with the fin comb.” You can snag this combo fin comb and cleaning brush for $12 on Amazon.

How to Prevent Mold Growth in a Window AC Unit

By keeping your window AC unit clean, you’ll also prevent mould growth. “Cleaning frequently and thoroughly not only helps ensure the machine runs correctly and extends its shelf life, but it’s also crucial for avoiding mould growth in the machine,” Rubino says. Keeping this mould growth at bay is important for your health, he notes: “Once a colony is established, it will start releasing microscopic spores into the air, which will then get blown throughout the room.”

Rubino offers a few handy solutions for mould-growth prevention in and on your window AC unit. “Maintain indoor humidity between 30 percent to 50 percent,” he says. “Any higher, and mould can form.” Keeping up with the replacement of your AC filter is another simple way to prevent mould growth. Finally, check your window AC unit’s settings. “Turn on the humidity setting,” Rubino says. “If the machine has this setting, always opt for it.”