How to clean a window air conditioner, according to experts

We don’t always have the answers, but we have some people on speed dial who do — which is why we present to you our series FYI where we have experts explain if lip balm is actually bad, how often you should wash your hair and more. 

Similar to buying a mattress, shopping for a powerful air conditioner is a great, albeit pricey, way to make a home feel complete. This is especially true if you don’t have central air and rely on a window unit to get you through the sweltering summer heat. If you want to make sure your appliance keeps your home cool for years to come and doesn’t develop potentially harmful bacteria, it’s important to know how to clean your window air conditioner. “Cleaning your window air conditioner helps prevent mold/mildew and other debris from building up and helps to keep the air blowing into the room cleaner,” says Carl Prouty, a sales specialist at Abt Appliances and Electronics. “Generally you’ll want to clean the entire unit once a year, and you’ll want to clean the filter every 2-4 weeks throughout.”

To find the best way to clean a window air conditioner, I spoke with Prouty and Mike Mayer, co-founder of the air conditioner brand Windmill, for their guidance and product recommendations. 

There are many different types of air conditioners available, such as window, portable and large outdoor units. For this article, I’m mainly focusing on window air conditioners. I’m going to stick to more of a surface-level clean of your window air conditioning unit, such as cleaning the outside parts and the filter as well as removing dust, rather than a more in-depth clean that might require taking the inside of the air conditioner apart, cleaning out the coil, etc. Some units even have a light that turns on when the filter of the air conditioner needs to be cleaned, according to Prouty. If you want to do a more thorough cleaning of your entire air conditioning unit, I’d recommend consulting an HVAC expert to ensure you don’t accidentally damage the unit in the process. 

There are a few easy steps to follow when cleaning your window air conditioner at home. Here’s how our experts recommend going about it:

1. Start by turning off and unplugging your window air conditioner from the outlet.
2. Next, remove the filter. This is often behind the front grill. You can remove it by pulling it out from a slot on the side of the unit, usually using a small tab in the middle. If you haven’t cleaned this recently (or ever) it will likely have accumulated a lot of dust on the surface.
3. Use a handheld vacuum and/or the crevice tool attachment on an upright or canister vacuum to remove the dust stuck to the filter. Alternatively, you can dump the dust directly into your trash can, though a vacuum will be more thorough.
4. Use a small, thin crevice-cleaning brush to clean the surface of the filter to get rid of any residual dust. Run the filter under warm water in the sink. Optional: Scrub the filter with a brush and warm soapy water. Rinse thoroughly with water and let dry completely before putting it back in the air conditioner.
5. Dampen a microfiber cloth with water and coat it with a small amount of dish spray. Use it to wipe down and clean the front grill and control panel of the air conditioner. To clean in between the grates, scrub with a crevice brush or clean with a duster for cleaning in between blinds. For a more thorough cleaning, remove the grill and use the same method.

All of the products below have at least a 4-star average rating from 500 reviews or more on Amazon and/or are cleaning products I or other NBC Select staff members have tried themselves. Some of the products are also ones that experts have recommended for similar cleaning stories.

Black & Decker Dustbuster Cordless Handheld Vacuum

A handheld vacuum is helpful when cleaning small messes, especially ones on upholstered surfaces like couches. It also happens to be good at removing the dust from your air conditioner’s filter. While you can manually remove the dust from the filter directly into your trash can, you’ll probably end up with dust blowing into the air and a filter that’s still not thoroughly clean. This powerful and cordless Black & Decker Dustbuster Cordless Handheld Vacuum has a 4.4-star average rating from 51,799 reviews on Amazon. It also has multiple attachments as well as a dirt bowl you can clean in the sink.

Trycooling 3-Piece Groove Cleaning Brush Set

Small cleaning brushes are sometimes the best way to clean the small crevices in and around your air conditioning unit, including the side panels and the surrounding window sill, which tends to collect a lot of debris. This set, which has a 4.3-star average rating from 15,793 reviews on Amazon, includes a curved brush, a small bristled brush with a dustpan and a gap tool for cleaning in between the vent of the air conditioner grill. 

Home Excel Microfiber Cleaning Cloths

These cleaning cloths are great for wiping down areas all over your home, including your air conditioning unit. I’ve used these before and they’re the perfect size for cleaning the outside of a window air conditioner by hand. All you have to do is dampen it slightly with water and/or use it to dry off the filter after cleaning it. They’re extremely absorbent, lint- and scratch-free and you can clean them in the washing machine. 

Dawn Platinum Power Wash Dish Spray

This popular item is great for so much more than cleaning dishes. It’s commonly recommended by cleaning experts for tasks like cleaning the inside of your refrigerator or cleaning the filter of your dishwasher. You can also use it to clean the filter of your air conditioner once you remove it from the unit. Spray it on, scrub and thoroughly rinse before allowing it to dry.

While a lot of window air conditioners differ in style, design and energy level (known as BTU, or British thermal units), many have the same parts. Below, I briefly explain some of the parts of a window air conditioner, mainly the ones you’d clean in a surface-level job. 

• Grill: Sometimes spelled grille, this is the main part of the front of a window air conditioner. It’s essentially a vent or row of grates that covers the filter and is usually to the side of or below the dials. Some modern brands, such as Windmill, however, have grills that are made of hundreds of small holes rather than grates.
• Filter: This is the screen that goes right behind the grill of the air conditioner. Over time, it collects a lot of dust and debris from the air, which sticks to the surface. This is one of the main parts to focus on cleaning when taking care of your window air conditioner.
• Front panel: This is the part of the air conditioner with the control dials, knobs or buttons used to control the power level of the unit and the temperature. Many function either manually or digitally.
• Side panels: These are the pleated panels that go on the sides of the air conditioner to secure the unit in the window sill. These often come with foam lining that you can place in between the ends of the panels and the window sill to prevent small drafts, bugs or rain from coming. This is also the part that people often drill into the metal reinforcement of the window to make sure the unit stays in.
• Back unit: The back of the air conditioner is comprised of many different parts, including the evaporator coil, compressor coil, condenser coil, fan and other parts that use refrigerant, a chemical that helps convert warm air into cool air and vice versa, according to the United States Environmental Protection Agency (EPA). All of these parts are covered with panels. In this article, I’ll focus on cleaning the parts mentioned above. 

In terms of cleaning a window air conditioner, no, it’s not recommended to spray water or other liquids directly onto or into the unit. That’s because it could potentially damage important parts inside. “A soft cloth with warm water and a mild cleaner will do the trick,” says Mayer. “Just be sure the air conditioner is unplugged and that no water or liquid gets inside the vents.”

Our experts recommend against using any harsh chemicals such as bleach or all-purpose cleaner to clean your air conditioner. Like with water in general, these products can damage and corrode the unit, according to Mayer. “An aggressive cleaner can corrode key internal parts, like the evaporator. And, depending on the unit, could damage the metal or plastic housing,” he says. “For the filter, just use warm water under the sink.”

You don’t have to change your air conditioner’s filter (unless it’s broken), but you should clean it out regularly, according to Mayer. “We recommend cleaning the reusable mesh filter once every month during the summer season,” he says. “If the filter is not cleaned properly, the AC won’t be able to pull in the room air efficiently, and the unit can break.”

• Carl Prouty is a sales specialist and video producer at Abt Electronics, an electronics and appliance store based in Glenview, IL. 
• Mike Mayer is the co-founder of air conditioner and appliance brand Windmill.

I’m a commerce editor at NBC Select, where I cover kitchen, home, cleaning and wellness-related product roundups. I also write many explainers on cleaning, such as how to clean different types of clothing, how to clean a mattress and the best way to clean a dishwasher. I spoke with multiple experts with experience in cleaning and home appliances for this story.