Have you ever turned on your window AC unit and had a bad smell burn your nose? Before you put on a gas mask or toss out your unit, try cleaning it first.

Regular A/C unit cleaning needed, mileage may vary.

Most smells a unit makes could be due to extended use (or extended non-use, depending on the time of year). Mold and mildew growth is the most common reason, but it could also be simply dust, debris, or standing water in the drain pain. In this case, it’s time to clean.

According to the Department of Energy, once a year is the longest span between cleanings. However, depending on how long you use your window A/C unit, whether you smoke, or cook a lot of oily food, you may need to clean twice a year.

What if there’s mold in my window AC unit? How do I clean it out?

We’ve written on the topic of mold many times. We’ve talked about how to prevent it from spreading, how to find it when it’s hidden, and how to remove it from your home. It’s a frequent topic because mold prevention and removal is family protection, and there are few things we care about more than the health and wellbeing of the folks in the communities we serve.

There’s one mold-related topic we haven’t covered yet, however: what you should do if mold has found its way into one of your window air conditioning units. 

Short answer: you have to clean it out. 

Long answer: you have to clean it out, and we’ll walk you through exactly how to do it below.

Gear up

Before you clean anything, you’ll have to make sure you have the proper supplies to get the job done. Here’s what you’ll need:

• Protective gear (eyewear, N95 face mask, rubber gloves) 
• A Phillips head screwdriver 
• A wet/dry vacuum with attachments 
• A large bucket (5-gallon or more) 
• Laundry detergent 
• Water 
• Bleach 
• Dish soap 
• Rags and/or brushes for scrubbing

Once you’ve gathered everything you need, you can then move on to the project itself. 

Step 1. Put on all your protective gear. This should include eyewear like goggles or a face shield, a N95 or better face mask, and rubber gloves. Mold can be toxic if inhaled, so it’s important to always err on the side of caution.

Step 2. Turn off your window air conditioning unit, unplug the unit, and safely remove it from the window frame. Take it to a well-ventilated place where you’ll be able to work on cleaning it comfortably. 

Step 3. Remove the grille on the front of your unit’s body. You can usually do this by grasping the outer edges of the body frame, pulling forward, and then down. It should sort of click and slide out of place. If the front grille appears to be screwed in place, remove the screws before attempting to pull it off. 

Step 4. Once the grille is off, you’ll be able to see the air filter located in the front area. Depending on the make and model of your window AC unit, this filter may be disposable. If that’s the case, remove the filter, throw it away and, after you finish cleaning the inside of the unit, replace it with a new one.

More often than not, however, the filter in your window unit will be a washable, reusable one. If that’s the case, pull it out and place it in a space like your sink or bathtub where you’ll be able to let it soak in a mixture of warm water and laundry detergent for half an hour. After that, thoroughly scrub both sides, use clean water to rinse it off, and then set it aside to dry while you finish cleaning the rest of the unit.

Step 5. Back at the filter-less unit, you have another cover to unscrew. It’ll be behind where you took off the front grille and removed the air filter. Once unscrewed, this metal cover can now be pulled up and out. Once this portion is open, it’s time to take the vacuum to your now-empty unit. You want to get up any possible debris that’s gotten inside it’s nooks and crannies.

Step 6. You’ve separated the unit, vacuumed it, and soaked the filter. At this point, you want to take your big bucket and fill it with three gallons of hot-not-boiling water. Add half a cup of bleach and a couple tablespoons of dish soap to the water and stir. Keep wearing your mask at this point, because you don’t want to be inhaling bleach fumes. Once you have your mixture, use your cloths and brushes to scrub every visible corner of your air conditioner. In the hardest-to-clean areas you can leave the solution to sit for a few moments first to make scrubbing it away easier.

Step 7. After that, your unit should be clean and clear of anything, mold or otherwise, that was growing in it. You can replace your filter once it’s dry, put everything back together, and get it plugged back in and cooling you down.

Mold removal from window air conditioner unit might be easier than you thought it was, but it doesn’t make the whole process any less gross. The best way to avoid having to do it again is by transitioning to an air conditioning solution that can take care of your entire home, like central air. If you’d like to learn more about A/C alternatives to the window unit, you can give the team at Welter Heating a call today.