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Your air conditioner is full of mold and bugs—here's how to clean it

It can get gross in there

A person holding up two air conditioner filters. The left filter is dirty and the right is clean. Credit: amixstudio / iStock via Getty Images Plus

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Wherever you find water, you find life. Unfortunately, this life can be mildew, mold, bacteria, and insects in your home and air conditioning space. You probably know that you need to clean your shower curtain, your washing machine, and your sponges when they get wet. However, did you know that your air conditioner is a breeding ground for all sorts of nastiness?

Your AC creates condensation, which can harbor disease, insects, and mold. Here’s how to keep your window AC unit and portable AC units clean and running more efficiently.

How often should you clean your air conditioner?

A hand reaches into frame to clean the grill on the back of the A/C with a cloth.
Credit: Reviewed / Jonathan Chan

Always unplug the unit before working on it to avoid accidental shocks.

At a minimum, you should clean your AC unit at the beginning and end of each season to properly maintain it. Doing so helps remove any built-up mold or mildew and helps prevent it from happening again.

You should also clean your air filter whenever your unit smells bad. If the odor persists, then you should move to clean the interior. This will keep it running better in the long run.

What you'll need

A box of baking soda sits near the removed A/C filter.
Credit: Reviewed / Jonathan Chan

A combination of baking soda and water can help eliminate odors from the filter.

  • An air conditioner
  • Vinegar
  • Baking soda
  • Two washcloths
  • Screwdriver

How to clean your air conditioner

An A/C is sitting on its side, with its casing fully removed and sitting beside it.
Credit: Reviewed / Jonathan Chan

Always unplug the unit before working on it to avoid accidental shocks.

Step 1: Unplug it

Turning off the power might be enough. Unplug the unit to avoid getting shocked while cleaning.

Step 2: Remove and clean the filter

In most window AC units or outdoor units, your filter is located at the front. Most of the time, they slide or snap off.

Gently vacuum the screen with your vacuum's dusting brush to remove dust and debris. If you detect any odor, run a mixture of baking soda and water over the screen. You can use a spray bottle for this.

Do not put the filter in the dishwasher: It can damage the fine mesh. If your AC uses a carbon filter, it will be destroyed.

Step 3: Remove the casing.

Most of the mold and mildew grow inside the air conditioning unit, where it's much less likely to get cleaned away. You'll need to remove the outer casing to access this hiding spot. Four or five screws typically hold the casing together. If you’re hunting down that last screw, try removing the front panel.

Step 4: Mop up any excess water.

After removing the casing, you'll be greeted by a maze of tubes. The place we want to focus on is towards the front of the unit, which is called the evaporator. This is where any dripping noises come from because water drains into a pan at the base of the unit.

Mop up any standing moisture to help prevent mold from developing, then wipe down the tubes and pan. Use a mixture of water and vinegar to help kill microbes.

Step 5: Dust off the fans.

Your air conditioner has fans in the front and back. If either fan collects too much dust, it will have issues circulating the air properly. This can reduce airflow and possibly reduce the lifespan of your device. A quick dusting with a fin comb or microfiber cloth will do the trick here.

Product image of Air Conditioner Fin Comb
Air Conditioner Fin Comb

Use this comb to help make cleaning ACs a breeze.

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Step 6: Wipe down the condenser coils.

You can use the same vinegar mix to clean the tubes behind the aluminum fins in the back of the unit. They also make dedicated coil cleaner for air conditioning coils.

These air conditioner coils are called condenser coils, and they help remove heat from the air inside your home. The build-up of dust, dirt, and debris here means the AC will operate less efficiently. This can waste a lot of energy. If you ever feel your AC isn't cooling like it used to, it's possible that cleaning the dirty coils is the fix.

Product image of Coil Cleaner for AC Unit
Coil Cleaner for AC Unit

It's fast-acting and effective at removing build-up on all air conditioning units.

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Step 7: Put everything back together again.

Turn on the unit for a while to dry everything off. The air coming out should smell fresh and clean.

Now that your unit is clean, you can enjoy your clean, cool air with all the peace of mind that a confirmed bug-free AC can offer.

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