How to Clean an Air Conditioner (Because You Should Be Doing It on the Reg)

how to clean an air conditioner cat

Air conditioning is a gift from the gods—without it we’d all suffer many sleepless nights and miserable sweaty days during the summer months. Alas, like all appliances, air conditioners will let you down hard if you don’t perform the necessary upkeep. Fortunately, A/C maintenance is remarkably manageable. We spoke to Glenn Wiseman, sales manager of Top Hat Home Comfort Services, and got the full scoop on how to clean an air conditioner—you know, so it keeps on keepin’ on for many summers to come.

Why Do I Have to Clean My Air Conditioner Filter?

Every type of air conditioner is equipped with a filter that protects the unit by cleaning the air that circulates through it. Over time, the filter will naturally become clogged with the particles it’s been busy removing from the air—and that’s when it’s time to give it a good clean. In fact, if you neglect the filter, the accumulated dirt will ultimately block the flow of cold air, making your air conditioner less effective and forcing you to run it on full blast just to feel, well, anything at all. (Hint: That’s very bad news for your energy bill.) In other words, don’t assume your air conditioner is kaput just because its performance isn’t up to snuff—a nice clean filter is often all it takes to resolve the issue. Read on for everything you need to know about air conditioner filters.

How to Clean Central A/C Unit Filters

Some central air conditioning units and HVAC units have disposable filters that simply need to be replaced, while others have washable filters that you can scrub down at home. In the former instance, you’ll want to open up the vents of the air conditioner and inspect the filters every one to two months, swapping ‘em out for a brand new filter as soon as they start to look gross. Washable filters should be checked just as often, dusted off, and thoroughly washed whenever there’s visible build-up. Fortunately, the process for washing an air conditioner filter is fairly straightforward. Here’s what to do:

1. Using a screwdriver, open up all the vents of the air conditioner unit and remove the filters. (Note: Many units have more than one filter, and you’re going to want to clean them all.)

2. If the filter looks pretty OK, good on you—that means you’ve been doing this process regularly. Regardless, you’re going to want to vacuum each filter so as to avoid a more serious scrub down in the future. A dirt devil or a regular vacuum with a hose attachment are both good choices here.

3. Once you’ve sucked up the loose debris with your vacuum, it’s time to reassess the filter. If no stubborn build-up remains, you’re free to return the filters to the unit and move on with your day. Not so lucky? Move on to the next step.

4. To wash an air conditioning filter, simply soak it in a solution of one part water and one part white vinegar for up to an hour.

5. After the filter has soaked for a bit, rinse the filter with fresh water.

6. Finally, air dry the filter thoroughly and return it to the air conditioning unit.

How to Clean a Window A/C Unit Filter

The steps for cleaning the filter of a window air conditioning unit are much the same as the ones described above, but here’s the breakdown.

1. Open up the vent and remove the filter. (Typically, no tools are required for this.)

2. Remove loose dust from the filter, either with a vacuum cleaner (hose attachment) or by wiping it with a microfiber cloth.

3. Soak the filter in a solution of equal parts warm water and white vinegar.

4. Rinse the filter with fresh water.

5. Air dry the filter thoroughly and return it to the unit.

How to Clean A/C coils

The evaporator and condenser coils of an air conditioner are responsible for pushing hot air outside, which means they’re pretty important, since heat transfer is the modus operandi of an A/C unit. As you might have guessed, the coils are also prone to getting dirty, so it’s a good idea to clean them occasionally. In central air conditioning units, a professional should take care of the evaporator coils. The outdoor condenser, however, is easy to access and can be maintained with a yearly hosing down. This will clear any debris that may have accumulated on the exterior fins—just be sure to turn the unit off first and keep water away from the electrical source.

The coils of a window air conditioning unit should also be cleaned annually. See below for a step-by-step guide.

1. Turn off the unit and open it up; remove the filter—and maybe clean it while you’re at it.

2. Behind the filter you’ll see aluminum fins. This is the evaporator coil. Grab a (dry) toothbrush and gently comb the fins to remove any debris. Don’t get too aggressive, though, as you might damage the fins; if they bend out of place during the process, carefully bend them back.

3. Finally, use a can of condensed air to spray the inside of the unit. This will remove dust from the coils, so you can really go to town here.

4. Reassemble the unit and enjoy the fruits of your labor (i.e., a frosty home).

General Air Conditioner Maintenance Tips

  • Store your window A/C during the winter months to protect it from the elements—just be sure to thoroughly clean it before you put it away.
  • Wash or replace the filter every one to two months.
  • Never return a washed filter to the unit before it has dried completely; a damp filter can cause mold growth within the unit.
  • Clean the coils one to four times per year with condensed air and a toothbrush for window units, or a hose for the outdoor condenser of a central A/C unit.


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Freelance PureWow Editor

Emma Singer is a freelance contributing editor and writer at PureWow who has over 7 years of professional proofreading, copyediting and writing experience. At PureWow, she covers...