How to Clean Your Air Conditioner's Filter for Better Health

Study up so you can keep cool without catching a cold.

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The average American spends a whopping 90% of the day indoors, according to estimates from the U.S. Environmental Protection Agency (EPA). While that might be better to reduce sun-related skin damage, it's less than ideal for our lungs and overall well-being. Not only is outdoor air a boon for mental health, but it's also much cleaner. The EPA reports that pollen, animal allergens, mold spores, ozone, pesticides and other contaminants can swirl around inside, making some indoor pollutants two to five times higher indoors than outdoors.

Unfortunately, it's not always possible to keep your windows open for a breath of fresh air. Whether it's due to seasonal allergies (keeping windows closed is one of the biggest pro tips if you suffer from seasonal sniffles) or because of a steamy heat wave, most homes in the U.S. turn to—and turn on—their air conditioners a good portion of the year.

A hand holding a vacuum hose over an air conditioner filter
Getty Images / DonNichols / nanthm

But how often do you think of cleaning your air conditioner, in particular, its filter? Much like the dishwasher filter, we admit to often overlooking this feature that drastically impacts the AC's efficiency (hi, sky-high electricity bill!) and our indoor air quality.

Read on for the dirty details about your air filter, plus how to keep it squeaky-clean so you can prevent potential colds or breathing difficulties.

What Does an Air Filter Do, Exactly?

An air conditioner filter is designed to collect dust and debris that's in your home's atmosphere. It can withstand some accumulation over time, but once the filter is full of gunk, the impurities have nowhere else to go but back into the air. If your air filter is overloaded, you might notice more dust or dirt on normally-clean surfaces—even soon after dusting or mopping. You or your roommates may notice an increase in allergy or asthma symptoms or even potentially colds due to more mold, pollen or other pollutants circulating around the home.

How to Clean an Air Conditioner Filter

Whether you have a whole-home HVAC system or a window unit (see this TikTok cleaning hack for a how-to guide for the latter!), it likely has a filter.

Aim to clean your filter every one to three months; you'll probably need to do so more if you don't own a separate air purifier or do have pets in your home.

As with any appliance cleaning task, review the manufacturer instructions to confirm the best air filter technique. Some units should be replaced completely rather than cleaned, so check the product manual or website for these details.

If you have an air conditioner filter that's created to be cleaned and reused, follow these steps:

1. Turn it off.

Before opening your air conditioner, flip the machine "off." Then carefully open the unit, remove the filter and inspect it for build-up. (Note that some units have multiple filters; if so, check them all.) If you notice any excess debris or dust, proceed. Otherwise, slip it back in, put the unit back together and set a reminder to check again in one month.

Tip: If your air filter displays any distinct signs of damage, such as holes, tears or gunk that won't budge, it's time to replace it with a new air filter.

2. Suck it up.

Using the hose attachment on your vacuum cleaner (we love this Shark Navigator Lift-Away Professional Upright Vacuum; buy it: $127.46, Amazon) or a handheld vacuum (like VacLife Handheld Vacuum; buy it: $50, Amazon), gently brush over the air filter to suck up as much dust and grime as possible. While your vacuum is handy, give any air vents a dust-up. A tool like Swiffer Dusters Heavy-Duty Extendable Handle Dusting Kit (buy it: $7.99 for four, Target) can help if the vacuum hose doesn't reach.

If it's now looking clean, slip the filter back in, replace the cover and set a reminder to check again in one month. If not, move on to the final step.

3. Wash it out.

For a super deep clean—as long as your manual says it's okay—soak the filter for one hour in a sink filled 50:50 with water and white vinegar. Rinse the air filter with fresh water, allow it to dry completely, which should take about 30 minutes; this will help prevent any mold issues. Replace the filter and cover, take note of the cleaning date, then set a reminder to clean or change the filter accordingly based on the manufacturer's specifications.

Now that your air filter is tidy and in tip-top shape, keep the clean routine going. Check out 6 filthy places in your kitchen you should be cleaning every day.

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