How to Clean A HEPA Filter

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Updated February 2, 2023

If you are shopping for the best air purifier, you have likely noticed that a large majority of them feature HEPA air filters. Can these popular filters be cleaned? For the short answer, most likely. First, unplug the device from the outlet and remove the filter. Next, vacuum both sides of the filter using a brush attachment. Rinse the filter with cold water to remove any lingering dust particles or dirt. Let the filter fully dry before reinstalling it into the air purifier. Simple, right?

However, there are times when a HEPA filter can be washed and reused, and times when it can’t. But, it depends on the air cleaner model. Most in part because the filtration may be affected if the filter isn’t a washable filter. You’re likely to do more damage to the filter. 

KEY TAKEAWAYS:

  • HEPA filters can remove more than 99 percent of airborne pollutants as long as they are above 0.3 microns in diameter.
  • Most HEPA filters must be disposed of and replaced every six months to one year, though the length may vary depending on usage and related factors.
  • Some HEPA filters can be cleaned by using a handheld vacuum on its lowest setting or by placing it under cold tap water.

HEPA stands for high-efficiency air particulate air filter. HEPA is more of an industry standard than an actual type, as they still come in various shapes and sizes. However, in order to be classified as a true HEPA filter, it must be able to filtrate at least 99.97 percent of impurities from the air as long as they are above 0.3 microns in diameter.

Having an air cleaning device that can filter at this level means better indoor air quality. Usually, this means performance from stronger types of filters. 

HEPA filters are made from a large range of materials, including “coarse glass fibers, coated animal hair, vegetable fibers, synthetic fibers (such as polyester or nylon), synthetic foams, metallic wools, or expanded metals and foils,” according to the EPA. They’re great for homes, and some models can even work in cars.

Insider Tip

In order to be classified as a true HEPA filter, it must be able to filtrate at least 99.97 percent of impurities from the air as long as they are above 0.3 microns in diameter.

Can You Clean a HEPA Filter?

In some cases, you cannot clean a HEPA filter, due to the fragile materials they are comprised of. Instead, dispose of and replace a true HEPA filter once every six months to a year.

You can, however, clean your air purifier blades and clean your air purifier filter to assist in long-term maintenance.

How to Clean a HEPA Filter

Instead of purchasing a new HEPA filter, there are times when cleaning and reinserting the existing one is possible. If the HEPA filter inside your air purifier is specifically labeled as washable or permanent, you should be able to clean it. Note that sometimes even when the HEPA filter is appropriately cleaned, your device may not trap particles as well as it did before. 

Typically, this comes about if the filter has been damaged from cleaning. You want to avoid using water and try a low-suction vacuum cleaner to clean the HEPA filter. 

Make sure you don’t need to replace it. Otherwise, your air purifier won’t help with flu, and it won’t help with pet allergies, either.

You should still exercise caution when cleaning. Below are some tips to consider.

Read the Instructions

If you have a HEPA filter that can be cleaned and reinserted, head to your air purifier’s instruction manual for details. Each washable HEPA filter may necessitate different cleaning processes, so you will want to ensure you do the right thing. Some filters can only be vacuumed, for instance, and not placed in or around water. The instructions should lay everything out for you. If it does not, feel free to contact the manufacturer for more details via email, a phone call, or a social network.

You don’t want to use water to wash a filter because excess water trapped in the filter can damage the air purifier. Damaging your device is worse than having a few dirty filters to replace. 

STAT: A HEPA filter consists of tightly woven fibers, and washing or scrubbing it is likely to affect the condition of the fibers, which in turn makes the filter less effective at cleaning 99%+ of microscopic particles. (source)

What’s more, avoid touching the filter if the user manual says not to wash it. This means it’s a non-washable filter and shouldn’t be cleaned at all. Instead, you’ll want to trash it and replace it with a brand-new filter. 

Sure, the cost of replacement filters is what drives the price up for air purifiers, but it’s better to use disposable filters for a non-washable HEPA filter. However, if you’re on a budget, opt for a filter you can wash and reuse. 

Insider Tip

HEPA filters are made from a large range of materials, including “coarse glass fibers, coated animal hair, vegetable fibers, synthetic fibers (such as polyester or nylon), synthetic foams, metallic wools, or expanded metals and foils,” according to the EPA.

Vacuum Gently

You may be able to vacuum the exterior of a HEPA filter, though you should do so on a low setting in a gentle manner. We recommend using a handheld vacuum on its lowest setting to suck away obvious dirt and debris. Do not overdo it. Give it a single pass, and then reinsert it back into the air purifier. If you vacuum a HEPA filter too harshly, it will damage the internal layers, and it will not purify air properly.

Use Cold Water

A washable HEPA filter should be washed under a gentle stream of cold water for 30 seconds or so. Take great care to avoid touching any of the filter fibers, as that could cause unnecessary damage. Once you are satisfied that the filter has been thoroughly washed, leave it out to dry for 30 minutes or so before placing it back into the air purifier. Some HEPA filters will have to be left out to dry for 24 hours or more, so read the instructions for details. Do not use a blow dryer on the filter or leave it out in the sun to dry, as both of these steps could cause damage.

Warning

In most cases, you cannot clean a HEPA filter, due to the fragile materials they are comprised of.

Wear a Mask

The HEPA filter is what traps all of the various impurities from the air. In other words, you will want to avoid breathing in anything that has become stuck inside this filter. You can protect yourself by wearing a good mask as you clean. Even splashing a HEPA filter with water could dislodge and pollutants into the atmosphere. You should wear a mask whenever you are handling a used HEPA filter, even when you are simply disposing of it.

F.A.Q.

Why might cleaning a HEPA filter be a bad idea?

The HEPA filter is what holds all of the filtered pollutants that have been collected. Cleaning it can dislodge these air particles and could also damage the filter itself.


What’s the vacuum doing to the HEPA filter?

A vacuum can easily damage a HEPA filter, as the air suction will force the filter’s fibers into awkward positions, breaking the theme in many cases.


Is there any filter better than HEPA?

HEPA is the current industry standard, though “better” may simply be a matter of perspective. HEPA filters are not that great at removing volatile organic compounds (VOCs), for instance, as they tend to be smaller than 0.3 microns in diameter.


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