The more we learn about the health risks of dust mites, bacteria and other indoor air pollutants, the more emphasis is placed on air quality in the home, office and public spaces. HEPA filters are highly effective at removing harmful airborne particles. That’s why they’re used in many air cleaning and ventilation systems that rely on air filtering, such as airplanes, respirators, vacuum cleaners, HVAC systems, air purifiers and more.
If you have HEPA filters in your home, you know they can get pricey, especially if you have to replace numerous filters at once. This leads many of us to wonder if we can clean and reuse a HEPA filter. The answer is yes you can and no you shouldn’t, in many cases. To know when it’s ok and the best way to clean a non-washable HEPA filter if you absolutely have to, read on to learn how HEPA filters work.
What is a HEPA Filter?
A HEPA filter is a high efficiency particulate air (HEPA) filter. HEPA is an official designation for air filters that can remove 99.97% of airborne particles such as dust, dirt, pollen, mold and bacteria that are 0.3 microns (µm) in diameter. For larger and smaller particles, the efficiency rating is even higher.
HEPA filters are made up of randomly arranged, tangled fibers, like tiny hairs, made of a polymer or fiberglass that are designed to catch and trap large and small particles alike. So washing a HEPA filter, whether it’s meant to be cleaned or not, will eventually or immediately damage the fibers and reduce or eliminate their effectiveness.
HEPA filters are available as “permanent”/“washable” and “disposable”/“non-washable”. The fibers on a washable HEPA filter are thicker and made to withstand cleaning with water (with some exceptions). Disposable filters have thinner fibers that are not made to survive the friction of cleaning. Learn more about HEPA filters in The Ultimate HEPA Air Filter Guide.
So there are HEPA filters that are meant to be cleaned and reused. But before learning how to clean them, and the best way to clean non-washable, disposable filters, make sure you know which one you are cleaning first.
How Do I Know if My HEPA Filter is Washable?
If you’re unsure if your HEPA filter is washable or not, remove it and look for the manufacturer’s name and a serial number. You should be able to find out with an online search or call your local hardware store with that information.
First, it’s important to know that some filters use the term ‘HEPA-like’ or something similar but do not actually meet HEPA standards. Read the packaging carefully if someone in your home suffers from allergies or you specifically need the performance of a HEPA filter, like when trying to keep baby nurseries clean.
Second, there are permanent, reusable HEPA filters that are not designed to be cleaned with water. Always follow the manufacturer’s instructions. In general, to clean a washable HEPA filter:
- Make sure the system is powered down before removing the filter.
- Clean the area of the appliance or equipment that houses the filter as much as possible. Also clean the grill or intake port that air flows in through.
- Wash or soak your HEPA filter with warm water and make sure it is completely dry before reinstalling it as any leftover water can lead to mold.
- Check the manufacturer’s instructions as most will not recommend using cleaning agents or drying your HEPA filter in the sun. If in doubt, avoid both.
- Vacuum or follow manufacturer’s instructions for cleaning non-washable permanent HEPA filters.
Permanent HEPA filters should be cleaned every three months and replaced if they appear worn or damaged. You may also need to replace them if your air quality monitor shows more dust, pollen and mold than normal.
An air quality monitor is an essential tool for keeping your family healthy. Check out the best air quality monitor reviews to know what options are out there.
How to Clean and Reuse a Non-Washable HEPA Filter (If You Must)
To be clear, it is not recommended to clean a non-washable HEPA filter. That said, the best and safest way to clean a full HEPA filter is to use your vacuum’s fabric attachment and lightly vacuum it. You may remove some of the bigger and looser particles, but deeply lodged pollutants will likely stay put.
Base the amount of pressure you use on the HEPA filter’s strength and thickness, but do not “scrub” it with the vacuum cleaner. Also, do not clean a non-washable HEPA filter with water as it will damage the fibers or push them apart, making the filter a lot less effective.
HEPA air purifiers recommend replacing disposable HEPA filters to help ensure seamless air quality. If you prefer not to replace filters, an air cleaner may be the right option for you. Learn more about the debate between air cleaner vs. air purifier to decide when and where it makes sense to use one over the other.