Can You Clean Hepa Filters

Can y'all clean a HEPA filter? If so, how should you wash or clean a HEPA filter?

These questions proceed cropping upwardly, every bit they're just about the merely remaining problem for HEPA filters.

HEPA filters are well-nigh perfect: they are backed by tons of scientific tests; they're pretty inexpensive; they use most equally much energy as a lightbulb; and they fifty-fifty have documented wellness benefits. But replacing them equally opposed to washing them isn't platonic. It would exist dandy if we can clean and wash and re-use HEPA filters.

Some 'Experts' Say You Tin Make clean HEPA Filters

On the question-answer site Quora, I've seen industry insiders say you can clean HEPA filters by banging the HEPA filter to get the dust out:

Expert explains you can clean a HEPA filter by banging out dust

Some people even say you can clean HEPA filters by vacuuming them:

Suggestions that we should use a vacuum cleaner to clean a HEPA filter

…or even past washing HEPA filters with h2o. Yet other experts say you lot tin can NEVER clean HEPA filters.

HEPA filters should not be washed but replaced

But one affair I haven't seen is anyone actually test the question and present the data. To go to the bottom of whether nosotros should make clean HEPA filters, and the best way to clean them, Smart Air engineer CK tested washing and cleaning HEPA filters in the Smart Air lab.

Smart Air engineer CK testing washing and cleaning HEPA filters

When y'all search for "how to clean HEPA filter," you will see ii methods to clean HEPA filters: vacuuming and washing. Smart Air put both of these to the test.

1. Cleaning HEPA filters by Vacuuming

The first test we tried was vacuuming HEPA filters. We took a dirty HEPA filter, ran tests on its performance before cleaning, vacuumed it, and and then ran more operation tests after cleaning information technology. In all, eight dirty HEPAs which had been used for iii-4 months in Beijing air were tested.

vacuuming HEPA filters to remove clogged dirt and reuse them

Testing Effectiveness of Vacuumed HEPA Filters

For each cleaning method, CK ran 3 types of tests to measure the performance increase or decrease in the HEPA filter before and later on cleaning. CK tested:

Particle Capture: To see how cleaning the HEPA filter impacted capture performance, the percentage of 0.3 micron particles by the HEPA was measured before and afterward cleaning. 0.three micron particles are a great benchmark considering they are the hardest particle size for HEPAs to capture.
Air Menses: The corporeality of air traveling through the HEPA filter earlier and later cleaning tin can tell us if the HEPA filter is less clogged, or if the fibers in the HEPA filter have been damaged due to washing.
CADR: CADR is the 'gold standard' for measuring an air purifier'due south performance. It measured the total combined bear on (particle capture + air flow) of washing on the HEPA filter

Here's how the eight HEPA filters that were vacuumed performed before and afterwards cleaning:

Effects of vacuuming HEPA filter on its performance and clean efficiency

Should You lot Vacuum HEPA Filters: Results

On average, vacuuming increased CADR by about x%. Only there was besides a lot of variance, ranging from a 14% increment to a 3% decrease. Based on that data, cleaning a HEPA by vacuuming might help a little, but there's also a decent hazard it'll do zero at all, or it could even damage your filter.

What's The Vacuum Doing to the HEPA Filter?

HEPAs are made of thin fibers. The vacuum is probably pulling out some of the larger dust particles from the HEPA filter, merely at the same time some of these fibers as well. You lot tin can see what looks like fibers that have been pulled loose in this film.

vacuuming HEPA filter can remove clogged dust particles but also damage fibers

Vacuuming bottom line:In that location may exist a slight benefit of vacuuming HEPAs, just the do good is small, and it can besides damage the HEPA. Therefore, we do not recommend vacuuming.

ii. Cleaning HEPA filters by Washing With Water

Vacuuming did very little to ameliorate the HEPA filters' effectiveness. So, how about washing HEPA filters instead? This time, CK tested 3 HEPA filters past washing them under a shower head (with water only) and and then leaving them to dry out for a day.

Should You Wash HEPA Filters With H2o: Results

I stopped testing after 3 trials because the results were so conclusive: washing HEPA filters with water decreased effectiveness by an average of 32%.

Why Is It Bad to Wash HEPA Filters?

To go to the bottom of why washing was so bad for the HEPAs, I looked at air current speed and particle capture before and afterwards washing.

First, washing actually increased the amount of air passing through the HEPA filter.

Washing a HEPA filter can improve the airflow through the filter, but may still damage or destroy the HEPA filter

Great, right!? Simply so the particle capture of the HEPA filter actually went downward a lot afterward washing.

The number of particles captured by the HEPA filter after washing dropped drastically due to the water damaging the filter

Washing the HEPA filters probably bankrupt some of the fibers or fabricated the gaps between the fibers larger. That would explain why more air passed through after washing, but besides more than particles!

Washing bottom line:Washing HEPA filters with h2o significantly decreases performance.

Bottom Line: How to Clean and Wash a HEPA Filter?

Vacuuming HEPAs may meliorate operation, but the consequence is minor.
Washing HEPAs strongly decreases performance. We do not recommend washing HEPAs.

Therefore, HEPA filters should still be replaced when information technology starts to get clogged and its effectiveness dropped. When is this? Learn why the standard numbers might not always exist accurate.

Smart Air

Washing & Cleaning HEPA Filters: Open Data

Yous tin learn more about the testing methods and view the original data in the supplemental data article.

How I Protect Myself

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