How To Clean A Hepa Filter

Can you lot clean a HEPA filter? If so, how should you lot launder or clean a HEPA filter?

These questions keep cropping upward, equally they're just about the only remaining problem for HEPA filters.

HEPA filters are nigh perfect: they are backed by tons of scientific tests; they're pretty cheap; they use about as much energy equally a lightbulb; and they fifty-fifty have documented health benefits. Just replacing them every bit opposed to washing them isn't ideal. It would be great if we can clean and wash and re-apply HEPA filters.

Some 'Experts' Say You Tin can Clean HEPA Filters

On the question-reply site Quora, I've seen industry insiders say y'all tin clean HEPA filters past banging the HEPA filter to get the grit out:

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

Some people fifty-fifty say yous can clean HEPA filters by vacuuming them:

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

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

HEPA filters should not be washed but replaced

But ane thing I haven't seen is anyone actually exam the question and present the data. To get to the lesser of whether we 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 you lot search for "how to clean HEPA filter," you volition see ii methods to make 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. Nosotros took a dirty HEPA filter, ran tests on its performance before cleaning, vacuumed it, and then ran more than operation tests after cleaning it. In all, 8 dirty HEPAs which had been used for 3-4 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 out the performance increase or decrease in the HEPA filter earlier and after cleaning. CK tested:

Particle Capture: To meet how cleaning the HEPA filter impacted capture functioning, the percentage of 0.3 micron particles by the HEPA was measured before and afterwards cleaning. 0.3 micron particles are a great benchmark because they are the hardest particle size for HEPAs to capture.
Air Flow: The amount of air traveling through the HEPA filter before and after cleaning tin 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 'aureate standard' for measuring an air purifier's performance. It measured the total combined bear upon (particle capture + air flow) of washing on the HEPA filter

Here's how the 8 HEPA filters that were vacuumed performed before and subsequently cleaning:

Effects of vacuuming HEPA filter on its performance and clean efficiency

Should Y'all Vacuum HEPA Filters: Results

On average, vacuuming increased CADR by virtually 10%. But there was also a lot of variance, ranging from a 14% increase to a 3% decrease. Based on that data, cleaning a HEPA by vacuuming might aid a footling, simply in that location's also a decent chance information technology'll do nothing at all, or information technology could even damage your filter.

What's The Vacuum Doing to the HEPA Filter?

HEPAs are fabricated of thin fibers. The vacuum is probably pulling out some of the larger dust particles from the HEPA filter, just at the aforementioned time some of these fibers as well. You tin run into what looks like fibers that have been pulled loose in this flick.

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

Vacuuming bottom line:There may be a slight benefit of vacuuming HEPAs, but the benefit is pocket-size, and information technology can also damage the HEPA. Therefore, we do not recommend vacuuming.

ii. Cleaning HEPA filters by Washing With H2o

Vacuuming did very trivial to meliorate the HEPA filters' effectiveness. And so, how almost washing HEPA filters instead? This time, CK tested 3 HEPA filters by washing them nether a shower head (with water simply) and and then leaving them to dry for a twenty-four hours.

Should You Launder HEPA Filters With H2o: Results

I stopped testing after 3 trials because the results were and then conclusive: washing HEPA filters with h2o decreased effectiveness by an average of 32%.

Why Is It Bad to Wash HEPA Filters?

To go to the bottom of why washing was and then bad for the HEPAs, I looked at current of air speed and particle capture before and later on 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, correct!? But and so the particle capture of the HEPA filter actually went down a lot later 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 broke some of the fibers or made the gaps between the fibers larger. That would explain why more air passed through after washing, merely also more particles!

Washing bottom line:Washing HEPA filters with water significantly decreases operation.

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

Vacuuming HEPAs may improve operation, simply the effect is minor.
Washing HEPAs strongly decreases performance. We practice not recommend washing HEPAs.

Therefore, HEPA filters should still exist replaced when information technology starts to get clogged and its effectiveness dropped. When is this? Learn why the standard numbers might non e'er be accurate.

Smart Air

Washing & Cleaning HEPA Filters: Open Data

Y'all tin can learn more almost the testing methods and view the original information in the supplemental data commodity.

How I Protect Myself

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