{"id":507,"date":"2019-01-15T07:59:35","date_gmt":"2019-01-15T07:59:35","guid":{"rendered":"https:\/\/smartairfilters.com\/mn\/?p=507"},"modified":"2019-06-01T07:01:17","modified_gmt":"2019-06-01T07:01:17","slug":"wash-clean-hepa","status":"publish","type":"post","link":"https:\/\/smartairfilters.com\/mn\/en\/blog\/wash-clean-hepa\/","title":{"rendered":"Can I Clean or Wash HEPA filters?"},"content":{"rendered":"

HEPA filters are a nearly perfect solution for air pollution. They are backed by\u00a0tons of scientific tests<\/a>; they\u2019re\u00a0pretty cheap<\/a>; they use about as much energy as a lightbulb; they\u00a0even have documented health benefits<\/a>.<\/p>\n

Just about the only remaining problem is that you have to throw out the HEPA filters every few months. So wouldn\u2019t it be great if we could clean them and re-use them? Here we\u2019ll try and answer how to clean HEPA filters.<\/p>\n

 <\/p>\n

People have lots of opinions! On the question-answer site\u00a0Quora, I\u2019ve seen\u00a0people say you can clean HEPA filters by banging the HEPA to get the dust out:<\/p>\n

 <\/p>\n

\"clean<\/p>\n

 <\/p>\n

\u2026or to clean a HEPA filter vacuuming it<\/p>\n

 <\/p>\n

\"clean<\/p>\n

 <\/p>\n

\u2026or even wash it. Then I\u2019ve seen other people say you can NEVER wash a HEPA.<\/p>\n

 <\/p>\n

\"you<\/p>\n

 <\/p>\n

But one thing I haven\u2019t seen is anyone actually test the question. Well now I\u2019ve got data. That\u2019s because\u00a0CK from Smart Air decided to test out the best way to clean a HEPA filter. Here\u2019s CK\u2019s story.<\/p>\n

 <\/p>\n

\"\"<\/p>\n

 <\/p>\n

Vacuuming the HEPA<\/strong><\/h3>\n

First I tried vacuuming a HEPA. I took a dirty HEPA filter, ran tests on its performance, vacuumed it, and then ran more performance tests. In all, I tested 8 dirty HEPAs given to us by avid Smart Air users! They all used in China for between 2-4 months.<\/p>\n

\"\"<\/p>\n

 <\/p>\n

Testing Effectiveness<\/strong><\/h3>\n

Particle Capture:<\/strong>\u00a0I measured the percent of 0.3 micron particles captured at the outlet of the HEPA before and after washing. 0.3 micron particles are a great benchmark because they are the hardest particle size for HEPAs to capture.<\/p>\n

Air Flow:<\/strong>\u00a0I measured air speed coming out of the HEPA before and after washing.<\/p>\n

CADR:\u00a0<\/strong>I used particle capture and air flow to estimate\u00a0CADR<\/a>.<\/p>\n

 <\/p>\n

\"\"<\/p>\n

 <\/p>\n

Vacuum Results<\/strong><\/h3>\n

On average, vacuuming increased relative CADR by about 10%. But there was also a lot of variance, ranging from a 14% increase to a 3% decrease. Based on that data, I\u2019d say cleaning a HEPA by vacuuming it might help a little, but there\u2019s also a decent chance it\u2019ll do nothing at all.<\/p>\n

 <\/p>\n

What\u2019s The Vacuum Doing?<\/strong><\/h3>\n

HEPAs are made of thin fibers. The vacuum is probably pulling out some of the larger dust particles from the HEPA filter, but at the same time some of these fibers as well. You can see what looks like fibers that have been pulled loose in this picture.<\/p>\n

 <\/p>\n

\"HEPA\"<\/p>\n

 <\/p>\n

In short:\u00a0<\/strong>There may be a slight benefit of vacuuming HEPAs, but the benefit is small, and it can also damage\u00a0the HEPA. Therefore, we do not recommend vacuuming.<\/p>\n

\n

<\/h3>\n

Washing the HEPA<\/strong><\/h3>\n

So, what if we wash them instead? I used the same 3 filters that were vacuumed before and washed them under a shower head. Then I gave them a day to dry.<\/p>\n

 <\/p>\n

\"\"<\/p>\n

 <\/p>\n

Washing Results<\/strong><\/h3>\n

I stopped testing after 3 trials because the results were so conclusive: cleaning the HEPA through decreased effectiveness by an average of 32%.<\/p>\n

 <\/p>\n

\"\"<\/strong><\/h3>\n

 <\/p>\n

Why Was Washing So Bad for the HEPAs?<\/strong><\/h3>\n

To get to the bottom of why washing was so bad for the HEPAs, I looked at wind speed and particle capture before and after washing the HEPA.<\/p>\n

First, washing actually increased the windspeed.<\/p>\n

\"\"<\/p>\n

Great, right!? But then particle capture actually\u00a0went down<\/strong>\u00a0a lot after washing.<\/p>\n

 <\/p>\n

\"effectiveness<\/p>\n

Washing the HEPAs probably broke some of the fibers or pushed the gaps between the fibers larger. That would explain why more air passed through after washing, but also more particles!<\/p>\n

In short:\u00a0<\/strong>Washing HEPAs with water breaks down the HEPA material and so is not recommended.<\/p>\n

\n

Bottom Line<\/h3>\n

Vacuuming HEPAs may improve performance, but the effect is small. Washing HEPAs strongly decreases performance. We do not recommend washing HEPAs.<\/p>\n

Based on this data, it seems it really is not possible to clean your HEPA filter. We still recommend replacing your HEPA when its effectiveness drops. When is this? We tested this with the Smart Air\u00a0DIY air purifier<\/a>\u00a0found replacing\u00a0after 140 days<\/a>\u00a0is best. For the larger HEPAs, like those in the\u00a0Blast and Blast Mini purifiers<\/a>\u00a0the huge surface area means they can last over 1 year.<\/p>\n

Own another purifier?\u00a0<\/span>Learn why the standard numbers might not always be accurate<\/a>.<\/p>\n

Open Data<\/strong><\/h3>\n

You can learn more about the testing methods, and view the original data in the\u00a0<\/span>Supplemental Data<\/a>\u00a0<\/span>article.\u00a0<\/span>Click here to learn more<\/a>.<\/p>","protected":false},"excerpt":{"rendered":"

HEPA filters are a nearly perfect solution for air pollution. They are backed by\u00a0tons of scientific tests; they\u2019re\u00a0pretty cheap; they use about as much energy as a lightbulb; they\u00a0even have documented health benefits. Just about the only remaining problem is that you have to throw out the HEPA filters every … Read more<\/a><\/p>\n","protected":false},"author":4580,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-507","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/smartairfilters.com\/mn\/en\/wp-json\/wp\/v2\/posts\/507","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/smartairfilters.com\/mn\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/smartairfilters.com\/mn\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/smartairfilters.com\/mn\/en\/wp-json\/wp\/v2\/users\/4580"}],"replies":[{"embeddable":true,"href":"https:\/\/smartairfilters.com\/mn\/en\/wp-json\/wp\/v2\/comments?post=507"}],"version-history":[{"count":1,"href":"https:\/\/smartairfilters.com\/mn\/en\/wp-json\/wp\/v2\/posts\/507\/revisions"}],"predecessor-version":[{"id":508,"href":"https:\/\/smartairfilters.com\/mn\/en\/wp-json\/wp\/v2\/posts\/507\/revisions\/508"}],"wp:attachment":[{"href":"https:\/\/smartairfilters.com\/mn\/en\/wp-json\/wp\/v2\/media?parent=507"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/smartairfilters.com\/mn\/en\/wp-json\/wp\/v2\/categories?post=507"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/smartairfilters.com\/mn\/en\/wp-json\/wp\/v2\/tags?post=507"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}