Replacing vs. Cleaning HEPA Filters: What's the Best Choice?

[Ulysees]

Is it enough to just blow a HEPA filter with high-pressure compressed air, instead of replacing it?

 

[Ulysees]

In other words, do microbes get blown away?

 

[Moonbear]

That would defeat the entire purpose of having used a HEPA filter if you just blew everything back into the air, wouldn't it?

I'm not sure how HEPA filters actually work, though, so can't tell you if there's a way to clean them and reuse them, or if they must be disposed of every time they get dirty. The engineers might know more about this in their applications, so I'm going to move this thread over to engineering and see if you get a better answer there.

 

[Ulysees]

Alright.

Btw, the idea is to blow the filter outside.

 

[Ulysees]

Which I've already done.

 

[berkeman]

In other words, do microbes get blown away?

I don't think you will get much cleaning efficiency by trying to blow the captured particles and microbes back out. Part of how the HEPA filter works is that it traps and embeds the particles -- they don't just get lightly stuck on the outer surface of the outermost fibers:

http://en.wikipedia.org/wiki/HEPA_filter

I know I sure wouldn't want to use a HEPA mask that somebody had used before, and tried to clean with compressed air. They're disposable for a reason.

 

[Ulysees]

Thank you berkeman.

 

[Ulysees]

What if you wash the filter, with a strong detergent or whatever?

 

[berkeman]

What if you wash the filter, with a strong detergent or whatever?

My guess is that if you try to clean these disposable HEPA masks with something strong enough to get rid of the particles and microbes, that you will also compromise the tiny fibre structures that do the filtering.

 

[russ_watters]

Also, what kind of hepa filter are we talking about here? Oftentimes, residential grade filters may say they are hepa, but they really aren't. Ie, a real hepa filter (such as a bag filter) wouldn't be cleanable with compressed air. What I'm guessing you are dealing with is just a very good regular pleated media filter.

 

[hxtasy]

My guess is that if you try to clean these disposable HEPA masks with something strong enough to get rid of the particles and microbes, that you will also compromise the tiny fibre structures that do the filtering.

This is probably the most important reason not to mess with the HEPA filter. I think you need to know a lot more about the HEPA system before you try to use detergents on it as well. They are kind of expensive, so i see your reasoning to clean them. but as efficient as they are, i would personally just buy another one than chance it. Also keep in mind that a slightly used filter sometimes works better, some trapt dirt pieces will actually trap other dirt pieces.