The Case Against Using a HEPA Filter News & Opinion

The Case Against Using a HEPA Filter

Everyone knows that using a HEPA filter is the way to go all the time, right? After gathering information from several manufacturers, we’re going to make the case against using a HEPA filter. At least most of the time. Think we’re crazy? That’s okay. That’s okay, but by the time we get to the end of the article, I’m hoping you’ll see things our way.


What is a HEPA Filter?

The Case Against Using a HEPA Filter

Here’s the 30-second breakdown:

  • HEPA stands for High-Efficiency Particulate Air
  • The filter is a mesh design that’s simply finer than other filters
  • HEPA filters capture 99.97% of all particles 0.3 microns or larger
  • HEPA filters trap things like concrete dust, pollen, dander, and other small particulates that many people don’t want to breathe
  • You’ll find them in dust extractors, vacuums, HVAC systems, and more where trapping the most particles possible is key

The Case Against Using a HEPA Filter

The case against using a HEPA filter surrounds its design. The characteristics that make it so good at trapping particles also hinders it.

Take your typical cellulose (paper) filter. You get 99.9% trapping of particles 2 microns or larger. That’s a pretty close trapping percentage (just 0.07% less effective), but the particles that are nearly 7x as big can pass through. We’re still just talking 2 microns, though. That’s 1/500 of a millimeter.

The Case Against Using a HEPA Filter
Which one’s which? You might be able to tell by looking them, but one will give you better vacuum performance and the other will trap more particles.

The extra space in the filter does more than just let somewhat larger particles though, it also allows more air to pass. Because of that, going with a non-HEPA filter increases the performance of your vacuum or dust extractor more than if you use HEPA.

Here’s the other thing – because HEPA filters trap more, they also clog more quickly. That means you’ll see performance drop more quickly and have to replace it more often.

And let’s not forget the cost. Take Bosch’s dust extractor filters for example. The HEPA filter will run you right at $100 while the cellulose filter is just $30. You can buy three cellulose filters for every HEPA filter you buy and still have $10 leftover to take your wife out for ice cream. That’s a win.


Sometimes You Need a HEPA Filter

There are absolutely applications when you need a HEPA filter on site. It just might not be as often as you expect.

Pro Tip: No matter what filter you’re using, but especially when you’re going with the extra cost of HEPA, use a fleece collection bag. It acts as a pre-filter and extends the life of your filter.

The Bottom Line

HEPA filters are better at trapping particles than standard ones and capture much smaller ones. The trade-off is that your performance suffers and HEPA filters cost more while being replaced more often. So use a HEPA filter when it’s required, but save yourself some money and keep your dust extractor running more efficiently when you don’t.

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Frank Anthony

Hi Kenny,
How many layers of the cellulose filter media would equal the filtration of an N95 respirator?
I have my wifes family overseas and as you probably know those items are in short supply. I was thinking that there has to be some filter media stock that can be used to provide some protection since there are no other available options. THanks

David S

The numbers in the comparisons and your statements following them are a little confusing, so I’m not sure if I read and understood them correctly. You state that a HEPA filter traps 99.97% of particles 3 microns or larger, whereas a standard paper filter traps 99.9% of particles 2 microns or larger. It’s obvious that 99.97% is better than 99.9%, but as stated in the article, a HEPA filter traps particles as small as 3 microns, and the standard paper filter traps particles as small as 2 microns. If my math is correct, isn’t 2 microns smaller than 3 microns?… Read more »