Can smoke air purifier kill COVID virus?

Can smoke air purifier kill COVID virus?
4 min read
05 January 2023

Can HEPA filters capture particles as small as coronaviruses?

"The standard requires air filters to remove 99.97 percent of particulate matter greater than or equal to 0.3 microns."

That's a big deal. 0.3 microns is tiny! HEPA filters can capture more than 99 percent of the fine particles that are 200 times thinner than a human hair.

HEPA filter particle capture size 0.3µm; smoke eater machine Coronavirus

Now looking back at the definition of HEPA filters, it seems to refer only to particulate matter greater than or equal to 0.3 microns. What about small particles the size of coronaviruses? Will the HEPA filter catch them?

This question has been the direct result of years of confusion and false claims made by many companies on HEPA filters, so let's cut to the chase and get to the bottom of what's going on.

MSPure smoke eater machine

Why are our intuitions about filters wrong

The answer, surprisingly, is that our intuition about the filter is inaccurate. Most people, including me, think that the HEPA is a net, and if the particles are smaller than the holes in the net, they will be missed. It makes sense, doesn't it?

HEPA filters - do they capture particles like a net?

This intuition is fine for larger particles, which get stuck as they fly through the HEPA filter.

But when we have very fine particles like coronaviruses, that's not the case. It turns out that particles as small as the coronavirus and other nanoparticles are captured through a scientific phenomenon called diffusion.

Learn more about the science behind diffusion, and how it traps nanoparticles

Diffusion is very effective at capturing small molecules the size of viruses. According to NASA, the HEPA filter "captures particles almost 100 percent of the time."

NASA proposed that HEPA filters capture nanoparticles

An experiment at the University of Minnesota, using fiberglass filters as a medium, found that fiberglass filters were "close to HEPA's ability to capture small particles," meaning that they should perform as well as HEPA filters. Silver particles ranging from 3 to 20 nanometers (3 to 20 times smaller than coronavirus particles) were shot at the strainer medium.

HEPA filter captures nanoparticles; smoke eater machines catch coronavirus

The results show that 99.99% of the particles smaller than 5 nanometers can be captured by the filter. HEPA filters (and even lower level filters, like furnace filters) are very effective at catching smaller particles, like coronaviruses!

What does this mean for the coronavirus?

If you live in an average house, or if you work in an office or school with a large number of employees, turning on your smoke eater machine can help filter out any virus-sized particles in the air, potentially reducing the chance of transmission. A single HEPA filter filters out 99 percent of the coronavirus.

Bottom line: Can smoke eater machines catch coronavirus?

The air purifier with HEPA filters or lower grade filters can trap solid particles of almost any size, including particles as small as 0.1 micron in diameter -- or the same size as coronavirus.

If you live in a shared house or work in an enclosed environment with lots of people around, turning on an smoke eater machine can help reduce the spread of coronavirus.

For places with central air conditioning systems, make sure they include filters and are well maintained. If your central air-conditioning system doesn't have a strainer, installing smoke eater machines in every room can still help reduce the spread of the virus.

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huang luis 2
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