10
Air Cleaners Don’t Stop You Getting Sick, Research Shows
(www.uea.ac.uk)
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
this post was submitted on 21 Nov 2023
10 points (85.7% liked)
Science
16735 readers
24 users here now
Subscribe to see new publications and popular science coverage of current research on your homepage
founded 6 years ago
MODERATORS
So why don’t they work?
This paper points out the filtration of SARS-CoV-2 isn't clear cut whatsoever. Papers stating it could be filtered from the air all demonstrated to have publication bias. The thing about viruses is they are super tiny. On average, a virus is 10x smaller than a bacterial cell. This makes filtration much more difficult to accomplish.
The study found the most effective methods for air purification were germicidal lights, ionisers, and electrostatic cleaners. With HEPA specifically, the filters can snag objects as small as 0.3μm. However, the largest viruses are 500nm or 0.5μm in diameter. Based on the numbers, HEPA filtration is capable of removing the largest viruses from the air, but that's a small minority of all viruses. SARS-CoV-2 comes in somewhere between 60nm/0.06μm to 140nm/0.14μm in diameter, meaning HEPA filtration can not remove it from the air.
I was taught μm stands for micrometers, which are 1,000 times smaller than millimeters. Nanometers(nm) are 1,000 times smaller than micrometers(μm), which means nanometers are CRAZY small!
That’s what I was wondering. Like not that it can’t work but that it wasn’t implemented at the sufficient scale to do what it is purported to do.
At a guess, it doesn't matter how clean the air coming out of the HVAC system is if you're sitting near or talking with someone who's sick.