News for hackers. Stuff that matters.

A comment on Dyson air purifier outperformed by cheap DIY box fan filter in Marketplace test. Parent comment

Re:Dyson air purifier outperformed by cheap DIY box fan filt... by Bakary on Thursday February 11, 2021 @01:03PM (#26104955)
You have to make sure the filter is HEPA, and calculate whether the device has had the time to do a full air change given the room size and its CADR rating.

Viruses are generally too small for even the best filters, but the droplets that carry them are well within what a HEPA filter can manage.

[ Parent | on HN ]
Re:Dyson air purifier outperformed by cheap DIY box fan filt... by Maursault on Sunday February 14, 2021 @03:53PM (#26136157)
> Viruses are generally too small for even the best filters...

The average diameter of coronavirus particles is around 0.12 μm. The diameter of the envelope is 0.08 μm and the spikes are 0.02 μm long.

A P100 HEPA filter will remove as much as 99.97% (for P95 it is 95%) of all airborne particulates with an aerodynamic diameter of 0.3 μm, and particles both larger and smaller are removed with an efficiency greater than 99.97%.

Even if viruses are smaller than 0.3 μm, they are an easy target for HEPA filters.

[ Parent | on HN ]