4 ms·
>If you only use 99% it means there are small particles you can't catch. Air filters don't work like sieves. The smallest particles are easier to block than th
by mrob 2mo ago
>If you only use 99% it means there are small particles you can't catch.
Air filters don't work like sieves. The smallest particles are easier to block than the mid-sized particles. See:
https://en.wikipedia.org/wiki/Mechanical_filter_(respirator) https://en.wikipedia.org/wiki/Mechanical_filter_(respirator)
Clean Air Delivery Rate is often specified for specific pollutants. One is smoke, which is mostly small particles.
- OroPla 2mo agoI am specifically talking about particles in the 0.3 to 1.0 micron range which according to the graph from your link are the most difficult to filter out. Can a 99% filter catch these? My understanding of this is that they cannot. According to hepacart [1] 99% HEPA filters do not even exist, since HEPA seems to be clearly defined: > HEPA filter definition, which requires a filtration efficiency of 99.97% for particles as small as 0.3 microns. "HEPA-type" filters may capture larger particles but are not effective against the finer particulates that true HEPA filters excel at removing. [1] https://www.hepacart.com/blog/dont-be-fooled-by-hepa-filter-types-standard-and-approved-filters https://www.hepacart.com/blog/dont-be-fooled-by-hepa-filter-...