Awesome write up. Isn't this similar to how N95 masks are rated, as well? That is, the mask will stop 95% of the particles at its worst size (if my understandi

Awesome write up. Isn't this similar to how N95 masks are rated, as well? That is, the mask will stop 95% of the particles at its worst size (if my understanding is correct). HEPA is a much better filter than N95. Also, it's my understanding that CV itself can't exist in the atmosphere itself, but must be contained in a droplet. (Again, I'm hoping this is correct). If this is true, then it's not about the size of CV, but the range of sizes of water droplets. Perhaps also the drying effect on droplets caught in a filter, which cause the CV 'death' is true? Doesn't this mean that the whole argument now degrades to probabilities of a CV droplet getting through and causing a sickness? 1. How many CV exist in a droplet? 2. How many droplets must one encounter to have a good chance of being exposed? 3. How many CV does it take for a person to get sick? (Presuming the immune system will be a factor in eradicating some particles?) There are other factors of course, the main one would be is how quickly the air in a room is scrubbed by the filter itself. If the air flow is too low, the filter would be as good as useless, because it's not trapping anything.