To add to this, hepa filters are extremely effective. They are rated at something like 99.95%. That is the rating for the size of particle that they are worst a

To add to this, hepa filters are extremely effective. They are rated at something like 99.95%. That is the rating for the size of particle that they are worst at filtering. Particles both smaller and larger are filtered at a higher rate. This is also only for air passing through the filter once, if you have a air purifier running in a small room it will pass all the air through it multiple times, completely cleaning the air of basically anything that is not gas or vapour. Of course new particles can come into the air from various sources. It’s kinda magical that we can have this technology that is affordable and actually genuinely does what is advertised They are so effective that they will literally filter a bad smell out of a room assuming it’s not a gas that’s making then smell.