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I just want to point out that the HEPA ratings are pretty lax on how much and what they are effectively cleaning in the air. Pretty much everybody can use the w

I just want to point out that the HEPA ratings are pretty lax on how much and what they are effectively cleaning in the air. Pretty much everybody can use the word HEPA and it not mean that much if they are, for example, using an ionizer that essentially just makes the particles 'sticky' while putting them back in the air. Source: I work at a top international air purification company.

stephenbez 10y ago
Thanks. Do you have any recommendations on what to look for when buying a filter? I was planning on buying a filter labelled True HEPA from a well known company, that uses a fan and not ionization, and being sure to replace the filter as directed. The HEPA standard, ensures PM0.3 are filtered out. But this article (http://now.tufts.edu/articles/big-road-blues-pollution-highways http://now.tufts.edu/articles/big-road-blues-pollution-highw...) says ultrafine particles (PM0.1) are the biggest health risk. Do you know if any filters remove ultrafine particles? Wikipedia seems to suggest that most do: "Diffusion predominates below the 0.1 μm diameter particle size. Impaction and interception predominate above 0.4 μm. In between, near the most penetrating particle size (MPPS) 0.3 μm, both diffusion and interception are comparatively inefficient. Because this is the weakest point in the filter's performance, the HEPA specifications use the retention of these particles to classify the filter" https://en.wikipedia.org/wiki/HEPA https://en.wikipedia.org/wiki/HEPA
- memonkey 10y ago
  It is pretty difficult to filter out ultra fine particles anyway and some of the best air purifiers can claim to do a lot. Obviously, you will be breathing that stuff every day and unless the air around you is seriously affecting your health, you don't need a high end air purifier. This is my opinion, but unless you have allergies or asthma, most top of the line air filtration systems won't have much of an impact on your day to day and I would personally suggest any $250-$500 range air purifier. This content in this article[1] does a really good job at comparing air purifiers but they suggest an ionizer which can have negative effects. Things to look out for: - No ionizer. - No uv light. - True HEPA is fine but if they've trademarked or registered their HEPA brand (HyperHEPA, HEPASilent), I would ask them more about what that means and they should provide a pretty good answer within the context. 1. http://thesweethome.com/reviews/best-air-purifier/ http://thesweethome.com/reviews/best-air-purifier/
  - chillwaves 10y ago
    Why no UV? Seems like it couldn't hurt.
yourapostasy 10y ago
If we cannot rely upon HEPA ratings, then what should consumers look for if we want to take air purification seriously? Short of going out to purchase industrial air purification equipment that is purpose-made for applications like clean rooms, I don't know how to evaluate and purchase for a residential application. There are lots of pollen allergy patients who would be very happy if they could live in a PassivHaus that can be made practically airtight and pass all incoming air and circulating through an actually effective air purification system.

stephenbez 10y ago

Thanks. Do you have any recommendations on what to look for when buying a filter? I was planning on buying a filter labelled True HEPA from a well known company, that uses a fan and not ionization, and being sure to replace the filter as directed. The HEPA standard, ensures PM0.3 are filtered out. But this article (http://now.tufts.edu/articles/big-road-blues-pollution-highways http://now.tufts.edu/articles/big-road-blues-pollution-highw...) says ultrafine particles (PM0.1) are the biggest health risk. Do you know if any filters remove ultrafine particles? Wikipedia seems to suggest that most do: "Diffusion predominates below the 0.1 μm diameter particle size. Impaction and interception predominate above 0.4 μm. In between, near the most penetrating particle size (MPPS) 0.3 μm, both diffusion and interception are comparatively inefficient. Because this is the weakest point in the filter's performance, the HEPA specifications use the retention of these particles to classify the filter" https://en.wikipedia.org/wiki/HEPA https://en.wikipedia.org/wiki/HEPA

memonkey 10y ago
It is pretty difficult to filter out ultra fine particles anyway and some of the best air purifiers can claim to do a lot. Obviously, you will be breathing that stuff every day and unless the air around you is seriously affecting your health, you don't need a high end air purifier. This is my opinion, but unless you have allergies or asthma, most top of the line air filtration systems won't have much of an impact on your day to day and I would personally suggest any $250-$500 range air purifier. This content in this article[1] does a really good job at comparing air purifiers but they suggest an ionizer which can have negative effects. Things to look out for: - No ionizer. - No uv light. - True HEPA is fine but if they've trademarked or registered their HEPA brand (HyperHEPA, HEPASilent), I would ask them more about what that means and they should provide a pretty good answer within the context. 1. http://thesweethome.com/reviews/best-air-purifier/ http://thesweethome.com/reviews/best-air-purifier/
- chillwaves 10y ago
  Why no UV? Seems like it couldn't hurt.

yourapostasy 10y ago

If we cannot rely upon HEPA ratings, then what should consumers look for if we want to take air purification seriously? Short of going out to purchase industrial air purification equipment that is purpose-made for applications like clean rooms, I don't know how to evaluate and purchase for a residential application. There are lots of pollen allergy patients who would be very happy if they could live in a PassivHaus that can be made practically airtight and pass all incoming air and circulating through an actually effective air purification system.