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.
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
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.
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-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