The air purifier market is riddled with false marketing claims bordering with fraud. I wanted to buy a purifier once but after doing some research I become so d

The air purifier market is riddled with false marketing claims bordering with fraud. I wanted to buy a purifier once but after doing some research I become so disillusioned that I abandoned the idea. Some of the problems I found: * If the filter is not true HEPA it is probably a garbage. Beware any HPP or HEPA-like nonsense. * If the filter is no-maintenance it is not filtering anything. * Check the price of the replacement filters first, it is the same business model as with printer cartridges. * The square feet or square meter characteristic is meaningless/arbitrary, you need to know the air volume per time. * Whatever "Allergy Association" certificates are probably meaningless marketing. * Pre-filter makes sense - it prevents hair and bugs from clogging the HEPA filter. Any other type of filter is probably garbage, there is usually no data or metrics for efficiency. * The typical carbon filter is probably totally useless, you would need a solid quantity of carbon to absorb anything, not just carbon film or fibres. * The efficiency of the UV lamp for killing viruses and bacteria is questionable, at best. The germicidal effect is a function of the correct wavelength, dose and exposure time. No data as usual. * The ionised air and ozone may be bad for you and there is no data or metrics on how much ions/ozone you get. To add insult to injury most of the purifiers look as if they were designed in the 80's and will blemish every room. I will invoke the Gell-Mann Amnesia effect - if a company misleads you with a film-like carbon filter, what is the chance they are telling the truth about the HEPA filter, the flow rate or the noise level?