Comment by tssva

Regarding the section about whether it is or isn't a true HEPA filter, the Wirecutter is a US based website targeting mostly US based consumers so maybe we should look at the major US standard regarding HEPA filters which is DOE-STD-3020-2015. This standard was originally developed to cover HEPA filters supplied by DOE contractors in nuclear facilities.

How does it define a HEPA filter? "High Efficiency Particulate Air (HEPA) Filter: A throwaway, extended-medium, dry type filter with a rigid casing enclosing the full depth of the pleats. The filter shall exhibit a minimum efficiency of 99.97% when tested with an aerosol of 0.3 micrometer diameter."

So according to the standard in the target market for the review the IKEA air purifier does not use a true HEPA filter and the recommended unit does.

Edit: I looked closer at the European specification used in the article. By that specification the filter in the IKEA unit also is not a true HEPA filter but an EPA filter. The Exx designations mean it is a EPA filter and the Hxx designations mean a HEPA filter.