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Comment by EnderWT | Hacker News Reader

On the first point in the article, there is a definition for HEPA which for ISO is 99.95% efficiency. The Ikea purifier doesn't meet this. It meets the EPA standard, hence the designation of E12 (99.5%).

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As noted by the sibling comment, the parent comment mischaracterizes TFA's reference to "true-HEPA." It also makes the same hash of characterizing standards as the affiliate blogspam. Read TFA, which has an interesting characterization of the tradeoffs involved and not this comment.

The article didn't say HEPA has no definition. It said that 'true-HEPA' has no definition.

Which seems intentionally nitpicky given that "HEPA" is defined and the Ikea one doesn't meet it while the others do. Therefore, "true-HEPA" almost certainly just means "HEPA", and the "true" just means "is actually HEPA" not some other special definition.

The rest of the article's points are good, but this one comes across as just axe grinding.

Yeah. I'd assumed that 'true-HEPA' was a made-up term intended to trick people into thinking something is HEPA when it's actually worse. But that doesn't seem to be the case.

The Wikipedia HEPA article[1] says it's actually a reaction to people doing that -- some companies advertise "HEPA-type" or "HEPA-style", and so companies with actual HEPA filters market them as "True HEPA". It's a race to the bottom.

[1] https://en.wikipedia.org/wiki/HEPA#Marketing

A little further into the article, it explains why this doesn't make any difference.

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