Comment by addicted
3 years ago
In all it’s bluster, this article forgets to add the fact that the Wirecutter actually tested the IKEA device, and didn’t just go by theoretical specs.
> Tim tested the Förnuftig in his 200-square-foot spare room, using the methods described above. But rather than focusing on its performance on 0.3-micron particles, he noted how well it removed 3-micron particles from the air. (IKEA confirmed that this was the appropriate size to look at; it’s the closest to PM2.5 that our TSI AeroTrak particle counter can measure separately.) The Förnuftig disappointed, even when we considered that the test room was larger than the machine is meant for, as it removed just 85.2% of 3-micron particles in 30 minutes on high and 73.6% in 30 minutes on medium. Its performance on 0.3-micron particles was, as expected, worse: 64.5% removed on high and 53.5% on medium. Compared with our budget/small-space pick, the Levoit Core 300, which removed 97.4% and 92.6%, respectively, of 0.3-micron particles and virtually all 3-micron particles on the same settings, that’s very poor.
Errr direct quote from the article: "These tests… are not credible.
Take the 3.0-micron tests on medium, where Wirecutter claims “virtually all” particles were removed. If we take that to mean 99%, that implies a CADR of 236.2. (The math is below.) That is 75% higher than the manufacturer’s claimed performance on high.
It also contradicts the Wirecutter’s own tests. On a different page, they tested the same purifier on medium in a (smaller) 1215 ft³ room and found only 92% of particles were removed. This implies a (plausible) CADR of just 98.1.
So we can either (a) accept that the purifier’s performance randomly varies by a factor of more than 2.4 or (b) conclude that the Wirecutter did an extremely shoddy job of running these tests."
Why did you make three separate top level comments on this?
There's a whole section on the Wirecutter's tests, called "On tests."
This is somewhat addressed in paragraph about steady state.