Comment by amluto
3 years ago
Multiplying .9005 and .90005 by 10000 does not actually cause a 10x difference to appear. No, really, try it!
If your goal is to play with numbers, you could raise them both to a large power. You would discover that the ratio between them increases exponentially, but this would pale in comparison to the fact that both results would exponentially approach zero much faster than the ratio would increase.
10000 x .9005 is 9,005. 10000 x .90005 is 9,000.5.
Meaning that the first filter left 5 particles vs the second filter leaving .5 particles.
A 10x difference.
The goal isn't to "play with numbers" but to understand why/if the relative effectiveness of a filter results in a substantive difference in air quality.
The data shows it does.
> The data shows it does
As I described above [1] the data show that the difference between 70% and 99.95% matters, not that the difference between 99.5% and 99.95% does. (And that's ignoring difference in flow rates, which is also very large.)
[1] https://news.ycombinator.com/item?id=31823047
The 70% and 99.95% difference is because of the 10x filtration efficiency difference, combined with the CADR difference.
This is very straight-forward.
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Extraordinary claims require extraordinary evidence. The data shows a huge difference which cannot be explained by the difference between 5 particles and 0.5 particles.
As noted in the article, the Wirecutter does not explain its methodology or give particularly complete data, and what explanations they do give about filtration make no sense.
It's a 10x difference in filtration efficiency, combined with a CADR difference between the two units.
I don't understand why you think more of an explanation is required?
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