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Comment by rootlocus

3 years ago

Consider a purifier that purifies 99.995%. According to your "probabilities", that's a 100x improvement. Now consider this purifier purifies 1 cubic millimeter of air per hour. That is to say, each hour 1 cubic millimeter of air is 99.995% purified (no probability). Would you say that this purifier is 100x better than the IKEA one with 99.5% purification at 1 cubic feet of air per minute? Considering air flow is not a trick.

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rootlocus

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etchalon  3 years ago

A E12 filter filters out 99.5% of particles above 0.3 microns.

An H13 filter filters out 99.95% of particles above 0.3 microns.

Assuming a volume of 10000 particles above 0.3 microns:

An E12 filter will leave 50 particles.

An H13 filter will leave 5 particles.

The "rootlocus" filter would leave 0.5 particles.

So yes, I would say your filter is 100x better because it literally is.

  • rootlocus  3 years ago

    > Assuming a volume of 10000 particles above 0.3 microns:

    That volume is not the same volume processed by all filters in the same amount of time.

    In the first minute:

        E12  filters 10000 particles   @ 99.5% performance   -> removes 9950,   leaves 50
    H13  filters 10000 particles   @ 99.95% performance  -> removes 9995,   leaves 5
    RLv1 filters 10 particles      @ 99.995% performance -> removes 10,     leaves 0
    RLv2 filters 1000000 particles @ 99% performance     -> removes 990000, leaves 10000

    RLv1 only filters a tiny amount of air each minute, while RLv2 filters a lot of air each minute (I've improved the flow, but drastically botched the performance)

    By your method, RLv2 is 2000x slower than H13, but in the same ammount of time filtered 99x more particles. RLv1 needs to run 99000 minutes to filter the same amount of particles RLv2 does in one minute.

    The example is meant to show air flow totaly dominates performance, and it's not "a trick" to multiply by it. I also want to point out that comparing the amount of particles "left" (50 vs 5 vs 0 vs 10000) is nonsense and absolutely no indication of performance in any way.

    • hexane360  3 years ago

      In other words: you miss 100% of the particles you don't circulate

      (With apologies to Wayne Gretzky)