I've written up a more accessible version of the technique I use to perform at-home CADR tests in a test chamber. My current setup is a bit more advanced, it is automated and runs from a raspberry pi. Otherwise, it's the same.
#AirFilterDev
https://t.co/6OIGVv1L8x
@open_erv I still don’t understand. Couldn’t you look at the realtime spectrum (from the microphone) and figure out the contribution of the motor noise by estimating its frequency? As long as it’s different enough from the fan noise freq, that should work.
@open_erv Not sure what you mean about needing a dynamic microphone connected to an oscope. Have you tried a phone app like AudioTools RTA or REW on a PC? I have a process for using REW on PC with a dayton audio UMM-6.
@alvelda@mryoung151 What reason is there to be confident in the IFR? I recall covid initially being thought to have a high IFR, which ended up not being the case.
@JeromeAdamsMD@_CatintheHat@cleanairkits we’ve come up with innovative purifiers based on PC fans and the Corsi-Rosenthal box’s familiar furnace filters to achieve designs with >300 cfm CADR at <40 dBA (they’re quiet).
@JeromeAdamsMD@_CatintheHat The Dyson TP0x models are around 90 cfm CADR. It would add about 2 ACH to a standard size living room, falling short of the CDC recommended 5+ ACH.
@ArbyCalzony I’m being conservative. There can be a drop going from 1900 -> 2500, depending on the fans and filter area. https://t.co/aVYGOR2Ru2
Also, my experimental method has improved so I really ought to look at those old results again.
We have "one more thing" this week, a super value to keep families safer just in time for Thanksgiving holidays. Introducing the Brisk Box, a $129 taped CR box kit of 6 SickleFlow fans in precision-cut corrugated panels producing up to 300 cfm: https://t.co/Zicd2kHttu
@ParentMishmash A CR box would be preferable. It’s hard for the fan to push air through the unpleated fabric therefore the CADR of this solution will be much, much lower than if furnace filters were used with the same fan.
@VentiloAngel@dannyashton@Engineer_Wong The better way to measure wattage with the cheap meters (kill-a-watt included) is over the course of several hours. I have found that those measurements give the same result as averaging 60s or so of instantaneous measurements, but ymmv.
@VentiloAngel@dannyashton@Engineer_Wong I have had a unit with 2 A14 iPPC-3000 running off a 1A supply for 2 years. I think the problem might be something other than the max amps of the supply. Is it 12V?
@VentiloAngel@dannyashton@Engineer_Wong ime the rated amps are for the spike at startup and the draw while running is much lower. You can almost certainly run 4 of those with 2A.
@VentiloAngel Cool, like I said, should see no difference. Our filter guards have a very coarse mesh. Can use something like speaker mesh and it still barely impacts cadr.