[avian]

> it provides a static pressure of 7.63 mmH2O

If anyone else is wondering, that's about 0.8 mbar (roughly 8 ten-thousands of an atmosphere), or 80 Pa of over-pressure.

To put this into perspective, my local atmospheric pressure varied about 2000 Pa in the last 48h due to weather changes.

[labawi]

IMO, absolute pressure doesn't give much of a perspective.

Car tire pressure is about 1.8-2.5 Bar.

Your 2000 Pa atmospheric pressure change is about 20 mBar.

Pressure in an inflated balloon is about 2 mBar (0.002 Bar).

Noctua's static pressure is 0.8 mBar. Let's call it 0.5 mBar dynamic working pressure.

Not as low as I expected. Not sure if it will have a semi-reasonable speed, but that will definitely push some air.

Another comparison, 0.5 mBar is 50 Pa = 50 N/m². That gives about 50 * 0.3 * 0.3 / 10 ~ 0.5 kg force on a 30x30 cm² surface.

Finally, as the article video and data shows, it does actually work.

[1] http://scipp.ucsc.edu/outreach/balloon/labs/InflationExp.htm

[avian]

That balloon figure doesn’t make sense to me in relation to atmospheric pressure changes. It would mean that a tied-off balloon would randomly inflate and deflate itself depending on weather.

[labawi]

It does, slightly. Pressure change 20 mBar = 2% of absolute atmospheric pressure -> about 2% balloon volume change, with corresponding 2% internal absolute pressure change, while keeping the same low differential inside-outside pressure.

[wlesieutre]

Lemme go send my air intake through a time machine and as long as the weather keeps changing we can use that to drive air through a filter!

[avian]

No need for a time machine (or being snarky - I did say it's just for comparison, didn't I? I think it does put the "very high pressure" into perspective)

That said, your time machine idea could be simply implemented with a large, airtight box. Simply put the filter over it and weather changes will push and pull air through the filter with two orders of magnitude more pressure than this little fan. Volume of filtered air will depend on the volume of the box though, so better get a large one.

[thatguy0900]

If you had a time machine you might as well just skip the filter and pull in air from before the industrial revolution directly