Could use another few of these janky 20" window fans upstairs (and maybe some help constructing better frames & mounts).
Planning to purchase some barring a sudden surplus of donations in the interest of immediately relevant (ie, ad-hoc and expedient) ventilation improvements.
tl;dr - got extra fans? Noisebridge might could make good use of them right about now.
estimating that these cheap box fans each can do (very approximately) 1000 cubic feet per minute per fan … So the idea is to have a bunch of these fans blowing out the back upstairs windows in parallel, which is a cheap way to move a few thousand cfm through the upstairs.
upstairs total volume is maybe about 25,000 cubic feet but there is also possibly significant flow of air coming up the back stairs (possibly from the downstairs area if the downstairs interior back door is open and/or even the space next door via the emergency exit). For purposes of back-of-the-envelope calculation, I dunno - might hope for at least 50% airflow coming from upstairs …? Note that the ratio of upstairs/downstairs airflow could be improved by a few additional fans mounted along the upstairs hallway to push air toward the back, and doing whatever work to reduce airflow via the emergency exit (which would require wherewithal with respect to fire safety and building codes).
currently have two fans in the rear windows by the stairs, and there is still another window available for one more fan. So best case for this immediate setup might look something like 3000 cfm total out the back windows vs 25,000 cubic feet upstairs and however much coming along for the ride from downstairs. Not great, not terrible …
downstairs, the main space (containing dirty shop, hackitorium, etc) may or may not get some “fresh” air coming in from Capp street - depending on whether or not the rollup door is open. But I wouldn’t expect much to actually makes it all the way out the back downstairs (where there is just one window that might easily accommodate another fan, also a back door that might could be fitted with a multi-fan frame?)
if the rollup door is shut, then there’s really not much air coming in … so really not a great scenario with regard to potential for airborne contagion if people are spending significant time there.
in any event the 13’ ceilings downstairs translates to approximately 37,000 cubic feet of air which currently has only one way out to the back - via the rear downstairs interior door, if that can be left open. Still, may be possible to engineer an effective “up and out” airflow - if the upstairs output can be increased accordingly.
Along those lines - there has been some scheming to fit one or more of the skylights with fan arrays but please be aware of hard requirement to have written permission from building management for any work involving access to the roof, as per the lease agreement.
Seriously - do not under any circumstances go on the roof without making appropriate arrangements, lest noisebridge get blamed for leaks (already a concern for our nextdoor neighbor).
That said, using some of the skylight apertures for more serious ventilation seems like best option, worth doing sooner rather than later.
Please do not touch the skylights at all. We HAVE to hire professionals for that if we’re going to do it. Please! One we spring a roof leak we are going to be in for a world of hurt.
But, anyway, thanks for setting up the fans and I wonder if we can do the cheap and fast “duct tape air filters to them” solution if we get a lot of smoke this fall from wildfires.
Below is a post by Derek Payton, Founder and Executive Director of Root-Access hacker space in Fresno re using fans to reduce smoke particles:
“In other news, our work with the Central California Asthma Collaborative continues and I sparked a couple of fires at the space on Wednesday. We sealed up the conference room (no air in or out), created some smoke to raise the PM2.5 concentration in the air, and ran various air purifiers for one hour. It is absolutely fascinating to me that a cheap box fan and $20 air filter outperformed every other option. (That Hathaspace purifier is $400!)”
Dan and I spent some time this afternoon building another frame to put a box fan in the far window of the stairwell. Here’s a couple photos he took with my phone:
In case anyone is ever wondering what difference just one or two more people can make in this sort of situation … Thanks!
placed one more in the upstairs hallway today, rounding out this iteration of “the simplest thing that could possibly work” upstairs …
with an air quality measurement device brought in by @lizzard potentially showing results in the upstairs break area towards the back. (Also of note but not pictured here, a caution tape airflow indicator.)
Meanwhile (yesterday) @the department of procurement came through with some significant airflow for the downstairs:
The 24" unit pulling an alleged 7860 cfm in the front …
And a 20" pushing the better part of 6100 cfm out the back: