I hadn't seen that study, thanks for sharing! I've added it to faruvc.org, and added a warning that people shouldn't consider 233nm LED sources as equivalent to 222nm KrCl sources.

Sorry this took me so long to fix, but it should work now! https://faruvc.org, https://www.far-uvc.org, and https://far-uvc.org should all redirect to https://www.faruvc.org.

(https://www.faruvc.org is hosted on GitHub pages, and I'd tried to use my DNS registrars redirect system to point the others there.  This doesn't work, though, because it only uses HTTP.  They could totally make HTTPS work, via LetsEncrypt, but they haven't.  So instead I needed to point those three aliases at the same VPS that serves https://www.jefftk.com , make that VPS get the certs, and then make that VPS redirect them to the canonical site.  Possibly there was a better way to do it, but this is working now.)

There are very few providers, and hardly any of them sell an off-the-shelf product. You usually can’t just buy a lamp to try it out—you have to call the company, get a consultation, and often have someone from the company come install the lamp. It’s a lot of overhead for an expensive product that most people have never heard of.

This has changed! You can buy an Aerolamp for $500. I have one for my own use, and my dance organization uses four.

money is disproportionately held by people who are high up in the company, who I would guess are more selfish than average which means lower donations

My guess would go the other way:

• A lot of the early employees and higher-ups have EA-ish perspectives (ex: one of the Amodeis joined GWWC in 2010; the other is married to Holden Karnofsky), and I'd expect this fraction to decrease as you get into more recent employees.

• Each additional dollar you have gives a decreasing impact via improving your lifestyle. I've become substantially less selfish percentage-wise as my net worth has increased.

I don't know much about hypochlorous acid fogging; it sounds like it would be corrosive, and probably at least somewhat bad for people?

For air pollution yes, but far-UVC should still work on mold.

Glycol vapors are generally going to be cheaper, but they're less far along. There isn't a product you can buy that will maintain your space at the right concentration. The closest you can get would be Bleu Garde (formerly Grignard Pure) but they're not actually selling their product.

I'd recommend playing around with Illuminate. Depending on the room size and shape, far-UVC can range from mildly less effective as a good air purifier on high to far more effective.

For example, lets say you have an Aerolamp in the corner of a tiny room (10ft x 7ft x 8ft). You'd need to dim the lamp to 70% to protect people who are near the corner. Illuminate calculates (guv) a CADR-equivalent for a range of pathogens, and taking the median I get 216 CFM. Then let's say you instead put it in a cavernous room (50ft x 50ft x 50ft). Now you can easily run it on full power (guv) and I get a median CADR-UV of 1,979 CFM. Even if you run it at 70% power to keep it apples-to-apples the median CADR-UV is still 1,354 CFM. (sheet) Of course most rooms will be well between these two extremes!

Compare to the AirFanta 3Pro at 413 CFM on high (though it's noisy enough on high that I only run mine that high if I need to clear smoke).

there's a cluster of advice I get from folksinger people that... seems totally "correct", but, feels... insufficiently ambitious or something. 

The advice includes things like "try to have people come in singing on the chorus, and not worry so much about the verses". Or "teach people the song beforehand" and "hold practice singalongs before the event or send out music so people can learn it", or "teach people music."

My guess is that the problem is if you're getting advice from people who are in communities where it's uncommon to get large groups of people we're singing is not central to their identity unfamiliar songs. So they don't have a very relevant advice! Instead I would look for material aimed at religious leaders, camp counselors, and teachers. (But I have no idea if there is good advice out there, or if this is one of the many categories where the people who are good at it have not passed on their wisdom, and in many cases don't even realize there could add it.)

try to have people come in singing on the chorus, and not worry so much about the verses

I think this is just massively obsolete, and dates back to people singing along without being able to read lyrics. Either because you didn't have printing, or people weren't (sufficiently) literate.

(Though there are also communities that intentionally don't involve written words in there folk singing, such as pub singers, which I do think can be a nice aesthetic. If that's what you're doing, then the format where someone sings the versus solo and everyone joins in on the chorus works well.)