where can i find more info on how far uvc compares to air purifiers? is it vastly more effective, or merely quieter? the website touches on it only very briefly.
Hard to answer this question because there's a tradeoff between noise, airflow, and surface area with air purifiers. Eg if you cover your ceiling with air filters, the noise will be minimal.
I'd say if you have enough output power and are only limited by uv exposure, it's vastly more effective. I had to buy a couple of expensive Clean Air Kits purifiers to get ~25 air changes per hour in a smallish room, but 100+ equivalent ACH is possible with far-UVC, either by using light filtered to 222nm or keeping it in some kind of ceiling louver that traps the light. Not sure how the cost compares though, as they seem to be limited by output power / $ rather than safety limits.
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).
I'd also be interested in a comparison with chemicals like propylene glycol with respect to biohardening public spaces.
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.
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.)
I thought the diagram was very helpful. It looks like the integral of intensity and depth of live skin cells is about an order of magnitude higher for 254 nm (inexpensive and efficient mercury discharge). So you're saying that the fact that far UVC is more strongly absorbed in the first 10 microns, that makes the inactivation rate of bacteria and viruses higher?
I wanted to link an explanation of how far-UVC works, why you might want to use it to clean indoor air, and what we know about its safety. I didn't find anything I liked, so I made something:
faruvc.org.You can also link it as
far-uvc.org; I got both domains since the hyphenated one reads better but is a bit longer.Let me know if you have ideas for making it better! My goal is to have something anyone can understand, without simplifying so much that it's misleading.
At some point I'd like to include an illustration showing far-UVC in use in an occupied space, but I don't have one I like right now.
(While I'm an employee of SecureBio, this is a personal project.)
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