Post B2gdDBAMWfsoudiw2C by jefftk@mastodon.mit.edu
 (DIR) More posts by jefftk@mastodon.mit.edu
 (DIR) Post #B2gdD4b2x44KXN9e9g by jefftk@mastodon.mit.edu
       2026-01-26T19:13:41Z
       
       1 likes, 1 repeats
       
       Do I know anyone who wants a far-UVC lamp?  Some friends of mine are giving away a bunch, if you'd actually use it: https://aerodrop.org
       
 (DIR) Post #B2gdDBAMWfsoudiw2C by jefftk@mastodon.mit.edu
       2026-01-26T19:14:32Z
       
       0 likes, 0 repeats
       
       More context on this tech: https://faruvc.org
       
 (DIR) Post #B2geGBgd9CFZLjobpo by cjd@pkteerium.xyz
       2026-01-26T19:46:03.104082Z
       
       0 likes, 0 repeats
       
       This is really cool.Can you generate far-UVC with an LED?How cheap do you imagine these can become in the long term?Can lights be made which emit UV and also visible light - something that can be retro-fitted into existing light fixtures?Is regular UV cheaper? (I assume so)  Is there a reason not to use regular UV in places like train stations where people spend limited time?Nice project!
       
 (DIR) Post #B2gfwUyztWWJJR95o8 by jefftk@mastodon.mit.edu
       2026-01-26T20:00:22Z
       
       1 likes, 0 repeats
       
       @cjd The ideal placement for regular light and far-UVC is different, so integrating them into the same fixture isn't ideal.
       
 (DIR) Post #B2gfxfZK1QMEQwh7QG by jefftk@mastodon.mit.edu
       2026-01-26T19:59:43Z
       
       1 likes, 0 repeats
       
       @cjd 222nm AlGaN LEDs do exist, but they're super low output.  There are some decent prototypes at 226nm, and then commercial ones in the 230-235nm range.  Unfortunately, risk to people goes up a *lot* as you increase wavelength, so I'm not currently convinced that any commercially available UVC LED is "far" enough to be safe to shine on humans.
       
 (DIR) Post #B2gg0DH1g9bTXxLjqC by jefftk@mastodon.mit.edu
       2026-01-26T20:05:16Z
       
       1 likes, 0 repeats
       
       @cjd Regular 254nm UVC, basically a standard (mercury vapor) fluorescent light with the fluorescent coating left off and UV-transparent glass, is indeed way cheaper.  But it's also not safe to shine on humans, even for relatively short times.Now, it's still a great option for air cleaning, especially in spaces with high ceilings, but you need to position it carefully so it's shining upwards and not on people.
       
 (DIR) Post #B2gg5WEwacQLoluDlw by cjd@pkteerium.xyz
       2026-01-26T20:06:37.348643Z
       
       0 likes, 0 repeats
       
       I guess that's something people do in air handlers, and (if I'm not mistaken) bug zappers (?)Is Far UVC the wavelength selected for UV blood irradiation?
       
 (DIR) Post #B2iFPZiL4d99wDuiiO by jefftk@mastodon.mit.edu
       2026-01-27T14:10:59Z
       
       1 likes, 0 repeats
       
       @cjd I hadn't previously heard of UV blood irradiation, but looking into it now it looks like that's all longer wavelengths.