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.
If you place the lamps so they’re only above people’s heads you can use 254nm bulbs, which are much cheaper (they’re essentially standard fluorescent lights with UV-transparent glass and no phosphor). People have done this for a long time in places like TB wards, but you do need to be pretty careful about placement to ensure your 254nm UV really is only shining in the space above.
An upper-room 254nm system with the required expert installation is not going to be cheap or accessible. The bulbs are cheap—the systems are not, because the safety margins are much tighter.
You can use 222nm lamps as an upper-room system just fine—you can set it up yourself without worrying too much about overexposure. A lot of people do just because it’s simpler to stick the lamp on a high bookshelf instead of mounting it on a swivel head and tilting it downward. It works fine! Makes the system a bit more dependent on vertical air currents to work well but the efficacy hit is pretty minor. There aren’t zero risks but I sure prefer it to a 254nm overexposure.
(Disclosure: I am a cofounder and part-owner of Aerolamp)
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.
If safety is a concern for such sources, is it worth considering placing the lights so they mostly shine on the space above people’s heads?
If you place the lamps so they’re only above people’s heads you can use 254nm bulbs, which are much cheaper (they’re essentially standard fluorescent lights with UV-transparent glass and no phosphor). People have done this for a long time in places like TB wards, but you do need to be pretty careful about placement to ensure your 254nm UV really is only shining in the space above.
An upper-room 254nm system with the required expert installation is not going to be cheap or accessible. The bulbs are cheap—the systems are not, because the safety margins are much tighter.
You can use 222nm lamps as an upper-room system just fine—you can set it up yourself without worrying too much about overexposure. A lot of people do just because it’s simpler to stick the lamp on a high bookshelf instead of mounting it on a swivel head and tilting it downward. It works fine! Makes the system a bit more dependent on vertical air currents to work well but the efficacy hit is pretty minor. There aren’t zero risks but I sure prefer it to a 254nm overexposure.
(Disclosure: I am a cofounder and part-owner of Aerolamp)