Comment by elil17
9 hours ago
The advantage of far UVC over other UV air cleaning solutions is that it doesn't need to be ducted. This means that you can kill microbes right when they leave someone's mouth - you don't need to wait for them to be sucked through an air handler.
I'm curious if plastics embrittlement is a problem with Far-UVC. I recently was putting a large evaporative humidifier [1] through its paces for someone to get my opinion, and a challenge was that you had to clean the water tank that was the foundation of the unit fairly frequently (every few days). I provided feedback to the manufacturer that a far UVC bulb in the tank might be useful for reducing cleaning intervals.
For use cases where the emissions are contained (HVAC, water tanks, etc), I think it's a slam dunk from an electronic antiseptic perspective. UV is somewhat common in water filtration today, but perhaps an improvement is possible if these bulbs last longer than existing UV solutions.
[1] https://levoit.com/collections/humidifiers-diffusers/product...
(I do not recommend the humidifier by the way, simply too much work to keep the water tank and the evaporation panels clean, I recommend an ultrasonic version instead)
I do not believe that there is a good understanding of the impact of far-uvc on plastic embrittlement.
Delightful, an experiment to be run!
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Along the same lines… where is the proof that as the unit ages it doesn’t leave the magic 220nm range?
It is complete nonsense to point this at people.
Here's a paper: https://www.jstage.jst.go.jp/article/lsj/50/7/50_394/_pdf
This is a study of the Ushio Care222 unit, but its underlying physics is the same as any other KrCl excimer lamp, so its pretty implausible for other KrCl lamps to exhibit spectral drift when this one doesn't.
The spectrum does change a bit over time--it actually gets less dangerous. But it's a very slight difference.
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It doesn't have to be, but you can avoid any concerns about looking into it or affecting the light quality in the room by doing so.
If you were going to duct it then why wouldn't you just use regular UVC? Much cheaper.
Fair point.