vbelenky

7 ms·

1.
by vbelenky 8mo ago
Sure, I'm game! I can loop you into our comms with LLA and you can do the same, and they can send us both the results as they come in. OSLUV says they're happy to pay for it too so no worries about the expense I really do think th
2.
by vbelenky 8mo ago
Here is a paper showing that the USHIO care222 module achieves an L70 of at least 10,000 hours: https://www.jstage.jst.go.jp/article/lsj/50/7/50_394/_pdf Here is a poster with more data in the same
3.
by vbelenky 8mo ago
This is incorrect, unless by "old school" UVC lights you mean 172nm xenon lamps. Those produce quite a lot of ozone. 254nm UVC lamps (also quite old school) do not produce ozone. Ozone is produced at wavelengths below 242nm, but a
4.
by vbelenky 8mo ago
The tear layer only contributes a little bit--far-UV eye safety is mostly down to the fact that the 222nm only penetrates to outer epithelium (so cells that will be dead in a few days anyway), and the fact that your eyes get very little eff
5.
by vbelenky 8mo ago
Yeah, what responsibly deployed far-UV is definitely not is an instant kill beam that immediately inactivates exhaled pathogens. I estimate it takes 100 mW of far-UV about 5 minutes to inactivate 90% of the flu/covid in a 250 sqft ro
6.
by vbelenky 8mo ago
Shrug. Nothing is 'harmless', including far-uv. Going outside in the sunshine isn't harmless. The stove in your kitchen isn't harmless. Can you prove your stove isn't going to explode some day and kill you? No, but
7.
by vbelenky 8mo ago
I'm not sure what you mean by clinical unit--the ushio care222 is the longest lasting KrCl emitter I'm aware of, but as all bulbs age, they tend to degrade just by losing output, not by spectral shifting. Basically everyone in far
8.
by vbelenky 8mo ago
Nah--use 254nm for that. It's a standard thing, if it's contained in a duct it doesn't need to be fancypants human-safe 222nm. Ducting it kills most of the effectiveness though--now you have to move air through your ducts in
9.
by vbelenky 8mo ago
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 it
10.
by vbelenky 8mo ago
Two studies that I'm aware of, but yeah, data is thin on the ground: https://www.mdpi.com/2076-3417/13/7/4141 https://www.boeing.cn/cti/downloads/Boeing-Compatibility-of-... Su
11.
by vbelenky 8mo ago
The spectra are slightly different, but Nukit is also filtered, I would expect it to be just as safe--just lower output
12.
by vbelenky 8mo ago
Kinda like advertising "Asbestos-Free Cereal" isn't it? If someone was marketing a product to me and they were super insistent about how super duper safe it was I would probably start getting suspicious
13.
by vbelenky 8mo ago
Nichia is pretty top of mind for me as a solid supplier of 265-280 nm LEDs https://led-ld.nichia.co.jp/en/product/uv_top.html . Decently high output, decent lifetime (especially the longer wavelengths). There'
14.
by vbelenky 8mo ago
I don't really think 222nm UVC LEDs are going to be super relevant anytime soon https://www.convergentresearch.org/resources/convergent/soli... SHG chips might get there but they're very early days right
15.
by vbelenky 8mo ago
Pretty sure that's a UVB flashlight. There's absolutely no way that anyone is selling 255nm UVC that outputs much of anything for more than a few hours for $45. A good 280nm chip is ~$100 ( https://www.ledsupply.com&#x2F
16.
by vbelenky 8mo ago
The uviquity 220 nm SHG chips are super cool--they're perfectly monochromatic (though maybe with some blue light leakage) and I hear from their tech lead that they expect to get up to 10% WPE. I think that approach is definitely going
17.
by vbelenky 8mo ago
If it's mounted at the recommended 8.5 feet, it's ~impossible/extremely unlikely for the people in the room to get a dose that exceeds the 222nm threshold limit values set by ACGIH (see here https://uvmedico.com&#x
18.
by vbelenky 8mo ago
1. UVA/UVB is more efficient in terms of $/watt than 222nm KrCl*, but they're FAR less efficient in terms of germicidal dose than UVC (both 254nm and 222nm). You have to output a LOT of UVA/UVB to kill pathogens at anywh
19.
by vbelenky 8mo ago
The filter is a hafnium oxide interference filter! There are some absorption-based filters being studied in academic settings (as they'd be potentially cheaper to manufacture) but none are used commercially as far as I know Honestly th
20.
by vbelenky 8mo ago
>This lamp would kill those friendly microbes. Not really. Those microbes live deep in your pores where the UV wouldn't reach. Even if the UV totally scoured the surface of your skin, it would only be a temporary disruption, which w
21.
by vbelenky 8mo ago
You can filter viruses with mechanical air filters, but based on the available data, far-UVC can do this much faster than even a high-CADR air filter. The best filter I'm aware of can deliver 200 CFM of clean air quietly or 400 CFM lou