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Austin Chen60

Hm, I expect the advantage of far UV is that many places where people want to spend time indoors are not already well-ventilated, or that it'd be much more expensive to modify existing hvac setups vs just sticking a lamp on a wall.

I'm not at all familiar with the literature on safety; my understanding (based on this) is that no, we're not sure and more studies would be great, but there's a vicious cycle/chicken-and-egg problem where the lamps are expensive, so studies are expensive, so there aren't enough studies, so nobody buys lamps, so lamp companies don't stay in business, so lamps are expensive.

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by jefftk
jefftk
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While this post touches on biosecurity it's a personal post and I'm not speaking for my employer

If you want to prevent airborne spread of diseases you have a few options:

  • Filter breath (masks, PAPRs)
  • Replace the air (ventilation)
  • Clean the air (filters, UV light)

Masks, fans, and air filters are widely available, but what about UV? The CDC recommends upper-room UV, it has a long history of successful use in with TB, and in many cases it's great fit for the space. Look on Yelp, though, and no installers come up:

Maybe people are missing a good business opportunity, or maybe it's the kind of opportunity that's only ok but is worth it for the altruistic impacts of directly reducing spread and normalizing UV? Seems worth finding out!

If you want to read more about how to set up upper-room UV systems, NIOSH has a serious document. At a high level, though, you want rooms that have a high density of people but also a reasonably high ceiling. Then you set up UV fixtures to shine so they clean the air above the people.

(Prompted in part by thinking that the Cambridge Masonic Hall would be a great place for an installation like this: crowded, tall ceilings, ceiling fans for circulation.)

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Start an Upper-Room UV Installation Company?
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[-]Austin Chen60

Another similar company I want someone to start is one that produces inexpensive, self-installable far UV lamps. My understanding is that far UV is safe to shine directly on humans (as opposed to standard UV), meaning that you don't need high ceilings or special technicians to install the lamp. However, it's a much newer technology with not very much adoption or testing, I think because of a combination of principal/agent problems and price; see this post on blockers to Far UV adoption.

Beacon does produce these $800 lamps, which are consumer friendly-ish. I bought one for the Manifold office, but due to a variety of trivial inconveniences (figuring out where to mount it; the mobile app not syncing with my phone) it's still not active. I think a competent operator in this space could make a device that's somewhat cheaper & easier to use, and hit a tipping point for widespread/viral adoption.

(If you or someone you know is interested in doing this and is looking for funding, reach out to me at austin@manifund.org!)

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[-]bhauth102

I'm not convinced that far-UVC is safe enough around humans to be a good idea. It's strongly absorbed by proteins so it doesn't penetrate much, but:

  • It can make reactive compounds from organic compounds in air.
  • It can produce ozone, depending on the light. (That's why mercury vapor lamps block the 185nm emission.)
  • It could potentially make toxic compounds when it's absorbed by proteins in skin or eyes.
  • It definitely causes degradation of plastics.

And really, what's the point? Why not just have fans sending air to (cheap) mercury vapor lamps in a contained area where they won't hit people or plastics?

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[-]Austin Chen60

Hm, I expect the advantage of far UV is that many places where people want to spend time indoors are not already well-ventilated, or that it'd be much more expensive to modify existing hvac setups vs just sticking a lamp on a wall.

I'm not at all familiar with the literature on safety; my understanding (based on this) is that no, we're not sure and more studies would be great, but there's a vicious cycle/chicken-and-egg problem where the lamps are expensive, so studies are expensive, so there aren't enough studies, so nobody buys lamps, so lamp companies don't stay in business, so lamps are expensive.

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[-]ChristianKl5-2

Quick Googling gives me https://northshorefuel.com/products-services/indoor-air-quality/uv-germicidal-lights.php . They seem near enough to install in Boston. 

Using Yelp to find a company that likely does B2B sales when you don't know the exact keywords they use, is not an effective strategy to find installers.

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[-]jefftk*102

That's a very different product, using UV inside HVAC systems as an alternative or supplement to traditional filtration. Because the delivery rate of HVAC as a fraction of all air in the room is so much lower than the fraction air above people in a high ceiling room, this is much less valuable.

Very roughly, the main ways people use UV to clean air to reduce spread of diseases are HVAC / in duct, far UV, and upper room. I'm only trying to talk about the last of these here.

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[-]Charlie Steiner5-2

Pointing UVC LEDs at your ceiling seems sketchy. White paint will likely scatter ~5% of UVC, and shiny metal surfaces will scatter more. Try to go below 250nm for reduced reflection (and reduced penetration into human skin) and (more) unwanted chemistry will start happening to the air.

I guess an important question is whether UVC is more harmful than UVB. If it's not any more harmful, then as long as nobody's getting sunburned from being in that room all day, it's probably fine - that 5% scattering is just another name for SPF 20. But if it is more harmful, then sunburn might not be an adequate signal for when it's bad for you.

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[-]jefftk62

You do need to pay attention to what paint is on the ceiling and measure to verify that levels are low in the places people are, but pointing UVC up is something we've done safely for a long time in many places.

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[-]ChristianKl30

If you want to do this as a successful company, you essentially have to get your customers to trust you that you are installing it in a way where UVC up does not produce any negative effects. 

People have been doing it for decades is not something that would convince me that there are not long-term side-effects. 

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[-]jefftk*94

The way you demonstrate that there are not long-term side effects is that we have very accurate ability to measure UV, and so you can show that the system being on vs off has a negligible impact on the amount of UV where people are. Long-term impacts would be downstream from this kind of easily detectable effect.

(I think this is very different for far UV, where you intentionally shine it in a way that does include the people. That is potentially a much better approach, because you can clean the air between people instead of only above them, but while the research on far UVC safety looks pretty good to me, it's a much harder system to gather safety evidence on.)

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