My very naive baseline for questions like this is "large effects are easily measured", and the contrapositive "if it's hard to measure, the effect is small". Can you explain why this isn't the case for far-UV? Also, what are the reasons there doesn't seem to be much ground-up interest? Why aren't companies and homeowners installing it in such numbers that it becomes standard?
Far-UVC probably would have a large effect if a particular city or country installed it.
But if only a few buildings install it, then it has no effect because people just catch the bugs elsewhere.
Imagine the effect of just treating sewage from one house, and leaving all the untreated sewage from a million houses untreated in the river. There would be essentially no effect.
If you installed it in a preschool and it successfully killed all the pathogens there wouldn't be essentially no effect.
Yes, certain places like preschools might benefit even from an isolated install.
But that is kind of exceptional.
The world isn't an efficient market, especially because people are kind of set in their ways and like to stick to the defaults unless there is strong social pressure to change.
Ah, OK. So the claim is that the isolated effect (one building, even an office or home with significant time-spent) is small, but the cumulative effect is nonlinear in some way (either threshold effect or higher-order-than-linear). That IS a lot harder to measure, because it's distributed long-term statistical impact, rather than individually measurable impact. I'd think that we have enough epidemiology knowledge to model the threshold or effect, but I've been disappointed on this front so many times that I'm certainly wrong.
It, unfortunately, shares this difficulty with other large-scale interventions. If it's very expensive, personally annoying (rationally or not), and impossible to show an overwhelming benefit, it's probably not going to happen. And IMO, it's probably overstated in feasibility of benefit.
Why there isn't more ground-up interest: it's expensive and people can't easily tell if it's worth the cost. Also anything where UV is touching you has to overcome people's safety concerns.
Good question on the large effects are easily measured thing--has to do with the distinction between: 1) in what environments you are cleaning the air, 2) how much you are cleaning the air there, 3) how much pathogen people inhale, and 4) how much pathogen is required to actually make people sick. It's not just a far-UV problem, it'd be a problem for any air cleaner, it's just that far-UV is especially expensive to install and especially faces negative "UV" associations.
Far-UV has a large effect on airborne pathogen concentration, and that large effect is in fact easy to measure in a chamber! But once you add it to a room where people are moving around and talking to each other, how much pathogen are they actually inhaling? Is the air in the room well-mixed? Is the far-UV reaching the infectious air before people inhale it? Even if they inhale air that has living pathogens, are they getting sick? If they get sick, did they get sick from that room or from a different environment that they were in previously? Study endpoints matter a lot.
Being able to understand intervention efficacy especially becomes a problem if a disease is largely spread via superspreaders/had high variance in infection sources. COVID, at least early in the pandemic, had very high variance, whereas eg seasonal flu doesn't usually. Therefore, if your study intervention is installed in public spaces, it's possible for it not to show much effect on seasonal flu but a large effect on a disease with early-COVID-like dynamics, which means you have to wait for that COVID-like disease to come along to see the effect--but that would be worth it; high-variance diseases are very concerning!
Another way of saying all this is that it's not the case that the effect will be super hard to measure given enough people and time, it's that the effect is hard to measure given that you need a lot of people in your study to account for the distinctions listed above, and/or you need a highly controlled environment, and that's just expensive.
I’m stunned that the word “duct” doesn’t appear in this article. UV in ductwork is cheap, very effective, and has no downsides. I’m flummoxed why it isn’t widely employed. Can you help? Thanks.
Had something of a similar reaction but the note about far-UV not having the same problems as other UV serilization (i.e., also harmful to humans) I gather the point is about locality. UV in ducks will kill viri in the air system. But the spread of an airborn illness goes host-to-target before it passed through the air system.
As such seems that while the in-duct UV solution would help limit spread, it's not going to do much to clean the air in the room while people are in it exhailing, coughing or sneezing, talking....
I suspect it does little to protect the people directly next/in front of a contagious person but probably good for those practicing that old 6 foot rule (or whatever the arbitray distancing rule was).
Just my guess though.
The word duct doesn't appear here because far-UV installation is most useful (compared with other wavebands) for whole-room application--agree that UV in ductwork has the potential to be very useful, but you'd use a longer wavelength if people weren't going to be directly exposed, because you can crank up the power on longer UVC wavelengths without producing tons of ozone. (Far-UV is specifically 200-230 nm, but UVC goes up to 280 nm.) I focus on far-UV because the excitement about far-UV specifically has to do with whether there's potential for it to be installed in such a way that it can stop in-room pathogen transmission before air entirely circulates or recirculates, which could be a big deal for pandemic prevention.
Why in-duct UVC isn't more widely employed: I don't know a ton about its current adoption level but retrofitting ductwork is a hassle, even just in the simple sense of needing to contract technicians to do it. Anyway, its efficacy isn't guaranteed; you need to know the power of the light you're getting, which many consumers are not equipped to assess. The efficacy is a combination of the light's power and the speed of airflow through the duct, UV lights are often sold at an insufficient power to effectively disinfect air, and consumers can't necessarily evaluate whether it was a good investment (common problem across air cleaners in general).
My guess is that we're still on the leading edge of ordinary consumers thinking of air quality as something that they can and would want to control for anything beyond comfort, particularly for pathogen (or allergen, or mold) removal. All air quality tech faces that problem (and my blog post was trying to address the problems far-UV faces beyond that). Anecdote I found interesting: Some colleagues attended a global indoor air quality conference earlier this year and reported that something like 80% of the sessions were about comfort in the indoor environment, while about 5% were about pathogen control.
I'd be interested to know what the numbers on UV in ductwork look like over the past 5 years. When I had to get a new A/C system installed in 2020, they asked whether I wanted a UVC light installed in the air handler. I had, before then, been using a 70w UVC corn light I bought on Amazon to sterilize the exterior of groceries (back when we thought fomites might be a major transmission vector), and in improvised ductwork with fans and cardboard boxes taped together.
Getting a proper bulb--an optimal wavelength source--seemed like a big upgrade. Hard to come up with quantitative efficacy numbers, but we did have a friend over for the day, who turned out to have been in the early stages of covid, without getting infected. Our first infection was years later, at a music event.
The US government is large. Just because one part of the US government is not willing to fund the work does not mean that you might not get another part to fund it.
NLP (as in Neuro-linguistic programming) has the problem of the academic research community in psychology being very prejudged towards NLP and thus it was hard to get any mainstream outlet to get research funding to research the effects of the Fast Phobia Cure in NLP.
The solution was to go to the military and present the Fast Phobia Cure as a solution to PTSD of war veterans. The military funded studies of it under the name RTM Protocol and it's now one of the interventions for PTSD in war veterans with the most support from academic studies.
I would expect that it's pretty bad when your soldiers are in a war zone and get incapacitated with the flu. Being able to have an effective military even during pandemic scenarios whether those are of natural origin or artificial induced for military purposes, is likely important to military planners.
The US military did publish some research into the effectiveness of masks in preventing COVID.
My description was a pretty quick gloss, but yep, the government is large and I know partners have been inquiring with various offices. Getting money is always going to be a problem. Honestly part of it is, let's say it takes three years to get funding for [something you care about], it's not actually that long in government timelines but it feels like forever when you work at a small organization or company and your work revolves around that particular thing.
Quick comment regarding research.
If far-UV is really so great, and not that simple, I would assume that any company that would be selling and installing might not be some small Mom and Pop type operation. If that holds, why are the companies that want to promote and sell the systems using them and then collecting the data?
Or is would that type of investment be seen as too costly even for those with a direct interest in producing the results to bolster sales and increase the size of the network/ecosystem?
(Let me know if I misunderstood; I'm reading your second sentence as "why aren't the companies...") On company size: The industry is split between emitter companies and consumer product companies; the emitter companies sell the far-UV emitter (basically the lightbulb) to a different company that builds the housing for consumers. The emitter companies are usually a branch of a larger electronics/lighting company; the consumer product companies are usually very small.
Some companies have run their own studies, but most of their installations are much too small to be studies in themselves. One problem I've heard about in the case of at least one larger installation is that the customer who sought the installation wanted the data to remain confidential. Otherwise, large studies are indeed mostly too costly for these companies to self-fund entirely, but they may offer partial funding or provide their lamps at-cost or as donations to studies.
Apart from potential harms of far-UVC, it's good to remove particulate pollution anyway. Is it possible that "quiet air filters" is an easier problem to solve?
Quiet air filters is an already solved problem technically. You just need enough filter area that the pressure drop is low, so that you can use quiet low-pressure PC fans to move the air. CleanAirKits is already good, but if the market were big enough cared enough, rather than CleanAirKits charging >$200 for a box with holes in it and fans, you would get a purifier from IKEA for $120 which is sturdy and 3db quieter due to better sound design.
IKEA already sells air purifiers; their models just have a very low flow rate. There are several companies selling various kinds of air purifiers, including multiples ones with proprietary filters.
What all this says to me is, the problem isn't just the overall market size.
Yeah that's right, I should have said market for good air filters. My understanding of the problem is that most customers don't know to insist on high CADR at low noise levels, and therefore filter area is low. A secondary problem is that HEPA filters are optimized for single-pass efficiency rather than airflow, but they sell better than 70-90% efficient MERV filters.
The physics does work though. At a given airflow level, pressure and noise go as roughly the -1.5 power of filter area. What IKEA should be producing instead of the FÖRNUFTIG and STARKVIND is one of three good designs for high CADR:
I made a shortform and google slides presentation about this and might make it a longform if there is enough interest or I get more information.
If this is so promising, why isn’t it everywhere?
Excellent post, answers that very well for this specific problem. Nowadays my general answer to this question (if I can get away with using it) is to point the asker towards Inadequate Equilibria and/or Moral Mazes.
(Austin is very kind--I am not close to being the world expert in far UV deployment; there are people who run/used to run companies trying to do that, and researchers who work with them very closely, who know more about far-UV deployment, and I'm largely consolidating information from them.)
Crossposting this essay by my friend Gavriel Kleinwaks, who is approximately the world expert in Far UV deployment.
[Edit: Austin is very kind--I am not close to being the world expert in far UV deployment; there are people who run/used to run companies trying to do that, and researchers who work with them very closely, who know more about far-UV deployment, and I'm largely consolidating information from them. -Gavriel]
Disclaimer: In the interest of avoiding the problem where a post languishes in drafts forever, I am not attempting to be particularly rigorous, but I’m happy to answer questions to fill in details about how I’ve come to the conclusions I’m writing about. This post is informed by my work experience at 1Day Sooner, but only reflects my personal takes, not the official stance of my organization.
I work on indoor air quality to reduce disease burden and pandemic risk, and far-UV is an extremely promising intervention. One of the questions I get most often is, “If this is so promising, why isn’t it everywhere?” The answer requires a lot of breakdown and I get a lot of follow-up questions as soon as I start to answer, so this post is an attempt to run through the entire conversation at once. I’d never actually get around to posting this if I also included a deep dive on far-UV or tried to prove its value, so if you don’t know yet why it’s promising, you can check out this report.
Top line takeaway: Far-UV isn’t widely used because no individual organization has the incentive or bandwidth to install it, and the industry is stuck in a vicious cycle, making companies unreliable. Filtration is already widely used, but more user-friendly filters would greatly improve implementation.
Q: What are the major roadblocks to widespread use of high-quality filters?
A: The market is hard for consumers to navigate; it’s difficult for consumers to be well-informed enough to assess which filters are high-quality. For example, ionizers (ozone producing and, according to some researchers, basically ineffective1) and portable HEPA filters (no harmful byproducts, universally agreed to be useful) are both sold as “air purifiers.”
Q: What are the major roadblocks to widespread use of far-UV?
A:
Q: Okay, sounds like more real-world research is needed on far-UV. What are the major roadblocks to that research?
A:
Q: So far-UV is facing a vicious cycle. What differences in the state of the world would break the cycle—i.e. What’s your wish list?
A:
Q: If you need big research funders or a high-profile installation, why not try to start a government research program? This seems like exactly the sort of thing they do.
A: The American government is institutionally conservative/risk-averse and we have heard from government offices that they want to see more excitement from the private market before initiating their own investments9 in research. However, we really hope that governments get excited about far-UV eventually. One very reasonable outcome would be for us to find, through careful research and statistical analysis, that far-UV is almost never worth it for individual private-sector actors to use in peacetime, but that far-UV is invaluable during a pandemic. If that is the case, it would be important for the government to stockpile far-UV lamps and pay for their widespread installation, to only be turned on in the event of a pandemic.
Q: Are there any good standard-setters outside of the government?
A: America’s authoritative voice on indoor air quality is the American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE). They have no regulatory authority, but their standards are used and referenced by many other organizations, and some building codes require compliance with ASHRAE standards. As a professional association of HVAC engineers, the general body of ASHRAE doesn’t have much epidemiological expertise and isn’t traditionally focused on disease reduction. The COVID pandemic brought indoor air quality to the forefront of epidemiology, so ASHRAE has had more interest in disease reduction, but their standards still focus on HVAC interventions and do not provide guidance on the use of germicidal UV.
Q: If ionizers produce ozone and have mixed evidence for their efficacy, why aren’t they facing the same market issues as far-UV?
A: This question keep me up. Far-UV manufacturers will say that it’s because ionizer companies are better at sales, have bigger backers, and are more willing to use dishonest sales tactics, but that only kicks the question back to why far-UV companies are worse at sales and lack these same large backers as ionizer companies. I have no direct experience of ionizer companies’ sales tactics, but my experience with far-UV sales is that, in general, salespeople communicate very differently from researchers in ways that can read as dishonest, and that the field of far-UV is not uniquely virtuous about communication style when business is on the line. I believe that the success of ionizers has more to do with their purported use for eliminating other pollutants (not just pathogens) from the air, so consumers view them as an all-purpose air cleaner. Ionizers also started being marketed for home use in the mid-1900s, before the health concerns of ozone inhalation became widely known, so it’s possible that ionizers were just a well-timed product, and that now their use might slowly die off.
Q: Do you have a wish list for filtration?
A: Filtration doesn’t face the same hurdles as far-UV in terms of the vicious cycle relationship between research, market adoption, and government investment, and because it has benefits aside from pathogen reduction. We only spend so much time talking about far-UV because it takes longer to explain as a technology and because the adoption problem is so complicated. The problems with filtration are already being addressed by other parties, who have much greater comparative advantage in this area, so filtration doesn’t “need” 1Day Sooner. My wish list for filtration, which is already well underway, is:
I may add to/edit this list as more questions occur to me or as I learn more about the far-UV market. Thumbnail image from this biodefense meeting because I thought it was funny.
Personal communication with multiple researchers. I have not personally reviewed the literature—a quick glance shows research that seems to both prove and disprove the usefulness of ionizers, but generally I trust the researchers who I spoke with. As a history note, a coalition from the ionizer industry once sued a large group of air quality researchers over publishing research with negative outcomes.
Chamber studies can help address this type of uncertainty, but imperfectly—it’s hard to set up a chamber that imitates all the factors you’d want to consider, such as molecules’ diffusion or deposition. These factors might make far-UV look riskier than it really is, or they might mean that important considerations are missed.
Personal communication with a researcher who tried this avenue.
A study in nursing homes in Nova Scotia has been approved and is currently underway; the entire field is breathlessly awaiting results.
Yeah, this feels a bit like a distinction without a difference to me.
Corollary question that I get because of living in San Francisco amid the starry-eyed tech adventurers and entrepreneurs-by-temperament: If I think that having a reliable far-UV lamp is necessary, why don’t I go found a startup about it?
On the personal fit side, I’m just not that driven to found a startup. It’s not my comparative advantage and I don’t think I’d enjoy it that much—but who knows. As for the field itself, far-UV hasn’t made anyone any money yet; hence the existing companies being constantly on the brink of going out of business. Anyone getting into this field would have to just commit to eating a very large loss that I am not willing to contend with. This type of coordination problem definitionally can’t be solved by the market. (I definitely hope that this line of business becomes profitable; just describing the current state of affairs.) Plus, engineering in the physical world has very high overhead—if I wanted to work on the mechanics of far-UV, I’d just go work for the nonprofit working on that and increase their bandwidth and help them work faster, rather than start from scratch to figure out manufacturing best practices and whatnot. (Of course, this very much relies on my belief that the nonprofit in question is good at what they do—people in other industries may very well see many more opportunities to fix things that other people in the field are doing wrong.)
That all being said, I very much believe that the entire far-UV field shouldn’t rest on the shoulders of one or two manufacturers, so if you are a mechanical engineer digging around for new challenges and you’re not put off by everyone else’s failure to turn a profit, I’d be enthusiastic about your building a lamp and would do my best to help you get in touch with people you could learn from.
Personal communication with the group.
Personal communication with an industry sales rep. We were discussing a large but low-control study that some researchers were preparing, and he was pretty scared that it would show no effect. I was surprised to hear that he considered scientific literature so paramount to his business, because I figured that potential buyers never read the scientific literature anyway, but he told me that the decision-makers, like facilities managers, work with engineers who do read the literature, and that investors and research grantors do too, and null results make them disinclined to invest or fund higher-control research.
Why run low-control studies anyway? They can be much less expensive (depends on the setting) and they’re more reflective of real use!
Ironically, government research and a government standard would probably make everyone else in the private sector feel a lot better about far-UV! While navigating this field, it has felt like each group is waiting for the other to move first.
Corollary: it might be that one good use of philanthropic money would be to heavily subsidize and distribute ClearAirKits filters, or take out a massive ad campaign for them. My guess is that such a project wouldn’t meet an EA funder bar, but would be good for some major public health funder that likes local/immediate community work, like Chan Zuckerberg. I have not researched this carefully.