A paradigm shift to combat indoor respiratory infection
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I think this is the key question. Surely better ventilation would have prevented some infections in the covid pandemic. But how many? And to decide that we need not just manifestos by civil engineers (like this article) but convincing research results, probably in collaboration with people who actually know some things about viruses as well. And without it, could organizations like the WHO or CDC have plausibly recommended building upgrades?
It’s really hard for me to read a WIRED article for information.
I mean I realize that’s not what it’s there for but it takes forever to get into the content of the article.
Now, to take the ferry cost a nickel, and in those days, nickels had pictures of bumblebees on 'em. Give me five bees for a quarter, you'd say.
I've found this is the style of American long-format journalism in general. Just look at something like The New Yorker: not to dispute the quality of their writing, but the word counts certainly skew high. Articles in comparable British publications tend to be a lot more succinct.
When I lose track while reading an article, or find difficult to understand it, I stop and reading it bottom up, one paragraph at a time. First the last paragraph, then the one before that, etc...
This cuts through directly to the conclusion, then the detailed explanations form particular to general (which works better for me) and I can skip the "excitement build up" at the top of the article.
I applied it to this[1] super long winded article in New Yorker to get the gist of the article. This article is littered with these passages and it's super frustrating. In the end from my view point it's a shallow piece with very little new insights. FWIW the article didn't age well as India is being ravaged by the 2nd wave.
[1] https://www.newyorker.com/magazine/2021/03/01/why-does-the-p...
Good news articles should tell you everything in the headline. Then tell you everything again in the first body sentence. Then tell you everything again in the first paragraph. and the first page. And so on.
It's supposed to be a fractal that unfolds additional detail as you press forward, while ensuring that even a casual reader comes away with a mostly complete and accurate understanding of the issue.
More of THAT please.
And yet, news media are the last place you're likely to find articles written in this style. Somehow, they manage to deliver the exact opposite of what they should be. A fractal of confusion, recursively unfolding noise.
(It's as if they were making a lot of money on maximizing the time a reader is engaged with any given article. It's as if - and I know this sounds crazy - the articles were there just to hold the user down, while they're being exposed to something else...)
Narrow (succinct) at the top and broad (detailed) at the bottom seems like a normal pyramid to me.
An "inverted pyramid" would be like one of those poems that describes fine details first and only in the last sentence reveals what it's been describing.
I don't doubt that it's actually called that, but it seems backwards to me.
It is ordered most relevant to least.
Practices which show contempt for the reader's time and interest are ultimately counterproductive.
The first is because, yes it allows busy readers to access the most salient facts first. But secondly, and perhaps more importantly from the point of print newspaper production, it allowed subs to always cut from the bottom, without having to read the whole piece carefully...
Newspapers would go through several editions throughout the night as new stories came in or existing stories were expanded. What started life as a front page lead might find itself moved to page three and progressively shortened, possibly down to a 1 sentence news-in-brief NIB.
The pyramid style let subs always fit a story into the available space, simply by cutting everything progressively from the bottom.
This story in Wired is not a news story and is not written as a news story. It is a feature story and its construction follows different rules.
It's a very good feature story, in my opinion.
I'm not accusing you of doing this on purpose, but there's a certain amount of equivocation in the phrase "news article" there. Yes, that's a style that is recommended for factual news articles in a newspaper context, but that's not the only form of "news article".
Call this a "news essay" instead and give it its own style and it might make more sense. It's been around for a long time. Could call it the 20th-century equivalent of clickbait and probably not be far off.
"There's an exciting revolutionary change to physics coming... but first, the full life story of the thesis advisor's influential father... keep reading...."
Arguably it's more a form of entertainment than information.
No novel is allowed to lollygag around the point its trying to achieve in the way these articles flagrantly waste your time.
It's like someone misunderstood that the act of moving your eyes along the page is not interesting in and of itself.
With barely less than a second's though: Watership Down, a hugely popular novel in the 1970s, spends untold amounts of text/paper immersed in detailed descriptions of the flora that the characters are moving through or eating.
Why not just say "I don't enjoy this style of writing", rather than trying to come up with some supposedly objective metrics for how other people should write?
The distinction can be quite arbitrary, but it usually does stand out.
Herman Melville and Neal Stephenson also come to mind. In nonfiction, John McFee.
I'll also frequently apply this to HN comment streams.
1. Collapse the top comment. It's frequently good, but also frequently is an avalanche of compounded hot takes.
2. Scroll to the bottom of the discussion. Odds are that comments are lower-quality, but not always. I collapse these as I go up, upvoting the underrated ones. Occasionally comment.
3. If there's a long stream of lower-quality / redundant comments, I'll collapse those as well.
I really wish there were some way to surface more deeply-nested, high-quality comments. There isn't. (Though occasionally an email to mods will elevate one to a top-level comment.) There used to be a periodic HN curation. That no longer occurs AFAIU.
However, almost every article follows such a predictable format: Introductory section, full of all the interesting and tantalizing details, and stuff you actually want to find out about. Then section two: we jump back to the main subject's childhood, what clothes they were wearing when the journalist met up with them, how softly they speak. About two pages of biographical content. Section 3: we jump to the background of the story we're actually going to tell. Explain how it fits into the history of some movement or scientific question or whatever. The "point" of the article gets buried somewhere in sections 4 or 5, in between riffing on other people's dead ends and more biographical content.
Here's a counterexample literary trainwreck from the BBC. Have a go at wading through this horror show. It appears to have been written deliberately to withhold the topic of the article from the reader, for as long as possible. The wholly uninformative title is just the beginning. Those with the necessary patience will eventually realise that the title is also plainly untrue.
You’ll see a pretty high correlation between fans of “long form”, readers of The Atlantic and The New Yorker, and political inclination around being perceived as erudite.
It’s one of those cargo cult mixed with a measure becoming a target.
https://twitter.com/jljcolorado/status/1391111720526024708
Credentials: https://www.colorado.edu/chemistry/jose-luis-jimenez
The physics of small particles moving in the air ("Brownian motion") was completely figured out by Einstein back in 1905.
Given a virus' size and weight, it should be trivial for a physics graduate student to simulate how long it will be airborne.
And so medicine is understandably a slow moving science, and the practice of medicine moves even slower as it represents the slow filtration of the cutting edge of medicine the science, through a complex web of human interaction. Which with a dash of “social capital” theory, makes it easy to see why we have unfortunately often ignored sound advice like this. The mistaken assumptions of people viewing a person who’s expertise bridges two disparate fields, as being unable to understand things as deeply, clearly or fully, as the people dedicated to just one of those fields.
FACT: #COVID19 is NOT airborne.
The #coronavirus is mainly transmitted through droplets
generated when an infected person coughs, sneezes or
speaks.
To protect yourself:
-keep 1m distance from others
-disinfect surfaces frequently
-wash/rub your hands
-avoid touching your Eyes Nose Mouth
The WHO gave a lot of bad advice. Some say that it was intentionally misleading. Promoting ventilation as a reasonable treatment for the initial stages of covid-19 was the worst possible advice to give front-line medical practitioners who didn't know what they were dealing with.
We now know that the fecal-aerosol route of transmission is very important. Forbes has a recent piece about the fecal-oral/aerosol route: https://www.forbes.com/sites/williamhaseltine/2021/03/22/pre... Another tweet by ... someone was about how the masks effectively aerosolize droplets.
Keeping bathrooms open but requiring face coverings was an exercise in futility.
In the case of COVID-19, the WHO seems to have implemented #PrasadsLaw [0]. "Prasad’s Law: Medical goods and services that concentrate wealth can be paid for; medical goods and services that disperse wealth are “unaffordable.”"
How long it remains airborne is beside the point. Does that physics grad know how long/if the virus can survive once it dries up? Do they know how long it will survive exposure to light? Do then know whether the virus can cling to dust particles?
Even brownian motion is only half the story. Does the physics grad understand airflow in office spaces? Do they understand how fast air moves when a person coughs? How much turbulence is caused by opening an office door? Plenty of things can stay airborne for extended periods because of aerodynamics without regard to brownian motion (snow/rain/dust/salt etc). That physics grad better come with minors in aerodynamics, kinesiology, microbiology ... even some basic meteorology would be helpful.
You can make the same arguments for drinking water, and yet, as long as you follow the rules, it is unbelievably safe, despite the fact that no one gave a shit about turbulence along the baffles in the treatment tank.
> Given a virus' size and weight, it should be trivial for a physics graduate student to simulate how long it will be airborne.
This is also in the article, known research from decades ago. Social distancing is in fact based on a misunderstanding and conflation of a few things in that early research.
Wired: EARLY ONE MORNING, Linsey Marr...
OP article: A paradigm shift to combat indoor respiratory infection ... Linsey C. Marr (in the author list)
Wired: . At one point, Lidia Morawska,
OP Article: Lidia Morawska (first listed author)
https://twitter.com/jljcolorado/status/1391111720526024708?s...
It's 100 tweets long, may be more readable here : https://threadreaderapp.com/thread/1391111720526024708.html
I would guess an analysis of workplace COVID rates would see a strong correlation between workplaces with and without filtration in their AC systems.
With say 10 air changes per hour (injecting at the ceiling and extraction at the floor), and a 3m high building, you can expect airflow downwards at about 1 cm per second. That means there is perhaps only a 30 second window for a particular pathogen to hit someone else's nose before being pulled to below face level.
It's not nil, but I think that would lower transmission rates by a sufficient factor for COVID (and many other diseases) to become extinct.
In the open air on a grassland, covid won’t kill a population. The design of our hermetically sealed buildings is what’s killing us.
Back in the 1970s the air outside was full of lead and smog, so the safest thing too was completely seal all office buildings.
Today the air inside probably contains more hydrocarbons (from volatile organic compounds offgassing from carpets and furniture) so the best thing to do is vent air to the outside and keep the windows open (assuming you live in a mild climate)
Of course, that flies in the face of all efforts to make things green…which involve better insulation, sealing windows against leaks, more air filtration systems and etc.
Here in Canada the temperature drops like 5 or 10 degrees when you walk into a forest. I’ve stepped into a traditional mud hut and experienced a similar cooling effect. The common denominator is that both environments have a high surface area compared to say concrete. This acts as an efficient radiator so that when water to evaporates it removes heat. In low humidity climates this is one way to reduce cooling demands. Beyond that if we cool micro zones or interstate cooling into clothing itself through hoses or something that might be the next step in efficiency…until it gives birth to the next problem.
If anyone has a half-hour of time to waste, you can look into the science of "countercurrent heat exchangers".
It's fascinating to see how 2 pipes of air current switch temperatures when they're in contact and moving in opposite directions.
So if you want to be green AND have fresh air constantly circulating through a building, then forcing the warm inside air to pass by the cold outside air as they leave/enter the building can lead to somewhere around 95% energy recovery.
Add in a humidifier to the incoming air, and you'll have a comfortable room with humidity that will attach to airborne droplets, prevent evaporative release of a raw airborne virus, and help pull the droplet down to the ground via gravity.
Shouldn't the air ideally move in the same direction?
In a countercurrent heat exchanger, the hot air will get colder and colder until it is at the same temperature as the cold air, and the cold air will get hotter and hotter until it is the same temperature as the hot air.
This is because the hot air is not warming up the same air molecules that it relies on to cool down, and the cold air is not cooling down the same air molecules that it relies on to warm up. Each current of air gives up a part of their heat/coldness, becomes colder/hotter, and then moves towards a section of pipe that's even colder/hotter than the previous section of pipe.
A picture is worth a thousand words, although it takes some staring and studying before the concept finally clicks: https://en.wikipedia.org/wiki/Countercurrent_exchange#/media...
But even recovering 95% of heat isn't exactly great. If you live in Canada and have a 2600 sq ft house with 8 ft ceilings and 10 changes of air per hour, and the indoors is 70F and outdoors is 0F, thats 2600810 cubic feet of air/ per hour, or 12000 BTU/hr. That means you are more than doubling your heating costs compared to sealing the building and just having conductive losses through the walls.
This is true for most climates - even the best energy recovery systems still double heating/cooling costs compared to having barely any fresh air.
And we're looking at the margins; 1 air change per hour can do wonders for preventing the spread of disease and improving air quality, compared to 0 air changes per hour.
Nevertheless, I redid your math, and found that your hypothetical home has 26,728 more BTUs of energy in its air, compared to the outside air[-1][0][1], and that the recommended furnace for such a climate should be 160,000 BTU/hr [2].
Using those numbers as a base, I find that, with an efficiency of 95%, it would require 120 (that's one hundred and twenty) air changes per hour to double heating costs.
With 60% efficiency, it would require 15 air changes per hour to double heating costs.
And it only takes a few air changes per hour to increase comfort and prevent illness.
[-1] I suddenly realized that the google search links that I used for these calculations are messy and unwieldy, so I'll summarize my calculations: (2600 ft^2) * (8 ft) represent the volume of the house; (1.225 kg / m^3) represents the density of air, (1.005 kJ/(kg * Kelvin)) represents the specific heat of air, (70 * (5/9)) represents the temperature difference you gave me, in Kelvin. Multiplying everything together, and letting Google automatically take care of unit conversions, gives me 28.2 MegaJoules of energy in the house.
[0] https://www.google.com/search?q=%282600+ft%5E2%29*%288+ft%29...
[1] https://www.google.com/search?q=convert+28199142.9+joules+to...
Or maybe I had less than ten air changes?
Very interesting! The concept makes a lot of sense, and I was able to find some companies online that produce such a thing, often under the phrase "counterflow heat exchanger".
Frustratingly there's little details online for actual pricing, but you can find the bare exchange units on ebay for $200-300.
From what we know it started in Kansas. It should be called 1918 Flu Pandemic.
Also: heat recovery percentages don't always include the energy required for forced air movement through the exchanger.
There's a sizeable chance it would be extremely weak and that'd we'd be incapable of resisting many disease on our own and therefore would become completely dependent on the air cleaning infrastructure.
You’re right that our immune system didn’t evolve to be in a sterile environment. But we also weren’t meant to be that close to that many humans.
Can you catch airborne respiratory diseases from eating fruit?
What I'm saying is: we run the risk of never being able to go outside again if we eliminate all airborne pathogens.
I'm willing to speculate that exposing our immune system to surface pathogens helps deal with airborne pathogens.
“When Adams explained that he didn’t want to catch an illness from the cold night air, Franklin countered that the air in their room was even worse.”
https://www.mentalfloss.com/article/54169/time-ben-franklin-...
The night air is dangerous, close those windows before you go to sleep!
Neither cholera, malaria, typhoid nor plague are airborne, and yet their causes were ascribed to miasmata.
> VOCs are produced by animals and microbes
Try to have substantiative things to say instead of spouting off false declarations and inflammatory insults.
Hopefully we'll make those changes if and only if doing so brings significant health benefits.
while most mask usage in practice has been completely useless (like double-masking or wearing them outside), the one place where masks make real sense is between two faces close to each other emitting exhaust indoors. if we had just relentlessly kept to this one crucial scenario in our mask messaging (and simply distancing everywhere else inside), we'd have had much better and more targeted mitigation, with dramatically fewer downsides to our social and economic lives. and to boot, that avoids trying to make extraordinarily costly upgrades to every hvac system in the world for marginal benefit.
My personal completely unscientific musings on the topic ended with buying and cutting up a couple of vacuum cleaner hepa filters, thus obtaining a shocking quantity of filter cloth, which then can simply be taped over the standard AC mesh filter. AFAIK, "hepa" ACs don't even cover the full surface - they just have a patch of hepa, which just ensures the air inside gets circulated through it eventually - being recirculated, there's not that much of a hurry. I'd recommend low-end filters, you don't want to remove virus particles but much larger clusters of virus+saliva.
So personally I'm guessing a rather high impact for very low cost / low effort changes.
Just raise the air exchange per person and or per volume by a significant factor and mandate a very fine particulate filter. You could do many measurements and lots of theory but nobody is going to engineer their buildings like cleanrooms anyway so the results of a lot of science wouldn’t be so good regardless.
Just have the inspector crack out a CO2 and PM2.5 meter during the inspection. Set legal limits and have a fee for exceeding them. Make it apply to existing buildings too, so building owners can choose to trade off increased HVAC costs Vs reducing the fee Vs costs of retrofitting better ventilation.
Obviously the measured numbers vary a lot day to day, so if a building owner isn't happy with values measured on the day, let them take an average over a week or something.
I had the experience a couple of years ago of working in an office with visible smoke from a meat smoker working downstairs. The owner and employer had 'independent' tests done with no issue found. Fuckers.
I do reckon there is a rather disgustingly unequal relationship between people that own or build a building and people that have to deal with sickness from working in a building.
Overwhelmingly, upfront costs for systems which prioritise airchange, occupant health, and energy savings are more expensive to install but cheaper in the long run.
Not saying it shouldn't be done but it should be done in a smart way that balances between tradeoffs.
I do think the initial cost to install/upgrade to such system would be substantial, though (as in, existing systems may not have the capacity to ventilate that much.)
An alternative in the meantime is to use a PAPR (powered air purifying respirator), which are more efficient, last much longer (device and filter), and are much more comfortable than N95 masks. I use an Optrel Swiss Air and cover the valves of the mask with a hoodie style balaclava.
It would be a good time to get one, as it is believed that it is only a matter of time before SARS-CoV-2 mutates into a variant that is capable of evading the vaccines.
Also, the US CDC advice may not have been such a good idea. Look at these calculations:
https://twitter.com/DrEricDing/status/1393090966928637952?s=...
Singapore has a comparable vaccination rate to the US and is going into lockdown to prevent further spread. They used Pfizer and Moderna vaccines. Just some food for thought:
https://twitter.com/andrewkimmel/status/1393086704349630464?...
The mRNA vaccines are stupendously effective at stopping all variants thus far. Not sure what evidence aside from fear point to covid being able to mutate past them.
We good, and it’s ok to accept that and have hope, not everything has to be fear-for-the-worst
Without the groundwork theory to rely on, you'd be hard pressed to convince new buildings to do something like that on a whim.
> You could do many measurements and lots of theory but nobody is going to engineer their buildings like cleanrooms anyway so the results of a lot of science wouldn’t be so good regardless.
This is a very strange and confused sentiment.
Haven't all of these steps been taken on airplanes already, to some extent? From what I see, the "personalized ventilation" idea is substantially similar to what aircraft ventilation does, just adapted for a workspace/building setting.
I would personally love a well designed slightly positive pressure dwelling with particle scrubbed inflow and egress (some kind of circulated water system like industrial sites have). Get rid of that pollen and everything else please.
Interesting article re: use in meat packing plants [1].
[0]: https://www.sciencedirect.com/science/article/abs/pii/S03088...
https://twitter.com/jljcolorado/status/1391111720526024708?s... (It's 100 tweets long, here's a more readable version : https://threadreaderapp.com/thread/1391111720526024708.html)
The tl;dr is that 20th century health authorities went too far in their rejection of the 19th century "miasma" theory of disease transmission, and now the pendulum is swinging back again.
It came again into my mind when I heard about tesla's biohazard filter system.
It's just ridiculous how we accept the status quo.
It can't be okay to be sick every year for 5-12 days and covid showed me no I don't have to be sick every year and don't get me wrong, clearly I'm not getting better in fighting this shit of if I have it every fucki g year.
What are long-term effects of being sick every year?
#AbolishCopyrights #AbolishPatents #EndIntellectualStupidity