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Re:Pfizer is testing a pill that, if successful, could cure ... by Syzygies on Monday April 26, 2021 @08:15PM (#26950047)
CO2 is a good proxy for airborne infectious disease risk. Outdoor air is 400 ppm or so, best practice in modern building going into the pandemic was 600 ppm. Get CO2 down to 450 ppm and airborne infectious disease transmission plummets.

We have varied reactions to parts of the world that still suffer the consequences of human waste in irrigation water. In the far future people will view our current indoor spaces with similar varied reactions.

Re:Pfizer is testing a pill that, if successful, could cure ... by quercusa on Monday April 26, 2021 @09:15PM (#26950572)
> Get CO2 down to 450 ppm

And buildings will be much more pleasant. It's possible that people would be smarter, too (as opposed to being shut up in a badly ventilated conference room for an hour or two).

There are costs, as heat or/AC will have to run more to keep the temperature in the right range.

Re:Pfizer is testing a pill that, if successful, could cure ... by harry8 on Tuesday April 27, 2021 @12:35AM (#26952051)
Also widening the range would be a reasonable thing. Wear a jumper in winter. Don't be forced to go from 40C to 20C in summer. We don't need precisely the same temperature 24/7, 365.
Re:Pfizer is testing a pill that, if successful, could cure ... by marttt on Tuesday April 27, 2021 @01:17AM (#26952299)
Re:Pfizer is testing a pill that, if successful, could cure ... by derefr on Tuesday April 27, 2021 @02:03AM (#26952551)
That's nice for heat, but thermal mass means that air conditioning is most efficient when it can get the whole room to equilibrium and then shut off. Like a car coasting going down a hill.
Re:Pfizer is testing a pill that, if successful, could cure ... by sepin4 on Tuesday April 27, 2021 @03:51AM (#26953212)
I just bought my apartment last year and I made the decision to use infrared panels for heating. Best decision ever. No moving parts(no noise and no constant breeze), no dry air indoors, the heat is actually stored in the walls and furniture(denser objects), so I can vent the air regularly without loosing much energy. And it's supposed to help generate vitamin D which during the winter is usually a problem. The downside is that it takes longer than air conditioning to warm up the same room and it requires great wall and floor insulation(which I have). There is also the problem of overshooting the temperature(because the panels don't cool immediately, it takes about 15-20 min), which is solved in some thermostats using hysteresis algorithms for the temperature delta(it uses shorter cycles between on and off and more precise measurements, however this could wear the electrical panels quicker). I'm not that sensitive to the temperature so I don't use those and I have my temperature sensitivity up to 0.5C.
Re:Pfizer is testing a pill that, if successful, could cure ... by 05 on Tuesday April 27, 2021 @07:13AM (#26954412)
Sorry to disappoint you, but vitamin D3 synthesis is triggered by UVB, not IR

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3897598/

Re:Pfizer is testing a pill that, if successful, could cure ... by sepin4 on Tuesday April 27, 2021 @08:21AM (#26954912)
Yes, you are correct. I've misremembered the effects. However there are other positive effects from infrared light.In any case, this is just a bonus to the actual purpose of the panels.
Re:Pfizer is testing a pill that, if successful, could cure ... by gytdau on Wednesday April 28, 2021 @07:33AM (#26968192)
I was looking into infrared panels as well, but was slightly worried reading that they may cause your eyes to become cloudy. Is this something you heard of?
Re:Pfizer is testing a pill that, if successful, could cure ... by graeme on Tuesday April 27, 2021 @05:42PM (#26962046)
What did you buy exactly? This sounds interesting but I have never heard of this.
Re:Pfizer is testing a pill that, if successful, could cure ... by sepin4 on Wednesday April 28, 2021 @02:54AM (#26966502)
There are many different manufactures and models. Mine are constructed in Austria. Here are some examples: https://www.redwell.com/en/products/ https://www.sundirect-heater.com/frameless-infrared-panel-he... https://www.heat4all.com/en/products

The cool thing is you can make it part of the interior. I have 3 panels hanging from the ceiling, 1 painting and one mirror. They can be integrated into hanging or floating ceilings and usually have standard dimensions. You have to be aware, that most panels do not have thermostat. They have only one operating mode - On. In order to regulate them, you have to put a thermostat on the electrical line before it(essentially a smart switch). There are thermostats for wall integration. I use those, the cables are hidden in the wall and the actual thermostat is mobile so it can measure temperature at any location in the room. There are also thermostats which are plugged directly on electrical sockets for more integration out of the box. The price is comparable to any other heating solution and the consumption is a little less than air conditioner. Mine came with 5 year warranty. I just hope that they last longer, but with the exception of the painting, all the rest are easily replaceable.

Re:Pfizer is testing a pill that, if successful, could cure ... by carlmr on Tuesday April 27, 2021 @03:07AM (#26952953)
I always see it like this, if it's cold you can put on more clothes (you probably already have them, and they don't waste energy to wear). When it's hot, there's a certain societal lower threshold for what you're allowed to wear in an office (depending on the office shorts are ok, but not less). So you can't individually cool down.
Re:Pfizer is testing a pill that, if successful, could cure ... by dghughes on Tuesday April 27, 2021 @08:12AM (#26954842)
The mantra I've heard is "move heat (energy) don't make it". Don't burn or even use renewable enery to generate heat but move heat already present. Move it away to cool and move it towards somewhere that needs heat.
Re:Pfizer is testing a pill that, if successful, could cure ... by andrewingram on Tuesday April 27, 2021 @07:54AM (#26954704)
Well, jumpers and thick gloves. Due to circulatory issues my hands often turn numb and blue in offices where the AC is cranked up, even if the rest of me is toasty warm.
Re:Pfizer is testing a pill that, if successful, could cure ... by dghughes on Tuesday April 27, 2021 @08:09AM (#26954820)
Maybe you should drink tea. It would warm you up and supposedly tea has mild blood "thinning" properties. You're not supposed to drink tea if you're going to have surgery.

For air conditioning the best part of it is the dehumidifiation. It doesn't need to be arctic cold just the dryer air and a bit of cool is OK.

Re:Pfizer is testing a pill that, if successful, could cure ... by dhekir on Tuesday April 27, 2021 @08:26AM (#26954953)
OP could be referring to Raynaud syndrome (https://en.wikipedia.org/wiki/Raynaud_syndrome). It's not sure tea helps in such cases.
Re:Pfizer is testing a pill that, if successful, could cure ... by dghughes on Wednesday April 28, 2021 @12:26PM (#26971186)
I have Raynaud's disease and cold weather alone isn't a trigger for me unless I am not wearing gloves and if I am holding onto something. A shovel when shovelling snow, or pulling a heavy cart. It has to be a continuous session not just one thing for a few minutes.

I've also been sitting quietly at home and suddenly half my thumb goes purple and the other half is fine.

You know it's Raynaud's syndrome because it feels like someone hit your hand with a hammer. It's not just cold hands it's the pain too.

Re:Pfizer is testing a pill that, if successful, could cure ... by sekh60 on Tuesday April 27, 2021 @12:02PM (#26957752)
Thanks for the link! I had not heard of the syndrome before. but it could be what my wife has been suffering from for the past year or two. We already are waiting to see a specialist to have a look at her, so I won't make any conclusions, but that seems very likely it.
Re:Pfizer is testing a pill that, if successful, could cure ... by datameta on Tuesday April 27, 2021 @11:27AM (#26957234)
As much as I am a huge fan of tea, in this case I think the vasoconstrictive property of caffeine would have the opposite of a therepeutic effect.
Re:Pfizer is testing a pill that, if successful, could cure ... by omegabravo on Tuesday April 27, 2021 @01:13AM (#26952266)
Many* places normally don't have the same temperature since people do wear jumpers in winter and less clothes in summer.

Buildings are often (not always) set to 24-25C in summer, and 21-22C in winter.

*no figures sorry, just in my experience

Re:Pfizer is testing a pill that, if successful, could cure ... by stoolpigeon on Tuesday April 27, 2021 @04:50AM (#26953570)
My wife and I live in Hungary. Every so often we visit Phoenix, AZ in the summer to see family. (My wife is a teacher so it makes sense to go in summer) and the hardest thing for us to do when we go out to eat is finding a restaurant that has seating where we are not freezing cold. It will be 40+ outside and 20 inside.
Re:Pfizer is testing a pill that, if successful, could cure ... by bobthechef on Tuesday April 27, 2021 @07:05AM (#26954354)
Yeah, regrettably, the American practice seems to be to overchill in the summer and overheat in the winter. This is also done in the home to the point that people will wear shorts and tshirt indoors in the winter and warmer in the summer (blankets while watching TV for example). Also office buildings suffer from the same problem. Women usually complain the most about it being too cold (men are more likely to wear suits and generate more great I believe).
Re:Pfizer is testing a pill that, if successful, could cure ... by cma on Tuesday April 27, 2021 @12:27PM (#26958120)
That is probably partly explained by (at least in older houses without reflective insulation) low radiant heat from outside in the winter, and high radiant heat from outside in summer.
Re:Pfizer is testing a pill that, if successful, could cure ... by cma on Tuesday April 27, 2021 @07:53PM (#26963640)
And different humidity explains it some too, even though AC lowers humidity, indoor humidity is still much lower in winter.
Re:Pfizer is testing a pill that, if successful, could cure ... by ghaff on Tuesday April 27, 2021 @07:41AM (#26954615)
I've joked for years that the hotter the place in the US, the colder they keep their AC in the summer.
Re:Pfizer is testing a pill that, if successful, could cure ... by tgb on Tuesday April 27, 2021 @08:28AM (#26954961)
So many times I see the opposite: of its hot out then people crank the AC to coldest setting and if it's cold out then crank the heat up uncomfortably high. It drives me nuts: I don't have an extra layer with me in the summer and I'm freezing in the store/theater/restaurant. I can only hope that this is an American peculiarity.
Re:Pfizer is testing a pill that, if successful, could cure ... by jerf on Tuesday April 27, 2021 @09:01AM (#26955269)
For large spaces there's more considerations than more person-sized spaces. If you make your theater or restaurant comfortable when it's empty and people are walking in, you'll need much bigger AC gear to catch back up once everyone's in there generating heat. It's one of those cases of a problem being quite a bit harder than you might intuitively think because for the most part, engineers have just solved it for you in most spaces, but there are some places where it just gets too hard to fully solve. Variations between locations are probably accounted for in differences in code and how much money there is to spend on the heating and cooling gear, plus how much variation there is in the outdoor weather.

IIRC a person can be approximated as 100 watts of heating. If you add up everyone in the full restaurant or theater you get quite the number for how much heat the people themeselves are putting out.

Re:Pfizer is testing a pill that, if successful, could cure ... by viraptor on Tuesday April 27, 2021 @08:37AM (#26955039)
Singapore has this issue too. Hotel conference rooms (and some offices, I'm told) will be set to 19⁰C or something equally not achievable so AC works full blast, while outside is humid high 30s.
Re:Pfizer is testing a pill that, if successful, could cure ... by throwawayboise on Tuesday April 27, 2021 @02:11AM (#26952593)
At my office the climate control is considered adequate if it is 68 or above in winter, and 78 or cooler in summer.
Re:Pfizer is testing a pill that, if successful, could cure ... by mattowen_uk on Tuesday April 27, 2021 @07:10AM (#26954387)
20 Celsius / 25 Celsius.
Re:Pfizer is testing a pill that, if successful, could cure ... by elzbardico on Tuesday April 27, 2021 @08:13AM (#26954845)
I find anything over 22C too much for intelectual work. So, I am glad I WFH
Re:Pfizer is testing a pill that, if successful, could cure ... by devdas on Wednesday April 28, 2021 @11:07AM (#26970227)
Heh, I find it uncomfortable under 25C.
Re:Pfizer is testing a pill that, if successful, could cure ... by distances on Tuesday April 27, 2021 @12:14PM (#26957934)
Always the same AC fight at the offices, one of the things I don't miss with this work-from-home. My preferred room temperature would be 27C which is obviously a no-go in a shared office, but cooling to 20C in summer is just as crazy too.
Re:Pfizer is testing a pill that, if successful, could cure ... by pfdietz on Monday April 26, 2021 @10:48PM (#26951367)
Counterflow air-to-air heat exchangers mitigate much of that cost.
Re:Pfizer is testing a pill that, if successful, could cure ... by quercusa on Monday April 26, 2021 @11:00PM (#26951464)
I knew about residential ones but it looks like there are commercial ERVs as well: https://www.york.com/commercial-equipment/air-systems/energy...
Re:Pfizer is testing a pill that, if successful, could cure ... by philwelch on Tuesday April 27, 2021 @05:11PM (#26961614)
Submarines tend to operate at CO2 levels around 3500 ppm, and there doesn’t seem to be strong evidence of any cognitive effects.

Infectious disease would be more of a concern, but the submarine itself is a pretty effective quarantine.

Re:Pfizer is testing a pill that, if successful, could cure ... by danans on Tuesday April 27, 2021 @12:56AM (#26952160)
> There are costs, as heat or/AC will have to run more to keep the temperature in the right range.

Heat recovery ventilators can largely solve this problem, while also reducing particulate pollution indoors.

Re:Pfizer is testing a pill that, if successful, could cure ... by melling on Tuesday April 27, 2021 @08:24AM (#26954933)
Interesting, with climate change CO2 will be increasing to over 450 ppm at some point.

Will we have an issue with airborne diseases?

Re:Pfizer is testing a pill that, if successful, could cure ... by graeme on Tuesday April 27, 2021 @08:31AM (#26954986)
No the co2 is a proxy for air exchange with the outside. It is the air exchange that prevents disease, not low CO2.
Re:Pfizer is testing a pill that, if successful, could cure ... by jeremyjh on Monday April 26, 2021 @08:22PM (#26950092)
I assume just installing CO2 scrubbers would have no benefit though, since the CO2 level is just a proxy for how much the air is recirculating.
Re:Pfizer is testing a pill that, if successful, could cure ... by tjmc on Monday April 26, 2021 @09:25PM (#26950652)
HVAC engineer here. Correct - and the reason that ventilation is currently limited in buildings is to reduce energy loss. Exhausting warm air in winter or cool air in summer is enormously resource intensive for a building. Depending on the building configuration, you can reclaim some but not all of that energy by using heat exchangers, where the exhaust and supply air streams exchange heat without mixing but then you impose an energy penalty via increased pressure on the ventilation fans in mild conditions when the heat exchange is of less benefit.

So all the standards and codes are designed around reducing unnecessary ventilation and frankly, there's been very little consideration of the health implications until COVID hit.

Re:Pfizer is testing a pill that, if successful, could cure ... by hvidgaard on Tuesday April 27, 2021 @03:43AM (#26953162)
Modern ventilation hardware can reclaim between 85-95% (claimed, but tested and verified). You do not need to run it full power, just a constant optimized flow and only when people are actually in the rooms. I'm relatively sure that the cost is less than heating/cooling a poorly insulated house.
Re:Pfizer is testing a pill that, if successful, could cure ... by edejong on Tuesday April 27, 2021 @01:10AM (#26952249)
If you would be building a new house and willing to spend double the usual on HVAC, what would your focus be on?
Re:Pfizer is testing a pill that, if successful, could cure ... by tjmc on Tuesday April 27, 2021 @01:57AM (#26952515)
The perhaps non-intuitive answer is - everything that reduces the need for HVAC. I'd be looking at things like passive solar design so windows are shaded in summer but let sunlight in for heat in winter. Very good insulation and building sealing. Double glazing (possibly triple if you're in a very cold climate). Thermal mass in the right places for temperature stablity.

On the HVAC side, you want a system with a high CoP and I'd probably be looking at some form of energy recovery on the ventilation side.

Re:Pfizer is testing a pill that, if successful, could cure ... by eecc on Tuesday April 27, 2021 @03:08AM (#26952962)
Yup, very much so: https://www.treehugger.com/praise-dumb-box-4853131

I live in a relatively new building in NL, where many of these configurations are applied and on its own it won’t go lower than 21C in winter and 25C in summer. Thick walls, thick anhydrous cement floor layer for insulation (although I think it’s also meant to give the option to implement floor heating), _external_ blinds on the South side.

I simply can’t justify a smart thermostat/radiator valve build, despite my inside nerd constantly whispering I should.

Only downside is the heat exchanger air recirculator: it dries the air terribly in winter. You need a humidifier to avoid getting parched skin and mucosa.

Re:Pfizer is testing a pill that, if successful, could cure ... by quercusa on Tuesday April 27, 2021 @10:28AM (#26956320)
> everything that reduces the need for HVAC

This is the answer! Even more important than insulation is air sealing, so you keep the conditioned air inside.

I've learned an enormous amount about building efficiency from

https://www.greenbuildingadvisor.com/ and https://www.energyvanguard.com/

Re:Pfizer is testing a pill that, if successful, could cure ... by graeme on Tuesday April 27, 2021 @08:34AM (#26955008)
What if you wanted good ventilation/co2 levels?
Re:Pfizer is testing a pill that, if successful, could cure ... by maxerickson on Tuesday April 27, 2021 @09:13AM (#26955380)
With modern construction, active ventilation is a requirement. So sizing that for the intended turnover would probably be all you would need to do.
Re:Pfizer is testing a pill that, if successful, could cure ... by hellbannedguy on Tuesday April 27, 2021 @02:57AM (#26952885)
If you are in a temperate climate, like The Bay Area, looking into hydronic heating.

I installed it, and would never go back to forced air. For some reason, it's not popular on the west coast.

It's so simple, a DIY'er could do the instal.

My energy bill is down, and allergies are better.

(I've noticed every store I have been in has forced HVAC, and I have a weird feeling forced air spread viruses. Plus--most retail stores have old systems. They might have slapped in some high mir filters, but I doubt they help with anything on old leaky systems.

(To those interested in hydronic heating, buy Modern Hydronics, by Stegenthal? I'm too lazy to look up his last name, but his book is used as text books.

Re:Pfizer is testing a pill that, if successful, could cure ... by PoignardAzur on Tuesday April 27, 2021 @06:06AM (#26953999)
TIL:

- The term hydronic heating.

- That most Americans don't have hydronic heating.

That's so weird, here in France radiators are just ubiquitous.

This is the detachable showerhead thing all over again. How do you people survive like that? You're supposed to be the highest GDP country in the world!

Re:Pfizer is testing a pill that, if successful, could cure ... by Kihashi on Tuesday April 27, 2021 @09:43AM (#26955699)
You'll find radiators in many older buildings (before about 1930 or so, at least in my area). Some are steam and some are hot water. The problem with them is that they tend to have higher maintenance costs plus if you wanted AC, you'd need to have a separate system, including ductwork. AC is relatively cheap to add to a house with forced air heating and quite expensive to add to a house with radiators. Mini Split AC systems are changing that somewhat, but they haven't caught on too well here.

You can also find baseboard heating, but that tends to be electric and have quite expensive operating costs. It's mostly only used in additions and places where you would only heat the space if you were currently in the room.

> This is the detachable showerhead thing all over again.

Uhhh... Everywhere I've lived in the US has had a detachable showerhead, from places built in the 1890s to places built in the 2000s. It's a normal thing for apartment dwellers to buy a nicer showerhead to replace the likely cheap and crappy one that landlord installed and then put the crappy one back before moving out.

Re:Pfizer is testing a pill that, if successful, could cure ... by kasey_junk on Tuesday April 27, 2021 @07:24AM (#26954484)
It’s because most AC systems require forced air, so hydronic is a second system.

You’ll find hydronics in expensive houses that can justify the double expense or in colder climates where the heating benefits are more important than AC.

Also everyplace I’ve lived in the last 25 years has had detachable showerheads.

Re:Pfizer is testing a pill that, if successful, could cure ... by rocqua on Tuesday April 27, 2021 @04:44AM (#26953527)
For anyone else wondering what hydronic heating is, it's using warm water as your main heat source. Either using radiators, or tubing in the floor to heat a room.

This contrasts against the more common American method of using hot air to heat a home. I believe air heating is more common in the US because AC systems already require the relevant air ducting, so it's easier to install.

Meanwhile here in NL airconditioning is very rare, and 95% of people use a gas fired water heater and metal radidators in rooms for heat distribution.

Re:Pfizer is testing a pill that, if successful, could cure ... by baq on Tuesday April 27, 2021 @07:31AM (#26954541)
i would go as far as to say that nobody in continental europe knows the term 'hydronic', it's just heating, maybe central heating.
Re:Pfizer is testing a pill that, if successful, could cure ... by andredz on Tuesday April 27, 2021 @08:09AM (#26954819)
I looked up the last name: Siegenthaler
Re:Pfizer is testing a pill that, if successful, could cure ... by Robotbeat on Monday April 26, 2021 @08:26PM (#26950130)
Unless you use high quality HEPA filtration (and/or UV sterilization?) as well.
Re:Pfizer is testing a pill that, if successful, could cure ... by SEJeff on Monday April 26, 2021 @11:26PM (#26951646)
You can use ozone generators instead of UV. There is actually a really good residential one that is self cleaning my own HVAC guy recommended.

He recommended I buy it myself on amazon and linked me to a youtube to install it: https://www.iwaveair.com/products/iwave-r

He said that his company would install it, but they'd overcharge and it is easy for anyone to install themselves. He had one in his house and told me all about it like a sales pitch. I installed one not because of the coronavirus, but because it helps with particulates in the air such as pollen and dander, which absolutely wreck me. I've only had it for a year, but it does seem to be noticeably better allergy-wise.

Re:Pfizer is testing a pill that, if successful, could cure ... by myself248 on Monday April 26, 2021 @11:54PM (#26951824)
That one specifically says it ionizes without creating ozone.

That's a good thing, because there is no safe/acceptable level of ozone in indoor air:

https://www.epa.gov/indoor-air-quality-iaq/ozone-generators-...

Ionizing can be a great way to remove fine particulate from the air, but it works best when there are charged surfaces for the charged particles to plate-out on. Simply ionizing them in the ductwork means the particles stick to whatever's handy, which may be the ducts, may be the furniture, may be your lungs.

Which is to say, this product uses a lot of the right vocabulary, to describe precisely the wrong engineering.

Re:Pfizer is testing a pill that, if successful, could cure ... by petre on Monday April 26, 2021 @11:43PM (#26951740)
UVC also generates ozone as a byproduct but it's toxic and it damages the lungs.

https://www.epa.gov/indoor-air-quality-iaq/ozone-generators-...

Do read the warning from the EPA.

Re:Pfizer is testing a pill that, if successful, could cure ... by nibsfive on Monday April 26, 2021 @09:50PM (#26950884)
Yes that increases air quality but it would not add oxygen back into the air in place of CO2.
Re:Pfizer is testing a pill that, if successful, could cure ... by Robotbeat on Tuesday April 27, 2021 @09:58AM (#26955884)
I’ve thought a lot about CO2 scrubbing of indoor air. Oxygen concentrators are cheaper than air scrubbing and much easier to do regeneratively. The simplest and cheapest scrubber is to just use sodalime, but that’s disposable and single-use. A regenerative system that heats up the lime (and vents the CO2 elsewhere) is more complicated and expensive and very energy intensive. Other solutions using amines or other chemicals to remove the oxygen can be more efficient, but many of them don’t work efficiently except at higher CO2 concentrations.

We are, of course, talking about miniaturizing a Direct Air CO2 capture system, which usually operates at large scale to get efficiency. Replaceable cartridges that are regenerated at a central location may be a better option.

But oxygen concentrators are small and cheap and portable and don’t require much energy to operate.

Re:Pfizer is testing a pill that, if successful, could cure ... by gpm on Monday April 26, 2021 @11:18PM (#26951598)
Oxygen depletion doesn't seem to be the issue though, CO2 toxicity does.

At 1400ppm CO2, we've turned what, 1000ppm O2 into CO2 (is it 1-1?), or 1% of the atmosphere. Dropping O2 from (Edit: Fixed numbers) 21% to 20%. Or about a 5% reduction in O2 density. Equivalent to approximately 1500 feet of elevation... That's just not that much.

(There's also a long list of papers showing issues with CO2 toxicity at low levels of CO2... I keep intending to write a blog post summarizing them)

Re:Pfizer is testing a pill that, if successful, could cure ... by taxicabjesus on Tuesday April 27, 2021 @01:00AM (#26952183)
> At 1400ppm CO2, we've turned what, 1000ppm O2 into CO2 (is it 1-1?), or 1% of the atmosphere.

1400ppm is 0.14%. Earth's current atmospheric co2 level is around 400ppm, or 0.04%. While the jump from 0.04% to 0.14% might seem significant (3.5x more co2!), it's not.

Submariners survive on 3400 to 11300 ppm co2, or 0.34 to 1.13%:

> Submarine crew are reported to be the major source of CO2 on board submarines (Crawl 2003). Data collected on nine nuclear-powered ballistic missile submarines indicate an average CO2 concentration of 3,500 ppm with a range of 0-10,600 ppm, and data collected on 10 nuclear-powered attack submarines indicate an average CO2 concentration of 4,100 ppm with a range of 300-11,300 ppm (Hagar 2003). [0]

[0] https://www.nap.edu/read/11170/chapter/5

I'd like to emphasize that the average CO2 concentration for submariners is 4,100 ppm or 0.40%, or ten times Earth's current CO2 level.

Oxygen is much more toxic than small amounts of CO2. Pure CO2 will kill you quickly, pure o2 will kill you slowly.

> (There's also a long list of papers showing issues with CO2 toxicity at low levels of CO2... I keep intending to write a blog post summarizing them)

I'm interested.

Re:Pfizer is testing a pill that, if successful, could cure ... by seunosewa on Tuesday April 27, 2021 @05:42AM (#26953846)
1) How is something that kills you slowly more toxic than something that kills you quickly?

2) Don’t doctors provide severe COVID patients with pure oxygen? If it’s toxic, why would they do that?

3) How does pure oxygen kill you? What’s the mechanism?

Re:Pfizer is testing a pill that, if successful, could cure ... by taxicabjesus on Tuesday April 27, 2021 @10:56AM (#26956756)
> 1) How is something that kills you slowly more toxic than something that kills you quickly?

Pure CO2 will knock you out in 4-6 breaths, and cause your expiration in 10-20 minutes. Laboratory animals are routinely euthanized with co2 [0]. Pure O2 will cause your expiration in 4-6 days through the accumulated damage of reactive oxygen species.

[0] "Expose the animals to CO₂ until complete cessation of breathing is observed for a minimum of 2 minutes (a total of approximately 5 to 10 minutes is usually required)" - https://www.bu.edu/researchsupport/compliance/animal-care/wo...

> 2) Don’t doctors provide severe COVID patients with pure oxygen? If it’s toxic, why would they do that?

This is bad medicine. Early 20th century medical investigators figured out best practices for oxygen support, but the insights got forgotten, now they're just in the old papers in the libraries.

> 3) How does pure oxygen kill you? What’s the mechanism?

tl/dr: Hyperventilation.

Re:Pfizer is testing a pill that, if successful, could cure ... by jsjohnst on Tuesday April 27, 2021 @05:09PM (#26961589)
> How does pure oxygen kill you? What’s the mechanism?

Oxygen is highly toxic to the cells in the human body, but not generally under standard atmospheric pressure. Breath pure oxygen while >33ft below water and you’ll quickly experience oxygen toxicity, ultimately leading to death. Yes, that’s generally specific to divers, but even pure oxygen at standard atmospheric pressure can have health impacts.

More information: https://en.m.wikipedia.org/wiki/Oxygen_toxicity

Re:Pfizer is testing a pill that, if successful, could cure ... by gpm on Tuesday April 27, 2021 @01:49AM (#26952466)
Oops, today really isn't my day for math apparently :(... 1% did seem high.

---

> I'm interested.

Well I don't have a blog post ready to go yet, but I can point you to some papers now.

- This review cites a bunch of papers about health effects in the 1-10k ppm range: https://www.nature.com/articles/s41893-019-0323-1.epdf?refer...

- Table 3 in this paper references a bunch of papers around 10kppm: https://www.researchgate.net/profile/Susan-Rice-3/publicatio...

- These papers show mental effects in the 1-4k ppm range:

https://ehp.niehs.nih.gov/doi/full/10.1289/ehp.1104789

http://www.aretas.ca/sites/default/files/imce_images/Indoor%...

- These two are from nasa about the ISS - which brings it's own complications but otherwise also show mental effects in the above range

https://web.archive.org/web/20190613133240/https://ston.jsc....

https://pubmed.ncbi.nlm.nih.gov/24806559/

Re:Pfizer is testing a pill that, if successful, could cure ... by taxicabjesus on Tuesday April 27, 2021 @06:18PM (#26962561)
Thanks for the links, I have started perusing them.

As someone pointed out in a reply to another comment in this thread, oxygen is especially toxic 33 feet below the surface of the water (because of higher pressure), but can have toxic effects at the surface too. I don't grok respiration yet, but my understanding is that altitude/pressure is essential for putting the relative N2/O2/CO2 partial pressures into context.

Re:Pfizer is testing a pill that, if successful, could cure ... by ddeck on Monday April 26, 2021 @11:49PM (#26951790)
>Dropping O2 from 30% to 29%

Dry air is ~21% oxygen by volume.

Re:Pfizer is testing a pill that, if successful, could cure ... by gpm on Tuesday April 27, 2021 @12:51AM (#26952126)
Ah, oops, you're correct of course. The general point still stands though (at 5% instead of 3% and 1500 feet instead of 1000)

I'm getting the density numbers from here by the way if you want to check the rest of my math: https://www.engineeringtoolbox.com/air-altitude-pressure-d_4...

Re:Pfizer is testing a pill that, if successful, could cure ... by petre on Monday April 26, 2021 @11:51PM (#26951805)
30% O2 in the atmosphere? Mayve when dinosaurs roamed the Earth. We currently have about 21%.
Re:Pfizer is testing a pill that, if successful, could cure ... by Syzygies on Monday April 26, 2021 @08:26PM (#26950126)
Exactly. A proxy.
Re:Pfizer is testing a pill that, if successful, could cure ... by amluto on Monday April 26, 2021 @09:05PM (#26950471)
I have never heard of a building with a CO2 scrubber. Submarines and spacecraft, perhaps.
Re:Pfizer is testing a pill that, if successful, could cure ... by bambax on Tuesday April 27, 2021 @03:06AM (#26952947)
Yes. Or, spend less time inside. That we spend so much time inside is a unique feature of our time, and a very bad one.

Regardless of air or sunshine (which are both extremely important to our physical health), not being outside makes us unhappy. People who work outside often sing while working; when was the last time you heard someone sing in an office.

Re:Pfizer is testing a pill that, if successful, could cure ... by CleaveIt2Beaver on Tuesday April 27, 2021 @09:15AM (#26955401)
There's also a vast difference in the types of work being done outside vs in an office; when was the last time you heard someone sing while documenting code?
Re:Pfizer is testing a pill that, if successful, could cure ... by jgilias on Tuesday April 27, 2021 @08:49AM (#26955158)
People in not too distant future will likely view with envy the readily available fresh air we currently have. Given that in a century or two the CO2 concentration in outside air may reach the 'stuffy classroom' level[1].

Imagine that, having to live and work in oxygenated habitats on our home planet.

https://www.acer-acre.ca/resources/climate-change-in-context...

Re:Pfizer is testing a pill that, if successful, could cure ... by cbm-vic-20 on Tuesday April 27, 2021 @09:02AM (#26955282)
This is a plot element of the movie "Spaceballs".
Re:Pfizer is testing a pill that, if successful, could cure ... by Breza on Saturday May 01, 2021 @07:09PM (#27010752)
I was thinking about that the other day when reading about shortages of medical oxygen in India due to the COVID-19 crisis. That movie picked the plot device because it was so ridiculous and now it could be a real problem in some cases.
Re:Pfizer is testing a pill that, if successful, could cure ... by thepete2 on Monday April 26, 2021 @08:18PM (#26950061)
That's cool and makes total sense as a measure of how "ventilated" a room is, though I'm sure it has its limits.
Re:Pfizer is testing a pill that, if successful, could cure ... by comice on Tuesday April 27, 2021 @06:13AM (#26954040)
I've been wondering about this for a while, do you have a reference?

Do you know how humidity affects transmission?

Pre-pandemic I used to go indoor bouldering where there tends to be a lot of chalk in the air and I was curious how that affects transmission. Couldn't decide if the dryer air meant less transmission, or the larger particles meant more maybe. Couldn't find anything about it.

Re:Pfizer is testing a pill that, if successful, could cure ... by karmelapple on Tuesday April 27, 2021 @10:51PM (#26964934)
Re:Pfizer is testing a pill that, if successful, could cure ... by karmelapple on Tuesday April 27, 2021 @10:50PM (#26964930)
In case anyone is looking for a citation, here’s a recent peer reviewed study of a Taiwan university and how increasing ventilation greatly reduced tuberculosis infections.

https://onlinelibrary.wiley.com/doi/full/10.1111/ina.12639

Re:Pfizer is testing a pill that, if successful, could cure ... by a_f on Tuesday April 27, 2021 @07:35AM (#26954562)
Any evidence for this?
Re:Pfizer is testing a pill that, if successful, could cure ... by karmelapple on Tuesday April 27, 2021 @10:49PM (#26964926)
Re:Pfizer is testing a pill that, if successful, could cure ... by JshWright on Tuesday April 27, 2021 @07:49AM (#26954667)
The point here isn't that CO2 matters. The CO2 is just a marker for adequate ventilation (and there is plenty of evidence that ventilation is very important in reducing transmission).
Re:Pfizer is testing a pill that, if successful, could cure ... by simonebrunozzi on Thursday April 29, 2021 @03:27PM (#26985476)
Any source for this claim? (I kind of trust you, just wondering if you have a specific source to offer)