I subjectively noticed that a "stale office building" environment prevents my thinking, while a breeze in the open air is more intellectually stimulating.
My office building is clearly capacity-planned for cubicles. As we pack it denser and denser, the overload shows up in obvious places: elevators, bathrooms, cafeterias, parking. But I bet we are also overtaxing the air handlers. Might help explain why it feels so much more stifling now.
Funny. I feel weird for saying I can't be in our Quiet Rooms for long. They have no ventilation. They are tiny. I start to feel sick and exhausted if I am in there too long. Some people have groups of three meetings in there for hours! How do they not pass out?
Another interesting topic is the movement's impact on steam heating capacity in the skyscrapers from the era. Has lasting effects to this day because of overcapacity.
I own a CO2 monitor and it is shocking how high it can get in a house with two people just existing. 800 ppm or more. Outside air is 410.
In a car with air on recirculate, it was getting to >1220 ppm, a level that impairs decision making and lowers brain function. I try to drive with air on fresh from now on.
I don’t doubt the air in our conference room with 20 people gets super high in CO2 as the meeting goes on, and that would explain a lot of the horrible decisions and thought processes that happen in there. :) I’m going to bring my meter to the next meeting and see what it gets to. We are a group of scientists so it won’t be awkward or weird. If nothing else it will spark discussion and reflection on the decisions that are made there.
It has an app (and an API) and monitors CO2, humidity, temp, and VOCs. I like it a lot. For me, it mostly serves as a reminder to open the door for a few minutes before bed and let some fresh air in.
I'd love a good looking consumer device like this, especially if it synced with Apple Health and/or Homekit or otherwise allowed data export, but all (Netatomo, Awair, Uhoo, etc) seem to get very poor reviews on Amazon, often claiming they are inaccurate. Has anyone seen a good comparison of whats out there with a suggestion for the best?
I can also recommend that talk and the Awair unit seems to live up to the praise. I know some might suspect shilling by DHH for this product, but given I owe the last 10 years of my career to him, when he speaks I listen a bit closer than normal.
I got it to monitor CO2 levels in a house without central air. It's pretty amazing how quickly it rises without the air on or a window open. If the air in a room feels "stuffy", it's probably over 1000 ppm.
It says the CO2 range is from 0-5000 ppm, but exhaled breath has a much higher concentration (according to another comment). Are you able to accurately measure the inhaled concentration in case the breathing happens in a confined space (e.g. helmet or under a blanket, etc.)
in the unlikely event someone manages to shove that thing inside of their helmet, do they _need_ an accurate measurement? if it hits 5000, it can just be read as "way too much".
I have been considering making a CO2 sensor myself using commercially available CO2 detectors [1] , [2] and an Arduino or similar microcontroller, insructions for which abound on the intertubes [3], [4]. Such a device can be made fairly inexpensively.
However, there is a known issue in calibrating the device, as the IR emitter and light sensor change characteristics over time. The calibration requires immersing the device in nitrogen or pure CO2 and is costly and complex. The workaround is to calibrate the device outdoors where there is an assumed 400 ppm CO2.
I believe you can hook it up to IFTTT and turn on the AC etc if levels are high. You can get real time stats, historical reporting...If you don't want to keep looking at your mobile device it will light up if the air quality is bad.
It also has a VOC monitor, which is rare. I have a new construction house and the VOC was pretty much deadly.
Far too many to be plausible. You'd need to live in a terrarium. Which would certainly be nice, but it's a lot of maintenance...
There are plants that do pretty well at air filtering, though not as well as a HEPA filter... but for CO2, they won't absorb more than they can use. This means you need dozens, and also that you'd need grow lights to keep them photosynthesizing as fast as possible.
I've seen an office that was built like that, and it was actually a very nice experience. The owner enjoys spending as hour gardening each evening, though, which is important.
Depends on the plant and other aspects of the environment, and actual numbers are hard to find. Also, you need the plants to actively be growing; their steady-state metabolism just temporarily captures carbon and then releases it again.
A typical person exhales just over 1kg of CO2 daily. You'd need emough plants to fix about the same amount of CO2 from the air, under indoor, shaded conditions.
The fastest rate of carbon fixation by any plants are photosynthetic algae eds, which fix u to 4.4 kg of carbon per square meter per year, or 16.3kg CO2/(m^2 * yr).
The source you're citing talks about 4.4 kg estimated per m^2 for algae in the open ocean, and notes that the maximum known rate is 9.16, so around 9 * (44/12) = 33 kg per m^2/yr converting C to CO^2, or around 11 square meters.
In terms of CO^2 sequestration it doesn't seem implausible to fit a farm of that area in something the size of an apartment..
Of course the energy/water use would be insane, hopefully you could funnel sunlight in, or just open the window. But as a thought experiment that ignores the economics of it think more space station than apartment.
Critically, you need on the order of N m^2 of sunlit area on your culture, not N m^2 of floor space. If you image search "phytoplankton culture" you can see that people grow these in bottles or thin plastic bags under artificial lighting, maximizing the surface area.
You can easily fit 11 m^2 in one square meter like that under standard 250 cm ceiling height. Just have a stack every 20 cm.
Note that the article refers to both carbon and carbon dioxide fixation. CO2 weighs more than the carbon it contains, by a lot. Carbon has an atomic weight of 12, CO2 a molecular weight of 44 (12 + 216), or just shy 4x the mass of the carbon* component of CO2.
The 4.4 kg I gave was carbon, the 16.3 kg CO2. Your 9.16 kg refers to CO2, fixed per square meter per year, which is less than the CO2 fixation value I'd used. That is, http://carbon.ycombinator.com are making a more conservative estimate of about 56% the maximum observed rate. That increases rather than decreases the required area.
At 9.63 kg/(m^2yr) you'd need 39.8 m^2, or 429 ft^2, of algae to offset one person's CO2 exhalation.
Using GNU units:
You have: (1kg/day)/(9.16 kg/(m^2*yr))
You want: m^2
* 39.873602
/ 0.025079249
You have: (1kg/day)/(9.16 kg/(m^2*yr))
You want: ft^2
* 429.19589
/ 0.0023299385
You have: 9.16/16.3
You want: %
* 56.196319
/ 0.01779476
Apologies for typos in GP post. Android soft-keyboard stinks.
I understand the difference, but perhaps I misunderstood the article. What it says (and you're correctly referring to) is:
> We will be conservative and say that our algal beds fix 2.5 kg of C per square meter per year and 2.5 kg of C works out to 9.167 kg of CO2.
But then a couple of paragraphs later:
> the maximum CO2 assimilation rate of algal beds which we will say is 9.167 kg of C per square meter per year.
I.e. they first mention a conservative "2.5 kg of C" in the context of the ocean, followed by a "maximum rate". 9 kg of carbon is around 33 kg of CO^2.
Maybe they meant "kg of CO2" in that second paragraph, it's certainly suspicious that it repeats the same 9.167 number, but why would they call that number both "conservative" and "maximum assimilation rate", hrm...
It's far more than you could ever plant, I suspect. I've been in legal marijuana grows in houses where it is nearly wall to wall massive growing plants under many 1000W bulbs and the CO2 still goes up when people go in the house and start breathing and moving around.
When we see science fiction movies and there is a tiny little area with plants that is supposed to be providing the multi-person crew with CO2 scrubbing and O2 generation, I think the size needed is vastly underestimated.
>A human breathes about 9.5 tonnes of air in a year, but oxygen only makes up about 23 percent of that air, by mass, and we only extract a little over a third of the oxygen from each breath. That works out to a total of about 740kg of oxygen per year. Which is, very roughly, seven or eight trees' worth.
To get an idea of what you need check out the Biodome and Biodome II projects. They were massive structures chock full of plants to sustain a small handful of people, and it wasn't enough.
Some is definitely better than none for more reasons than just air scrubbing, but I believe one of the sibling comments stating “too many to be practical” is probably (and unfortunately) correct
Also don’t take my word for it, but I remember reading that the viney/dangley kind are better than average for certain pollutants (and they just look really nice dangling from a ledge or window sill)
How does air recirculation with increasing co2 compare to having to breath/smell car exhaust, cigarette smoke, etc through vents? I started doing recirculation as my default years ago due to that.
You don't need fresh on all the time, but for long trips I will switch to fresh for at least five minutes each hour. You just want to cycle the air in the cabin for less re-breathed air.
This is almost certainly correct. An unventilated space as small as a car will increase within 30-60 seconds, based on my testing of small indoor rooms.
Generally, use recirc only briefly when driving through heavy exhaust, smoke, dust, chemicals, smells. Return to fresh air once you've cleared that.
Some sources suggest recirc for heavy traffic -- I'd prefer a good filtration system.
And for rapidly heating or cooling a car, recirc can help. My preference is to open windows & sunroof (where present) to flush out hot air first, in hot weather. In cold weather, the heater won't kick in until the engine has warmed up, so recirc before that buys you little. And recirc + heat can result in fogged windows, so you may want to turn in the AC as well to rduce humidity. (Many cars now activate AC when defrost is selected.)
I rarely keep recirculated air set for more than a minute or two, most often far less.
Fresh just doesn't work well enough compared to recirculated for me. If the car isn't getting cold enough, recirculation being off is always the culprit.
I've questioned why fresh is even there (seems unlikely co2 would be the reason) - it's always going to be less efficient and you can open a window if you want fresh air.
Anecdotally I feel fine driving for 2 hours straight in recirculated air with closed windows.
Fresh is there at least partly because cars didn't used to have AC. If you are driving in-town or stop-and-go having a fan on your face with fresh air takes a bit of the edge off.
Also in heating mode, there's little reason not to use fresh, as we can heat up cars really easily.
Cars are built to mostly recirculate the cabin air when the recirculate option is turned on. Note that cabins are not fully sealed from the outside. You have multiple vents located throughout the car whose job is to keep the outside elements away and let the cabin "breathe".
Leave it on recirculate unless you are defrosting your windows.
Apparently there was a fad for building schools with no windows. There's a 70s era middle school in the (U.S.) town where I live; it won a design award for its total lack of fenestration. It was supposed to reduce distraction or something.
My schools were all like that. "Kids aren't paying attention to our standardized-test preparation studies! Perhaps we should make schools more like bleak prisons, and force people to spend the bulk of their formative years there! That will certainly result in a more capable general populace."
My HS in central NJ had neither windows in the classrooms, nor WALLS. It was designed like a giant open office bullpen thing and classes were supposed to congregate in vaguely defined areas. By the time I got there in the early 90s, they had already erected borders everywhere out of movable chalkboards, so you basically got a traditional classroom layout but with noise pollution from all the other classes going on nearby. Great job all around. (Though I suppose from the CO2 standpoint we were probably doing better than most!)
The walls were part of a new teaching fad. I lived in a city that tried it out in one school. Each floor was an open plan for the classrooms. This one elementary school was their trial.
The teachers had a love/hate relationship with this plan.
My senior year, the high school installed blowers in each classroom. We were told it was required by a new California law.
I’m not sure it was an improvement: the blowers were noisy and made the classrooms much less comfortable (colder in winter, warmer in summer; it was an older school and the HVAC systems weren’t great). Teachers constantly talked about how they wanted to destroy the blowers. I seriously doubt grades improved. I wonder how previous students managed before our enlightened times.
Buildings used to be much draughtier, so it wasn't so much an issue.
My landlord at my old place was always adding new insulation. Co2 levels there would get really high with windows shut. My new apartment has much lower ambient co2. Both were built 100 years ago.
I think people also used to leave windows open a bit, even in winter. My (Canadian) grandma always did, and I hear it was the custom in Germany.
Modern buildings are made to be hermetically sealed.
At least when I went to school it was almost impossible to keep a window open except on the hottest days of summers because inevitably n>1 [almost always] girls would start to complain about draft. (edit: is draft in a room with only one opening to the outside a social construct?)
That being said I always keep the window open in my office. There is no draft.
When I was in elementary school, one of my classmates ended up missing school for a while because of a bad heater and carbon monoxide poisoning. That freaked me out. But everything I read was that this was a relatively new problem because newer houses were less drafty than old houses. It wasn’t clear to me (at the time) whether old houses were draftier when built, although I have to assume they were (otherwise carbon monoxide poisoning would have been just as common when those houses were new).
I even remember wearing sweaters indoors when I was young. I assumed that was an effort to save money during the so-called Energy Crisis (better described as a shortage of cheap oil), but it may have just been the natural reaction to inefficient heaters and the building standards at the time.
Yes, building standards have changed dramatically in the last 50 years. In particular, plastic "house wrap" vapor barriers are standard now, which is a product that had be precedent. There is a tremendous amount of air exchange even through a well-built 'solid' wall with no vapor barrier.
Definitely true. You can measure how leaky a building is by sealing it up, blowing air in the door, and measuring how the pressure changes. If it’s very leaky the pressure doesn’t rise as much.
We used to assume that you’d get enough fresh air from infiltration through accidental sources. With a better sealed building, that’s not always the case and you may need to deliberately bring in outside air. Heat recovery ventilation systems help to do this more efficiently than the inadvertent leaking method.
Thanks. I really hope hrv systems become standard. My brother has one in his house and it seems to help keep down co2.
Do heat pumps ventilate? I have one in my new apartment and co2 seemed higher when it was off. But I was told they are not hrv systems. Maybe the blowing fan just caused more air circulation.
At least here in BC, I believe it is code to include a fresh air vent with any central HVAC. Our house has one (built in 1992). Of course, if the house is tightly sealed and you don't have an exhaust fan running, it won't suck in much outside air.
Since the climate is moderate where we live, what's been suggested to me is to just run the recirculate fan often/always, and to use bathroom exhaust fans to control fresh air turnover. (As built our bathroom fans are hooked up to a central humidity sensor, and will turn on when house humidity reaches a set level (as well as being able to turn them on in the bathrooms). I'm actually curious whether something exists, or I could rig something up, to turn them on based on CO2 levels as well.
HRVs also let you control where the fresh air comes in and where the stale air leaves. This means you can do clever things like bringing fresh air into bedrooms and removing air from bathrooms.
Maybe this is a tradeoff people need to consider when trying to reduce their wasted energy in buildings. Maybe try to do some kind of heat exchange in the air exchange?
I know of at least one case where a family was killed because they were using a laser cutter on wood indoors in a well sealed building and the small levels of CO released were able to build up to lethal levels.
I ran a CO2 monitor in my classroom and found it exceeded 2000ppm on some occasions. Typically it would be 1200-1600. I discussed this with architects when building a new facility, and the new facility tests at <900ppm fully occupied.
I think the high levels before led to worse behavior and lower academic performance. Both seem generally better now.
800ppm is a fairly typical value for indoor CO2 and not really that shocking.
Fun fact: We've known since ~1850[1] that we should probably stay below 1000ppm for indoors, but we based the measure back then on body odor :) (It still bugs me that oddly cognitive impairment starts at the same point a body-odor measure from the 1800s put CO2 levels, and I keep wondering if we're seeing confirmation bias in action)
In general, where you end up is based on airflow. To get below 800ppm, you'll probably need to increase outside ventilation to >10dm^3/s.
[1] von Pettenkofer, "Ueber den Luftwechsel in Wohngebaeuden"
Fascinating. If you were a fan of evolutionary origin stories, you could easily imagine that the negative association with body odor is an evolved "canary in the coal mine" mechanism. That is, once you start being irritated by your cave-mates BO, it's time to step outside for some fresh air (before you are asphyxiated).
That said, I doubt humanity spent enough time in caves or other restricted airflow environments for such a response to evolve...
Additionally, to support the idea that we evolved to detect and dislike body odor, you'd have to make sure that humans even have this trait. Too many evolutionary just-so stories generate hypotheses from limited cultural observations.
This article about one of the few remaining hunter-gatherer people left, the Hadza, might lead you to question the idea that humans have a "dislike body odor" trait:
> While Hadza have a word for body odor, the men tell me that they prefer their women not to bathe—the longer they go between baths, they say, the more attractive they are. Nduku, my Hadza language teacher, said she sometimes waits months between baths, though she can't understand why her husband wants her that way.
I would be interested to see if increased levels of CO2 alter our perceptions of smells/odors. It may become more unpleasant to encourage us to vacate the poorly ventilated area.
I picked up a CO2 monitor a while ago myself, and the biggest surprise was having it on in the morning in our bedroom with the doors closed. It was easily over 1000ppm IIRC.
Ever since then I've made sure to set my AC system to run the "house fan" for 15 minutes or so every hour at night just to circulate the air in the house, and while the numbers went down significantly, anecdotally I swear that I wake up easier in the mornings now.
Another surprising place that really high CO2 concentrations show up? The inside of full face motorcycle helmets when at a stop. IIRC they quickly reach as high as 20,000ppm! There is also some speculation that full-face motorcycle helmets that stay closed in an accident are more dangerous in some ways, as the high CO2 concentrations in the helmet can be really dangerous to an unconscious person's brain function.
Helmets? That's interesting; I tend to open the visor a bit when at a stop, it gets really warm in there really fast. I know you shouldn't try to take off a helmet in case of an accident, but is opening the visor at least okay?
Yeah ever since I read that, I crack the visor or open it when i'm sitting still.
And for opening the visor in accidents, I'm no expert but I believe it would be safe to do if you can do it without moving their head. IIRC the reason you don't want to take off the helmet is because you could strain their neck doing so. If you could move the visor without moving their head, it probably won't hurt, but at the same time I'm not sure if I'd worry about that in this kind of situation (having seen a motorcycle accident, the amount of co2 that person is breathing is, to me anyway, far down the list behind "call 911" and "make sure they don't get run over again").
I think the findings were more to try and get the helmet manufacturers to design systems which let more air in during an accident or when stopped.
[1] has the study I remember reading about, and it turns out that according to their abstract, opening the visor at a stop has little effect on average! So maybe my behaviour of cracking the visor isn't doing much...
Moving an unconscious person's head or neck can cause paralysis (if they have a spinal injury). Don't do it without training. In a city it's almost surely best just to wait for the EMTs.
Unless it is terribly cold, I always run a small crack at low speeds. My helmet has a notch that is just a half inch of crack. At high speeds the vents pull air through. It is funny because I never thought about CO2, just that it is too freaking hot.
> I know you shouldn't try to take off a helmet in case of an accident,
At least here in Germany this advice is considered outdated and people in (mandatory for driving) first aid courses get taught a simple technique to remove a helmet safely (ideally with two people).
Reason being is that with the helmet on it is harder to monitor breathing and impossible / very difficult to do CPR, and the helmet will also interfere with the stable side position.
It’s interesting to see how differently first aid is taught across countries. Eg the last training I did in the US (California), I was surprised by two things that I had not encountered when I was trained in France:
- a big concern around pathogens - always have gloves with you and put them on when administering first aid especially if the person is bleeding; use a mouth dam for mouth to mouth and if you don’t have one don’t do mouth to mouth, just chest compressions, etc
- training first aid responders around what to do when a person needing medical attention tells them not to help because they don’t have health insurance (this point was repeated numerous times by the EMT training us, saying it was routine for them to have to deal with it)
If the person is able to tell you that they have no insurance, this by itself means they're able to talk reasonably, this means they are conscious and can breathe and so (absent heavy ongoing bleeding e.g. from a gunshot wound) they aren't dying right now - so urgent emergency healthcare isn't really required.
If they can move on their own, then they can get to the clinic of their choice themselves if and when they choose to; if they can't (which can be caused by anything from a sprained ankle to a fractured hip) then they still may prefer to be delivered to the hospital by family&friends or a taxi instead of paying thousands for an ambulance delivery.
good point about using that as an assessment of the persons state of being. they still could be bleeding however which needs to be stopped unless it's just surface scratches, or have broken bones that need temporary stabilizing.
it seems other than for the first point the question only becomes relevant after any relevant first-aid actions are completed.
i have been in a situation where a guy fell out of his wheelchair. he wasn't injured, he just could not get back into his wheelchair and he was to heavy for any of us to help him without us risking to drop him in the process which might have then actually risked an injury. he looked like the kind of person who might not have had insurance. though he didn't make any statement about that and no-one even considered that to be an issue. we saw no choice but to call 911, which sent an ambulance with people who could help (and they knew him too).
i wonder now how we would have reacted if he had told us that he has no insurance. we might have been looking for alternative help with an outcome that could have been good or bad.
with that in mind i'd think other than for the reasons you mentioned the statement should be ignored.
Can you expand on your second point, if you have a moment?
I knew someone (in California) who crashed his bicycle on a curb in front of a number of people. He picked himself up and had a bloody but minor wound on his arm. But overall he was unharmed, just some surface bleeding.
"Of course" multiple people called 911, and an ambulance arrived in short order. He had insurance, but he wasn't interested in getting in an ambulance, he wanted to look after his bike while wrapping up his light wound, and then treating it later.
I'm told the exchange was awkward to say the least.
Interesting. I'm an American, and once sustained a bloody but minor scrape of my knee when playing basketball in China. I went to the campus clinic/dispensary to obtain some bandages, since I couldn't find any that were the right size at the nearby convenience store; there, the staff practically tried to admit me, telling me that I had sustained a very serious injury and that I needed to take it seriously and start a course of antibiotics. After an awkward conversation concerning my refusal to take antibiotics without (what I deemed to be) sufficient cause (being mindful and wary of the resistance risks of an unnecessary course), and their belief that I was being disrespectful of their medical expertise, I left with a bottle of antibiotic pills that I never took. My knee was as good as new in a week or so.
Point being, medical cultures can differ quite a lot, even from locality to locality, and the differences can be seen even in the handling of minor scrapes.
Correct me if I'm wrong: I think that a wound that is bleeding is a wound that's, at least in part, being protected from infection by 'internal positive pressure'.
My grandpa taught me that; to let wounds bleed freely for a while, if possible, to reduce the chance of infection.
The most surprising things I was taught when taking classes in Germany (which went beyond the mandatory classes you have to take to get a driver's license) are the following. Well, not really surprising once you think about it...
- Mouth-to-nose is usually better than mouth-to-mouth, at least when there is no obstructions (like bleeding, broken nose, snot, etc).
- If you're doing chest compressions, expect a high probability of breaking a few ribs. Don't stop, as it is highly unlikely the ribs will break "inwards" and puncture a lung, and a broken rib is still better than being dead.
- Remove all clothing from the chest area you're working during CPR. Yes, that includes bras, specifically. The reason being that any clothes will hurt your hands/rip your gloves (if you have some)/shave the skin off your hand especially when you have to do CPR for 15mins. Bras in particular often have wires etc in them that will hurt your hands even worse. As one of the EMTs training us put it: "Don't be shy, no time for false modesty, it may cost a life."
- Don't forget to breath when giving mouth-to-*. Also, don't forget to actually lift your head when you breath. Else you will just breath in the spent air again that you and the person you're helping just exhaled. Given that CPR is very physically taxing, according to the EMTs it is quite common for people giving the CPR to faint themselves if they breath incorrectly.
- It is more important to call for help than to do CPR. Always call first, if you're alone. And stay on the phone until you're being told you can get off the line. Apparently a lot of people either do not call, or call, scream some stuff into the phone, then hang up to administer help, often forgetting to tell crucial details like their location because it is such a high stress situation.
- Defibrillators do not actually restart hearts that stopped beating. They essentially stop the heart in order to reboot it in hopes it will restart with a proper pace/rhythm.
It's not usually taught, I think, because if you dony have a knife (which is what professional rescuers will use if they need to do this), removing clothes tends to add delay and also involve moving the subject, both of which are strongly contraindicated in most circumstances where a lay rescuers needs to use CPR in the first place.
The man has a pretty good explanation in that case, iff there was a good reason to administer CPR. So what would it cost the rescuer, exactly? Unless you start undressing every unconscious woman you encounter, even if they seem to have no other problems...
People have been sued for injuries caused while performing CPR, so I could certainly imagine someone being sued for undressing a person (without their consent, obviously) to perform CPR.
Do you have a link for that? Every time I look into one of these/similar stories it is a shitty insurance company either heavily encouraging or basically forcing the suit if the person wants to be covered for their injuries at all.
You can sue anyone for just about anything. But it doesn't seem like a very winnable case to me. Maybe in some crazy jurisdictions. Many places have 'good Samaritan' laws that protect people who are not medical professionals when they cause injuries during a good faith attempt to safe someone's life. I would assume injuries to someone's modesty are included...
At the end of the day, would you rather let a woman in need of CPR die because you are afraid of maybe getting sued, with an even smaller chance of a conviction?
There's also the court of public opinion to consider, in which actual legal standing is irrelevant. Small comfort if you successfully rebuff a suit but lose your reputation in the process.
In Germany not performing what we call "lebensrettende Sofortmaßnahmen" (stable side position, clearing airways, CPR) is (at least technically) criminally liable to § 323c StGB. I shall also point out that first responders have some legal protections and insurance.
This should not happen. Another rule is that you must not to put yourself on top of the victim or walk crossing over the body of other people. Is disrespectful and can be dangerous also. You have to sidestep it and approach from one of the sides.
I understand how social rules about touching other people can differ in different cultures, but a side position looks clearly different to a "riding" position to me in this sense.
People feel often ashamed, can feel humiliated, violated, happy, sad, or anything their want, but they have to understand that CPR means that 1) you life is at risk and 2) some stranger(s) will put their mouth in yours and their hands near your breasts for some time. Period of time that can last for many minutes or even hours. Often longer than the duration of most violations. There is often a legal obligation to do it for some people. To pass and quit the area is not an option.
Sorry but there is no time to find a young sexually acceptable partner for you to happily wake up in her/his arms and upload your booze adventure to instagram, forever-happy style. Deal with it. There is nothing sexually arousing in the experience for the rescuers about your vomit taste or about your body leaking different kinds of fluids over yourself. Not even remotely.
I used to ride with a just-a-bit opened visor because it was so hot in the city, with all the traffic and all, (and the beard didn't help the air flow) so I ended with eye infection because of the dust ingress. So I just bought one with better vents (and audio). Worth every $ even though I had to patch the audio circuitry a bit.
Yeah I always open my visor when I'm stopped/riding slowly for longer than I can comfortably hold my breath. Depending on the temperature outside, if I don't open my visor it will fog up real fast.
Exhaled breath is about 3.8% or 38000ppm so (20000) that's really high! I'm not too surprised since the turnover rate through a few small holes with a relatively large volume is bad. Reducing the facial volume would help a lot as each breath would expel more CO2 as a fractional percentage.
It seems that any sort of face covering or even significant exercise could raise your ambient CO2 level well above 1000ppm.
I'm a bit surprised that levels 38-60x below our exhalation % (and it's not lack of O2, because you use up less than 10%/breath) has such a significant effect. The one thing that may drive it is that the efficiency of lung ab/desorption goes roughly as the square of concentration so a 2% change in CO2 concentration might be enough to have an effect on O2 and blood pH.
Really interesting article... all the numbers are completely believable, but seem really high based on the conference room effects at 0.1% They even refer to a person without a helmet in still air as being at 2000ppm, which is comparable to the worst tested "school house" data.
I'd argue that if there is an effect here it isn't the O2 concentration since a 1% change in atmospheric pressure happens at about 275ft. That's a pretty small hill!
A 1000ppm change in 02 partial pressure happens in about 30C temperature change. Really, if this is a real effect it better be actually due to some effect of C02 concentration.
I wonder what the number is for people who wear respirators for dust/fumes. There's the paper masks people are most familiar with and the charcoal canisters for working with chemicals. Since it's sealed off would it be even higher than a motorcycle helmet?
There’s probably all kinds of confounding factors here, but on high pollution days (code purple air quality) when I’m bicycling I need to take my N95 mask off every few minutes for “fresh air.”
> "house fan" for 15 minutes or so every hour at night just to circulate the air in the house,
Depending on your climate, this could significantly raise the humidity in your house. Reason is that moisture from the AC coil are wet after the AC turns off. Typically drips off into the pan until next time AC cycles.
If you run the fan you will then evaporate into the air circulating some of the moisture just removed.
I live in florida, so I'm well accustomed to the humidity! But thanks for the tip, I actually hadn't thought about that.
Part of my home automation system is humidity sensors as well, and while they do spike over 65% sometimes (probably when we have the windows open), they stay around 55% to 60% for the past 30 days. Since I'm only running that fan cycle at night, when the AC tends not to run or not run as much, I'm guessing that helps mitigate the effects of that.
Doesn't that heavily depend on the design of the AC system? I know nothing here, so this is heavily a question.
I ask because I have a heat pump for cooling/heating, but the furnace is the blower. I thought when the fan ran, it pulled from the outdoor intake which is in a very different location from the actual heat pump coils.
that moisture came from inside the house. When it drips, it usually drains outside the home. Perhaps it just pedantic, but it won't raise humidity, but it may lower less.
I monitored the CO2 in my bedroom every second for three months and I found results similar to you. If I was sitting right next to the sensor in the evening it would go up to about 1900 ppm. Cracking open the window for an hour or so eventually brought things down to the 500ppm range.
What was interesting is how fast the ppm increases when someone enters the room. I would plot the data and see a blip on the graph when I entered. It was within seconds of entering.
I noticed the same when I am sitting near the sensor. I'm thinking though that it is partially due to me essentially breathing onto the sensor and the sensor dynamics having an averaging function so that I'm not sure what the sensor reports and what I breathe in are the same. Repositioning the sensor so it wasn't in the "line of sight" of my breath changed the readings significantly.
Your post has made me consider getting a C02 monitor, will something as simple as this 20 buck Chinese version suffice? https://www.newegg.com/Product/Product.aspx?Item=9SIADJN8NP4...
Seems a useful thing to have. Separately it is very stressful being on stage at conferences that are stuffy with no fresh air, hot stage lights and probably very low oxygen. I had a friend who did press ups before going on stage to energize herself as the tech conference chair and raise the energy level of the sleepy audience - she got really out of breath!
IIRC the thing to be aware of is that a monitor that actually measures CO2 is going to cost several hundred dollars. The cheap ones don't measure CO2, but some kind of VOC as a proxy. So depending on the source of the CO2, they can be more or less accurate.
Something to research. I'm not an expert, just someone who recently did some shopping for CO2 monitors for my home.
I didn't. Part of my requirements are that I can tie the device into my home automation. After doing a lot of digging and not finding something I wanted, I shelved the idea of adding CO2 sensors to my house for now. Decided instead to just assume CO2 was high, and I'm having a whole-house HRV installed in a few months.
I can't see that link (it says the product ID is invalid), but I know that measuring CO2 is actually pretty hard and requires some somewhat expensive stuff, but measuring things like O2 is easy (i believe, i'm going from memory here).
So most cheap CO2 monitors are actually just oxygen monitors that aren't actually measuring the CO2 levels but are measuring the drop in O2 levels and extrapolating from there.
I don't know if that matters for what you might want to use them for, but it's something to be aware of.
I don't have mine any more, I actually borrowed it from a friend and it was a fairly expensive one (like in the $200 range) that he was using for some other stuff.
> I picked up a CO2 monitor a while ago myself, and the biggest surprise was having it on in the morning in our bedroom with the doors closed. It was easily over 1000ppm IIRC.
It's a greenhouse CO2 monitor, which is the most common kind. I've heard that they're not as accurate as CO2 monitors that are designed for humans, but those tend to be much more expensive.
I always sleep with the window open, because the fresh air feels nice.
In evolutionary terms, you could speculate that the nice feeling of fresh air could be an instinctual response directing the organism to seek higher quality air.
I did quite a lot of research trying to find the best CO2 sensor that would also do humidity/temperature. CaDi by nuwave* is what I settled on. An Irish company. I've been using it for a week now and it is working great! Things that surprised me: the difference it makes if I leave all the internal doors open in the apartment, not just the bedroom door. That even leaving one window open just a crack will help with ventilation. And of course how quickly a room with couple of people in it can go above 3000ppm CO2.
As a full face helmet proponent and user (since I started riding motorcycles in India), your comment really makes sense.
This is something I used to do almost on instinct,usually at lower speeds (because the helmet had a sort of an intake and a vent that worked well at higher speeds).
I have an awair and I’m very happy with it. I have done some highly unscientific testing with it and it seems to definitely register spikes on all sensors when inundated with a given pollutant
If you're in a heavily trafficked road, particulate matter from other vehicles' exhaust is a far worse threat than elevated co2. Always recirculate on the highway, especially if you sit on it for multiple hours a day for you commute.
there's a podcast Ashes Ashes (07 - "Last Gasp") that did a whole episode on CO2 and the studies that track the various effects on our health depending on how high the ppm gets. Apparently has a big impact on cognition, and they made the point that all of civilization could be dumber because of base CO2.
It might not last long, but it might also lead to bad decisions based off of discomfort alone. Or distractions if someone's shirt is too thin for the rain.
Once you have an umbrella and decent enough temperatures (and/or proper clothing), the effect is lost.
Is one person, or two in a closed room overnight the same, or similar to a conference room with say, 15-20 people for several hours? My apologies if you addressed this.
Not sure what CO2 levels that would generate - you'd need to measure to be sure. But my calculations suggest that effects are negligible even up to ~5000 ppm, and many of these studies are boohooing about 1-2000ppm conditions.
I do think this area is understudied. It's just that being afraid of the air supply is such an easy way to nocebo yourself.
The lowest number this article talks about being bad is 945ppm. A ppm of 600 is discussed as "fairly low" co2 levels. They are clearly not boohooing over the entire range of 1-2000.
If you prove that, in theory, the results you observe shouldn't occur this usually means you're using the wrong theory. In your case you're not looking at the differential binding of oxygen and carbon dioxide to hemoglobin.
It is known in physiology that respiration rate is more or less determined by concentration of CO2 in the blood. Probably doesn't need to be independently tested.
You’d still want to test. And if it was increased, the next thing to test would be whether a 10% increase in baseline respiratory rate was benign. It’s not obvious that it would be, since breath is so tightly regulated.
OP spoke with rather more certainty than warranted.
> At 5 millibars (5,000 ppm), you would start breathing at a 10% elevated rate, which you probably wouldn’t notice.
Wouldn't you? Won't you subconsciously notice and want to end the meeting faster?
Imagine breathing at an elevated rate in a crowded room that lacks proper ventilation. There's more than co2 coming from the human body. People will begin sweating, farting, etc., and fill the air with all kinds of pollutants. The computers, screens, dry erase board, etc. will make the situation even worst.
I know that such a room will make me want to make quick decisions to leave quickly.
>Imagine breathing at an elevated rate in a crowded room that lacks proper ventilation. There's more than co2 coming from the human body. People will begin sweating, farting, etc., and fill the air with all kinds of pollutants. The computers, screens, dry erase board, etc. will make the situation even worst.
Your description makes me think of the opening scene from Falling Down.[0]
You're referring to a psychological effect, he's referring to an autonomic. It's the same way the you don't tend to notice your heart rate increase and decrease as you move around unless it's major.
The opening post was about a psychological effect to which this poster responded "No. I wrote up the computations explaining why." and linked to a paper which had as a conclusion an increase in breathing rates.
My point is that a crowded room likely has more than one causes which could explain why productivity is lowered and decisions making worsened.
You won't notice an autonomic response but your brain likely will and it might very well answer by releasing adrenaline, cortisol, etc., and make you more anxious and stressed to encourage you to leave the environment that is causing the increased breathing rates.
Back in college, I worked on a project whose goals were to examine the effects of closed room vs. fresh air cognition. The solution was a partnership between the Architecture and Biotech departments to develop so-called "living walls" to continuously recycle air. In accordance with this article, test subjects showed improved cognition and memory working in fresh, low co2 ppm air.
The objective was to find an eco-friendly method to do so. Thus the living walls, and not just outdoor air intake (which would cost power to run the fans, similar to the energy footprint of running an AC). I can't comment on average outdoor air, but plants certainly helped.
Sorry.. I meant do expirements measuring cognitive performance relative to co2, find an optimal level, and if so is that level what you'd typically get outdoors?
Were the visual and odor aspects hidden from the participants? If you put some monkeys in a blank white room to do some tasks and some others in a room with visible Flora and the smell of Earth and plants, I suspect the lattre group would perfo better even with O2 an CO2 levels constant.
Plus the comment 4 levels up had "C02" rather than "CO2".
<rant>
I searched for why people do this 1337-substitution [1], and apparently the justification's that "C02" can be quicker to type on some mobile keyboards since "0" is a single press while "O" requires hitting Shift too.
But in chemistry, we'd often write chemical formulae in linear format. For example, "H2O" is water while "C6H12O6" refers to some simple sugars. The basic rule is that digits after any letters are in a subscript position, while digits before any letters are a scalar multiplicand.
So, when I see "C02", I immediately parse it to "{C}_{02}" rather than "{C0}_{2}". This reduces to "{C}_{2}", which obviously doesn't make sense, so then I have to figure out what's going on. Obviously it's not too tough to figure out from context that "CO2" was meant, but since I have to infer that from context rather than from direct parsing, it comes off as an obnoxious typo. For example, if someone wrote "C2O", I could figure out what they meant from context too, but it's still annoying to have to be like, "What?".
Then I don't even know why it exists. I mean, who talks about CO2 so much more than other chemical species to memorize a 1337-alteration that saves them having to hit a Shift key? It seems like a rather niche micro-optimization that certainly can't be worthwhile to too many typists, even if we ignore the obnoxiousness it imposes on readers.
Which, tl;dr, my point's just that "C02" might be a cute 1337 substitution if you don't usually read a lot of chemical formulae, but if you do, it invokes a parsing error that you either have to consciously resolve or else memorize a new slang term to avoid.
It wasn't a deliberate substitution, just a result of typing quickly, having 'O' next to '0', and having them be hard to distinguish with the font I was using.
When I was a student I had a little room and one time I had a co2 monitor in my room for a few days. The monitor had 3 leds, green yellow and red. While sitting in the room for three consecutive hours (at the computer) the co2 would slowly rise from green to red and after opening the window for a while it was back at green. Now the interesting part is that I felt a strong correlation between tiredness and high co2 levels (I was surprised how strong this effect was) and that opening the window really did help. Since then I thought that every classroom needs such a device.
Would definitely be an interesting longitudinal study to put a sensor in a set of classrooms, some of them with a your light system to suggest opening a window, and some of them not being told about the sensor, which would just log data as a control. You could compare grades and long term success in people in those classes.
Even in the short term it would be interesting to see if it affects any education metrics.
I now am very conscious about keeping a door open and getting some fresh air into the room. This is a challenge in modern, well-insulated buildings in Florida in the summer.
> Yesterday I carried my CO2 monitor around to various meetings in different places (much to the amusement of those with whom I was meeting). Every place I checked was at least 200 ppm higher than outside. In one office, two guys are working in a room that read over 1,500 ppm. I wonder if they would be more productive with proper ventilation.
That's worrying. Did you let them know? What was their reaction?
They are usually triggered by a timer or humidity, but it would be also possible to trigger them based on VOC or CO2 levels.
Single-room heat recovery ventilation units are relatively affordable (about $400). There are also some which can be integrated into the window frame if drilling a 6" hole into a wall isn't an option.
I have read about such systems. I have not seen any in Florida. Do they work for keeping heat out while exchanging air? Where I live, we are trying to get rid of heat, not recover it.
If human breath is in the 3.5-4% range, how does the difference between .05%(green building), and .15%(conventional building) in ambient air make such a large difference? It sounds like the small sample size exasperated the issues. The results are much less conclusive looking at other studies.
I can't speak to the study. My empirical results carrying a CO2 monitor around for just under one year show me that well-insulated buildings have much higher CO2 than drafty buildings. This is in Florida, where we generally keep doors and windows closed so as to not waste the energy we spend on air conditioning.
Boston winters sometimes make cracking open windows impractical, but if you're in a typical old multi-unit building with old steam/water centrally-controlled heating, there's a good chance that your unit is too warm anyway (though some other units might be too cold). I've heard that some of these old heating systems were even designed assuming cracked-open windows.
The main downsides I'm aware of to open windows here usually are outside noise and seasonal pollen. For the pollen, you can run an air filter and HEPA vacuum robot and/or (supposedly) install special window screen material for the pollen. If you're in a very noisy area, that sometimes means opening and closing window based on noise at the time. If outside noise at night or early morning can be bad where you are, that might mean frontloading bedroom fresh air in the evening before bed, but shutting window before bed.
I don't know about air pollution from fossil fuels, industrial, etc.
For anyone considering this in a winter area: you only need a window open a crack to ventilate a whole apartment. More circulation happens due to the heat differential (I think?)
In any case it has little effect on heating bills. My canadian grandma actually used to have a window cracked open all winter, and she was rather frugal. My own heating bills changed little since I started.
There must be some shape that can work as both air filter and heat exchange, so one could have ample air circulation while keeping the heat inside, at the cost of having to wash it once every few months.
I have been looking into some whole home humidifiers myself, because it gets so dry in the winter where I am at. Not sure they are an option for you, but they hook right into the HVAC. That way ventilation would help rather than hurt.
There are heat-exchanging air exchangers for high-efficiency construction. I'm not aware of (and don't find) humidity exchanges, though they may exist.
Hung dampened linens (towels, bedsheets) can make a big difference. Many HVAC systems offer high-efficiency humidifiers, and the old standbye of having a kettle on the stove can work (with an energy cost).
Humidity in general is fairly cheaply acquired. Dehumidifying moist air takes much more energy.
Get your kid used to drinking more water. I used to get nosebleeds all the time in winter as a kid and teenager, but I've since been a very avid water drinker and my rate of nosebleeds has gone down considerably.
There are energy recovery wheels, which take advantage of some sort of adsorbent to transfer humidity from the outbound to inbound stream and recover some of it (or the reverse, keep indoor air conditioned)
I remember in high school, there were certain classes in which I always got really tired. Eventually I realized they were the classes with the most students stuffed in the smallest rooms. The worst offender, for example, was health class (ironic in hindsight, I suppose), which took the place of phys. ed. for one quarter and therefore had to fit an entire gym worth of students into a single classroom.
I've worked in modern steel and glass buildings in the Valley, and I've also worked in old (and drafty) converted warehouses in SF. I never really thought about it, but I definitely get more tired in the steel and glass buildings (which usually have inoperable windows).
I work at home now, and while my home is well sealed, I always try to crack the window in my office to let in some fresh air. I'll have to make an effort to do that even when the weather isn't as nice.
Interesting links, thanks! So it's mostly an IR lamp, an IR sensor with an optical filter and the air to test in between. I don't understand from the article how long the waveguide actually is. Is this just a cylinder that is a few mm long bent around a corner, or is this some hollow tube much longer wound around the center of the sensor many times?
> Can you make them small and cheap enough to put in a phone, so I'd get a notification if the CO2 levels are rising?
Yes! It's possible. But the air circulation inside a smartphone is limited and newer phones are completely sealed for waterproofing, so there are still some doubts.
> How are CO2 sensors built?
Based on my very limited experience on playing with electronics, I would say...
1. Previously, many CO2 sensors use an electrochemical process, the chemical cell in the sensor reacts with air, and outputs an analog voltage proportional to the gas concentration. They are large, have a distinct cylindrical shape similar to a microphone module, needs manual calibration, and common in the industry. For example, have a look at the datasheet of MG811 sensor, which mentioned how the chemistry works: https://sandboxelectronics.com/files/SEN-000007/MG811.pdf
2. NDIR sensors is another traditional option. Inside a large rectangular blackbox, it has an infrared LED and some electronics. Basically, you shoot a beam of infrared light though the air and detect it on the other end, and correlate your measurement with the gas concentration. NDIR is reasonably accuracy, very popular in the industry, and can detect particulate air pollutants, and many types of gas. As an example, take a look at the MH-Z16 datasheet: https://sandboxelectronics.com/wp-content/uploads/2018/08/Z1...
3. It's now possible to build an all-in-one digital gas sensor on a piece of semiconductor chip! Examples include:
Curious where you are getting those figures from. Looking at the usual suspects (newark, digikey, sparkfun etc...) gives figures like $5-20 a piece (even at bulk).
Ive run into this before with some hobbyist electronics (high fov IR LEDs) where the prices were much higher than one would expect.
> Curious where you are getting those figures from. Looking at the usual suspects (newark, digikey, sparkfun etc...) gives figures like $5-20 a piece (even at bulk).
edit: I meant to say the cost is 5.76 USD each per 1000 pieces, I should've been clear. In the industry, it's common to quote the price as "1k price", which is the 1 pcs price per a bunch of 1000 pcs.
> I've run into this before with some hobbyist electronics (high fov IR LEDs) where the prices were much higher than one would expect.
Hobbyist electronics are more expensive than the raw price, sometimes an order of magnitude, mainly because they're not mass-produced. If the part is expensive, this effect is there. But usually the cheaper the part, the stronger the effect.
In electronics mass-production, when you already have a PCB and you add a new chip, the cost is often close to the chip itself.
On the other hand, a breakout board or a devboard usually only has few chips on the board, sometimes nothing more than the soldered chip, with a voltage regulator and some pull-up resistors for "plug-and-play" experiments. Also, they are produced in small quantity so the cost cannot be low, and finally vendors like Sparkfun usually sell them to the hobbyists at a premium. For hobbyists, the point is to have something ready to work with, plus it's increasing impractical to solder some chips by yourself due to the increasingly small footprints, and anyway, even if you are gonna run a production, you need to see how it works first. So these hobbyists electronics are more expensive compared to the cost in the industry.
I just want to plug a client that I worked for that solves this problem: Healthy Workers.
Healthy Workers is a Amsterdam-based startup that measures thing such as: air quality, CO2 and consented employee data (e.g. their sleep and focus) and makes an analysis what parts of the building have an unconductive work environment and how this can be improved.
Conference rooms with bad air are the first problem they look at.
That's such an overlooked problem. Companies with healthy finances might have all the comforts like great chairs, tables and IT equipment but the rooms might just be overheated and have bad air. Would be great if this would be added to the list of ergonomics.
In fact this is probably one of the undisputed pros of an open office, the air quality is most of the times quite good.
Google has tracked office air quality for years, e.g. through the Aclima partnership.
That's basically because Larry Page really, really cares about it. He's kinda like your friend with a Kubrick obsession that can't stop bringing up facts:
He was on to something! Jokes aside, I think he just has a heightened sense of smell and that's why he had air filters stronger than law requirements installed everywhere, at least in Mountain View.
> I think he just has a heightened sense of smell and that's why he had air filters stronger than law requirements installed everywhere
Quite possible. I have a very strong sense of smell ever since I started hormone replacement therapy and it's driving me crazy how people can put up with some bad smells.
- I can pinpoint mold with a surprising accuracy -- it's everywhere, you'd be scared.
- I can tell when a bathroom is not properly ventilated -- had the office test it out and they changed the entire air ventilation system of that part of the building because it was not up to code.
- I could even smell if the driver in front of me is smoking in their windows closed car while I'm driving behind it with my own windows closed -- changed my air filters.
I'm absolutely certain that a lot of buildings are lacking in air quality and if I were the owner of any industrial or commercial building I'd make sure to invest in top quality air filter.
Hmm. I tend to always have my window open, no matter what the season (If its winter I will just wear some jumpers)
I can't abide stuffy rooms with no window open.
I also like to think and read and create and use my brain a lot.
I wonder if subconsciously I have been seeking out enough oxygen.
I once went on a very low carb diet, apparently the brain needs to burn glucose. Mentally I did feel dumb / dull / numb after a while on it. Perhaps the same way I'd feel in a stuffy room for an extended period of time.
ps. This is just more damning evidence to add to the case against working in an office as opposed to remotely.
People on this thread mention co2 monitors can't be so cheap, but I'm under the impression this is actually measuring co2 and not o2/vocs. Can anyone confirm?
You're likely living there as your economic circumstances compel it. I would say that if the sensor shows a high co2 number, you should carefully consider all options you have in your life and see if there is any way out of this situation.
If the studies are correct about high co2's effect on cognition, sleep etc then this home environment is likely contributing to keeping you in whatever situation you struggle to escape from.
(If $90 is too much, you can perhaps borrow one from someone local)
Have you tried running one of those near major road intersections, with lots of cars idling?
I spend all day in the office with windows looking on a parking lot with two intersections nearby. Considering how much it always stinks of car exhaust right outside, I have a strong suspicion that ventilation that everyone so praises here might not be all that beneficial. But $100+ for CO2 detector is too expensive for where I live.
There are tons of papers on this subject (thanks Sci-Hub!), but the results they report vary so much that it is difficult to draw any conclusions.
An idling truck on my street will fairly quickly raise my indoor co2 levels unless I shut the window. You also get particulate pollution.
My guess is you’re right, and in your local area ventilation may not help. Though it depends on distance from the road. Dissipation happens fairly quickly with distance iirc.
Haven’t been able to test at a freeway, mm co2 meter requires an electric outlet.
In my area make up air is required in commercial spaces, but it’s uncommon in residential unless there is a giant kitchen with 1000+ cfm range hood. Air circulation is running all day in most buildings I’ve worked in.
His wife was literally being poisoned by the off-gassing in their new home. A relatively inexpensive air quality detector (Awair) now helps them keep tabs on things.
I've got an Awair in my office, and love it. When CO2 gets too high, I step out and work from my porch.
For those asking about house plants, the answer in my experience is that they don't make a difference. You have to have a lot of plants to offset the CO2 that you produce.
I would have assumed Gwern would have come through and shared his results already. If you're interested/scared about this, you could do worse than replicating https://www.gwern.net/zeo/CO2
Would love to see what the numbers are for a rush hour subway car in NYC. Can imagine it's a great way to juice your brain before the start of a workday.
Any idea what typical gym numbers are? I would have guessed they aren't as bad as office buildings, as they are large spaces and generally have ventilation systems. I'll bring my co2 monitor when I try the new gym in my neighbourhood though.
My guess is that the benefits of the 30-60 minutes 3-6x a week you spend in the gym far outweigh any of the negatives of elevated CO2 exposure. You know when a gym has poor ventilation which means that's not a gym you want to be at.
That price seems about right. Many "CO2" sensors are actually measuring VOC levels then extrapolating what the CO2 level probably is rather than measuring it directly. You can see in the specs that this sensor uses NDIR (Non Dispersive Infrared ) to measure the CO2. NDIR fires an infrared laser at a specific frequency of light which falls into the absorption spectrum of the C-O bond of CO2, this scatters the light; This dispersion is measured and then turned into a PPM measurement of CO2. This sensor says it uses this NDIR technique and so is probably measuring the CO2 directly.
Every property management company will set the recycled percentage in the HVAC system to a different amount based on climate and budget. In my opinion, folks should bring a Co2 sensor to work and then ask their facilities team to work with property management to lower the recycled air percentage if the ppm is too high.
You can expect them to push back and cite OSHA guidelines [1]
Wonder what the effects would be like in a coworking space/open office environment? Would the levels of CO2 be higher in the likes of a WeWork than a typical office setup? I remember coming across one similar setup where about 30 startups were working from a basement with pretty much no windows.
Then again, wonder what it'd be like in the average subway train or something. Even with decent ventilation systems it feels like the issue would be worse in a packed train/station during rush hour, though the effects would be limited due to no one actually doing any work there.
The US Navy's submarines are run with CO2 levels varying from 300-11,300ppm.[1] The military did plenty of studies in the 60s and 70s and failed to find significant cognitive effects in environments as high as 4% CO2.[2]
> Thus, CO2 at 40,000 ppm for 2 weeks did not affect performance on multiple tests of cognitive function in physically fit young airmen, a population probably not unlike submariners.
> A number of studies suggest that CO2 exposures in the range of 15,000-40,000 ppm do not impair neurobehavioral performance. Schaefer (1961) reported that 23 crewmen exposed to CO2 at 15,000 ppm for 42 days in a submarine showed no psychomotor testing effects but showed moderate increases in anxiety, apathy, uncooperativeness, desire to leave, and sexual desire.
> In a 5-day exposure of seven subjects at a CO2 concentration of 30,000 ppm, Glatte et al. (1967) reported no effects on hand steadiness, vigilance, auditory monitoring, memory, or arithmetic and problem solving performance.
> CO2 exposure did not affect performance on the tracking task or any of the six RPM subtests (Storm and Giannetta 1974).
There's also an argument from biology. When sitting around, people exhale 4-5% CO2. That's 40,000-50,000ppm. An extra 2,000ppm is far less than the variance across a typical breath, and it won't increase ppCO2 in the blood stream nearly as much as standing up and walking around. If CO2 hurt cognition as badly as these studies claim, then even minor physical exertion should turn people into drooling idiots.
It's for these reasons that I am extremely skeptical of the recent claims about CO2 impairing cognition.
If it's not CO2 the real cause might be even more interesting, if a real negative effect does exist (which it seems to do, given the recent studies). I find it interesting that
1) they disagree based on the tests/methodology used
2) no one seems to be acknowledging the military research from back then (which I have to say, I didn't know about myself).
Re 2: Military research gets ignored all the time despite (because?) it often outpacing academia by decades. Not sure exactly why this happens, just wanted to note this phenomenon isn't specific to CO2 levels and cognition.
Maybe, Military has strong incentive to conclude that CO2 level not affecting the soldier's intellectual and physical activities so they don't need to spend extra cost for submarine to keep the CO2 level low.
The Military has very little cost constraints. If they can show that CO2 impacts negatively the performance of troops they will get funding as needed. They are not run like corporations at all.
I think the military has a strong incentive to not have submarine crews with impaired intellectual and physical activities so they can perform as designed.
Yes. The question of CO2 and the difficulty reconciling Satish with practically all other CO2 studies has been a question of interest to ggreer & me since it was first raised on LW years ago: http://lesswrong.com/r/discussion/lw/nk0/what_is_up_with_car...
Was just reading that through and idly wondering, if that was the only experiment getting such a result, and there is nothing obviously wrong with the methodology, was there anything else by accident in the tank or gas lines they used for the CO2?
Not the first explanation I would reach for. (What would have to be in those tanks? Nitrogen would be very noticeable and wouldn't do anything, oxygen would presumably help rather than harm, and so on.)
It isn't submarine crew sitting in those conference rooms.
Not to mention the dreaded so-called "open-spaces". The tasks are completely different and no one gets half a year time off the tub. So the studies you cited are irrelevant.
In fact, inadeqate air quality was one of the three main reasons (two other being interruptions and commute time) that drove me to exclusively remote work 10 years ago. It took a lab-grade CO2 detector and some references to half-century old health standards to make the first step, but it worked.
2 hours in a meeting room is just plain exhausting, I'm 100% certain than I am more willing to compromise or walk out with shitty decisions by the end of it.
What if people are just dumber in crowds? I can imagine that as a psychological effect of heightened social awareness/interaction. Part of our cognitive capacity goes to that.
Thank you for linking some studies! This is very interesting to me, since I have noticed CO2 levels having a major effect on my work routine.
There is a CO2 sensor on my desk for 10 years already. Generally it is around 650 ppm during a working day but occasionally the building's ventilation system's power trips and air movement suddenly decreases. This causes CO2 levels to rise fast - once they hit 900-1000 ppm, I can definitely feel a decrease in my ability to focus and think clearly (and yes, I feel it even before looking at the numbers, ha!).
Obviously silly single anecdote but subjectively the link is very strong for me!
PS. On a sad note is that I remember the days when coming to work in the morning meant the CO2 level was at 350 ppm. These days clean air is 450 ppm in this city!
Maybe I'm missing it but it seems like most of the studies I click on there see an effect at CO2 levels that are much less than tens of thousands ppm.
Gwern has this to say about the Navy studies-
"they often were not using sensitive tests of higher cognitive functioning, a broad array of different measurements, and very small sample sizes; I suspect a meta-analysis grouping tasks by domain with some correction for ceiling effects might turn in a very different conclusion than their fairly sanguine conclusion that there are no cognitive impairments <40000PPM and <25000PPM is a perfectly safe limit. (Oddly enough, I came across this book on an anti-global-warming site; apparently Satish et al 2012 is really just global warming propaganda scare tactics, because the Navy has proven that CO2 is perfectly safe.)"
I mean the Navy has a very vested interest in saying "submarine CO2 levels are fine" which makes me suspicious from the outset. If other studies corroborated their claims I'd find it more believable.
If what you say is true then there is an almost unprecedented level of being wrong and conspiracy in the current accepted rules and limits for CO2 in indoor air quality. Not to mention the fact that Wikipedia is dead wrong. That seems unlikely.
"The National Institute for Occupational Safety and Health (NIOSH) considers that indoor air concentrations of carbon dioxide that exceed 1,000 ppm are a marker suggesting inadequate ventilation."
It would be quite bizarre for NIOSH, a division of the CDC to be 15-40x off on how much CO2 is acceptable indoors. I'm assuming like most government regulatory bodies they looked at many studies and formed a consensus about what is safe using the available literature.
There's a big difference between seeing high concentrations of carbon dioxide as indicative of poor ventilation and seeing high concentrations of carbon dioxide itself as detrimental to cognitive function.
1. It is not enough to win. Someone else must lose.
2. Learn the distinct odor of fear. Pinpoint the source.
3. Ask everyone to pull their own fingers before the meeting begins.
4. If you have a video whiteboard, train the camera on it with a bit of zoom and give your presentation in front of it so your moving form is surrounded by a throbbing infinity of fractal shapes.
5. Place a slow incrementing digital up-counter on the table and say it's a CO2 sensor.
Attributed this to the richer environment of nature, but it turns out that there is scientific research that finds a correlation between cognitive ability and airflow: https://www.sciencedirect.com/science/article/pii/S036013231...
Short answer: yes.
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