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I really wish a Apple or another major OEM would integrate CO2 monitor into watches or smartphones. Suddenly, everybody would be aware of the CO2 level in the r

• scoot 3mo ago
  Apple watches already have a blood-oxygen sensor so it's covered, albeit indirectly.
  • oasisbob 3mo ago
    I don't think that's true at all. Capnography, the measure of carbon dioxide partial pressure is wholly separate from pulseox: > Pulse oximeters have some limitations. They can only employ light at two wavelengths. Thus the devices can only distinguish between hemoglobin and oxygenated hemoglobin. When carboxyhemoglobin and methemoglobin are also present, there are two additional wavelengths required for differentiation. In the presence of elevated carboxyhemoglobin levels, pulse oximetry overestimates the true saturation of oxygen as carboxyhemoglobin binds with a higher affinity than oxygen. In the case of carbon monoxide poisoning, the absorbance spectrum of carbon monoxide is very similar to hemoglobin, which results in a falsely high level of oxygen (overestimation of oxygen saturation) ... https://www.ncbi.nlm.nih.gov/books/NBK539754/ https://www.ncbi.nlm.nih.gov/books/NBK539754/
    • benj111 3mo ago
      >Pulse oximeters have some limitations. They can only employ light at two wavelengths Why only 2?
      • oasisbob 3mo ago
        I think that might be a descriptive statement based on what's in the market, vs hypothetical implementations.
  • Terr_ 3mo ago
    I don't think that's safe to assume at all, for two reasons: 1. CO2 has effects on the human body of its own that aren't simply a lack of oxygen, and vice-versa. [0] 2. The baseline proportions involved aren't close, so even doubling CO2 isn't going to show up easily as a large swing in in oxygen%. For example, the article references a study where the CO2 proportion going from 0.04% -to 0.25% correlates to mental problems. Even if the watch could sample atmosphere directly, is it sensitive enough to detect a shift from 21.00% -> 20.79% oxygen? As it's estimating oxygen in the owner's blood, it might not detect anything different at all... not if the owner's body has already compensated by breathing harder or by "underclocking" their brain to make dumber decisions. [0] https://en.wikipedia.org/wiki/Asphyxiant_gas https://en.wikipedia.org/wiki/Asphyxiant_gas
    • ErroneousBosh 3mo ago
      > The article references a study where the CO2 proportion going from 0.04% -to 0.25% causes mental problems. In other words, a difference in 0.21% of the air. I'm finding that pretty difficult to believe, to be quite honest with you. And before you say "aha, carbon dioxide brain fog!" consider that I'm about a mile from the sea with a 40mph onshore breeze. This air is about as oxygenated as it gets.
      • Terr_ 3mo ago
        1% (10,000 ppm) is enough for the person to become aware something is odd through drowsiness or an elevated heart rate. I don't think it's too far-fetched for a quarter of that to cause subconscious cognitive effects, that could be measured in tests.
        • ErroneousBosh 3mo ago
          The air in your lungs sits around 40,000ppm or 4% carbon dioxide. In every breath you remove about 25% of the oxygen from the air in your lungs, which is why mouth-to-mouth resuscitation works, at all. Most of the oxygen is still in there. To be clear, that 25% represents a change in oxygen level from around 21% to around 16%, so the few tenths of a percent change in carbon dioxide just isn't a huge amount.
  • scoot 3mo ago
    I really must learn to quote the full context of a reply. OP said: > just due to lower oxygen levels in your blood So my comment is in response to that. PS. The downvote button isn't a disagree button. (Although how you can disagree with the fact that Apple watches have a blood oxygen sensor I don't know).
• legulere 3mo ago
  I guess the problem is with the price of the sensors. Just look how expensive the Aranet 4 home shown in article is. There are worse devices for less like the IKEA alpstuga. I also don’t know how much electricity they pull.
  • Gigachad 3mo ago
    I got the ikea sensor, I’d say it’s way more accurate than you need for personal use. I wouldn’t use it as a scientific instrument but it’s well good enough to see if the room is ventilated enough. I was shocked to see just how fast CO2 climbs while in a room, and how just opening the window just a crack was enough to restore the room to baseline co2. The thing runs on usb 5v so the power consumption is negligible. It also plugs in to home assistant great.
    • p-e-w 3mo ago
      > The thing runs on usb 5v so the power consumption is negligible. There’s a huge leap from that to the power consumption being low enough to be integrated into a smartphone, as demanded by OP.
      • progval 3mo ago
        I don't think power use is the issue. I have this cheap CO2 sensor: https://www.domadoo.fr/en/devices/5882-heiman-zigbee-air-quality-sensor-co2-temperature-humidity.html https://www.domadoo.fr/en/devices/5882-heiman-zigbee-air-qua... which draws 0.5W. This includes thermometer and humidity sensor, Zigbee transmission, and acting as a Zigbee router, but it gives us an upper bound. It also measures continuously (picks up someone breathing on it within 10s), which is overkill. A phone could measure CO2 levels once every 10 minutes which would average under 0.01W, so that would work. However, this assumes the sensor would fit in a smartphone, which is not a given. And these things need air flow. And they also wouldn't work while the phone is in a bag or a pocket.
        • nnevod 3mo ago
• aaron695 3mo ago
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• stein1946 3mo ago
  > Raising awareness is the only real solution. You'd have to raise awareness on every single person in the room and them sustain pressure to the organization in order to have proper CO2 levels in the room/organization. And then you have to align every other person on every other organization to do this as well and hope for the best. Or, you can do the right thing and have the state introduce regulations
  • b112 3mo ago
    I can just imagine the horrors and skin crawls that your last sentence has evoked in some people's minds. Not the state!! But seriously, so much care needs to be taken here. OK, well "care" at least. Employers certainly would benefit from scrubbing CO2 from the air, in terms of productivity. I'm willing to bet that with central air it would be quite easy, and even with heat and AC off, lots of places still circulate the air regardless. So the central place to scrub is already there. But then you have other issues. Such as, will your body adapt to 8 hrs of reduced CO2, and then you become torpid and barely awake when not at work. Such a horrid thought, that is to me. And what if employers learn that the tiniest boost of O2 helps too! Now your body becomes accustomed to that, and what are the long term effects there? I can personally envision myself being concerned. I guess the legislation could be crafted to "the same CO2 levels found just outside of downtown city core" or some such blather. Maybe even same for O2. So that you're at least pegged to something normal for the area. Maybe that's where the state could come into play. A simple, highly accurate monitoring station which has an API to be polled. Come to think of it, CO2 and O2 rates fluctuate during the 24 hour cycle. Trees need O2 to live, but only produce O2 during the day. And so differing amounts of light might mean up and downs in these numbers. It may be another circadian rhythm. Getting it the same as in a nearby forest, might be the healthiest thing of all.
    • atoav 3mo ago
      It is not that complicated. You need to introduce CO₂ threshold levels that make sense from a medical standpoint. Then you need to enforce them in the same way other basic environmental regulations or worker rights are enforced in regions of the world where these work. The main question is: If your workplace, city, whatever forces you to work or live in an harmful/unhealthy environment, do you have any realistic course of action to improve the situation? In the US you would call this (gasp) regulation, I would call it a basic human right. If we talk about stairways, nobody complains about building regulations that mandate handrails. CO₂ levels are not totally different.
• zeafoamrun 3mo ago
  I was looking at CO2 sensor module boards this week and the sensors themselves are quite large and the floor price is $15ish.
  • bjackman 3mo ago
    And I believe the accuracy is also not great on these cheap ones. The product in the OP's photo costs $200 where I live! And ISTR finding the sensor itself contributes a lot to this cost. IIUC they also need fans. The one I have in my home has one that's actually integrated into the sensor unit.
  • Gigachad 3mo ago
    Those $15 ones are also straight up scams. They just estimate (lie) for the readings based on other sensors.
• microtonal 3mo ago
  I think the issue is that the common tech requires sensors in an air-chamber. E.g. NDIR works by firing IR at a frequency that is absorbed by CO2. A sensor on the other side either measures the amount of IR light that got through (optical NDIR) or pressure/sound waves (photoacoustic NDIR). I guess that it's hard to use any existing sensors, because they are relatively large and probably water could easily get into the chamber. Would be extremely cool if Apple, Samsung, and others can crack this, though I think they'd have done it already if it was easy.
  • londons_explore 3mo ago
    Oxygen sensors used in car catalyst systems use a different effect based on electrochemistry. I see no reason that couldn't be minuaritized to grain-of-sand size. The question is if oxygen levels are as good an indicator as CO2 levels... I suspect not.
    • noja 3mo ago
      I don’t think we actually care about co2 levels. I think we use them as a proxy for o2 levels (same as our bodies do). So your idea would be great.
      • noosphr 3mo ago
        We do.
      • dgellow 3mo ago
        What makes you think that?
      • XorNot 3mo ago
        This is extremely wrong: CO2 impairment kicks in around 1000 ppm[1] possibly lower. You can hit this breathing by yourself in an unventilated 3x3m room (literally measured in my house). 1 https://pmc.ncbi.nlm.nih.gov/articles/PMC4892924/ https://pmc.ncbi.nlm.nih.gov/articles/PMC4892924/
• reddozen 3mo ago
  CO2 and all other air quality indexers have to be very carefully calibrated regularly. It's not some slop you can just throw into a consoomer cheap iot device. Article author completely ignores this for the obvious reasons.
  • Gigachad 3mo ago
    For the purposes of indoor ventilation monitoring you can calibrate by occasionally exposing the sensor to fresh air. Either taking it outside or just the room not having people in it. The sensor will treat the lowest reading it gets as 400ppm since this is what outdoor air is. A sensor mounted in the office will get calibrated every night when the office is empty.
    • OutOfHere 3mo ago
      The outdoor CO2 is rising every year. It is not fixed at 400 ppm. The calibrations you speak of are fake. A good sensor can be expected to remain within 10% of reference for ten years.
      • mikestew 3mo ago
        The outdoor CO2 is rising every year. It is not fixed at 400 ppm. But close enough for most purposes. We aren’t doing laboratory measurements here, I just want to know whether or not to open a window.
        • OutOfHere 3mo ago
          You don't need to routinely calibrate a good device at all for that purpose. It already will maintain a reading within 10% of the real value. If it's not doing that, it's a bad device. It's very possible your calibration process will actually miscalibrate it and increase the error. Already the outdoor CO2 level is 430, not 400, so you'd be introducing at least a 7% error by calibrating it to 400. What I do at home is I have multiple meters bought over the years, not all at once. If one of them is too deviated, I can replace it, but this deviation has never happened in the last five years. It did happen once about ten years ago with an old model.
• throw0101a 3mo ago
  > There are so many rooms, classrooms, movie theaters and other places with poor ventilation where you just feel dizzy, or fall asleep, not knowing it was just due to lower oxygen levels in your blood. Raising awareness is the only real solution. Not wrong, but it is perhaps worth noting that there are already standards for proper ventilation. Generally you're looking at 5–10 cfm/person (2.5-5 L/s), depending on the facility and purpose of the room; see Table 6.2.2.1 in ASHRAE Standard 62.1 for the US: * https://www.ashrae.org/file%20library/technical%20resources/standards%20and%20guidelines/standards%20addenda/62_1_2013_p_20150707.pdf https://www.ashrae.org/file%20library/technical%20resources/... Maybe set up a monitor, but if the room/facility has recently been renovated and meets modern (>2013) building codes, this 'should' have already been taken into account.
  • wouldbecouldbe 3mo ago
    I think modern domestic houses its the opposite. At least in Netherlands insulation is such a strong focus, due to climate change I think, that modern appartments have terrible ventilation
    • avhception 3mo ago
      A friend of mine recently moved to a modern apartment, built only a few years ago to a very high isolation standard (Germany). I stayed over night and slept on his couch, the air got really really dry and stuffy. It was really uncomfortable.
    • hydevito 3mo ago
      Stayed at a beautiful new house in Finland, with five people instead of the usual two, the CO2 detector intermittently went off while we were sleeping. Which the hosts assured us was a faulty detector. They also spoke to how extremely energy efficient the house was, to us it seemed like there wasn't enough ventilation, to improve the insulation. Against their wishes, I slept with all windows fully cracked, which was only ~2 inches due to the "efficient" design.
      • 3mo ago
• bhouston 3mo ago
  There is one in the EcoBee Premium and we use it to automatically drive our HRV (heat recovery ventilation.). It is better to have it in the HVAC system than in your phone anyhow: https://ben3d.ca/blog/upgrading-hvac-control https://ben3d.ca/blog/upgrading-hvac-control
• alienbaby 3mo ago
  Is it a tually lower oxygen in the blood that's the problem, or higher co2? I'm not sure if having high co2 automatically implies lower oxygen, I have no idea at all but feels like it may not necessarily be strictly. Linked. Also, are the cognitive issues of low oxygen the same as high co2 or do they produce different effects?
  • fhdkweig 3mo ago
    From what I learned from Apollo 13, even with O2 in the air, CO2 can still be poisonous.
• jeffybefffy519 3mo ago
  This would probably be the biggest awareness thing tech could do for climate change as well.
• 256dpi 3mo ago
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• misnome 3mo ago
  I built a conference badge with a proper, laser-based CO2 sensor. It didn't work very well because just by virtue of being near me all the time, it didn't get a very good measure of the average room contents.
• Aurornis 3mo ago
  > I really wish a Apple or another major OEM would integrate CO2 monitor into watches or smartphones CO2 levels are locally elevated in the area where you exhale. Someone sitting at a desk with their hands on a keyboard exhaling through their nose would be producing a directed stream of elevated CO2 straight at the sensor on their wrist. Same thing if someone puts their phone on their desk. Even with the IKEA and other cheap sensors that are becoming popular, there is a learning curve where users discover that putting it on their desk right in front of where they’re breathing produces higher numbers than having it even 5 feet away. The false positives from having a CO2 sensor that close to everyone’s face would be causing unnecessary alarm all over. > There are so many rooms, classrooms, movie theaters and other places with poor ventilation where you just feel dizzy, or fall asleep, not knowing it was just due to lower oxygen levels in your blood. Raising awareness is the only real solution. If someone is falling asleep in this many different places I would suspect undiagnosed sleep apnea or another condition first and foremost. Spaces like movie theaters have very high volumes of air due to their size and commercial building HVAC has much higher standards for air circulation than even your home. If someone was falling asleep in so many different places then the most likely common theme is that person and it should be checked out! This is another reason why putting CO2 sensors on everyone’s wrists would be a mistake: It would start getting blamed for every vague condition people experience. This has already happened with wrist-worn heart rate monitors. My friends in the medical field see people all the time who come in with vague complaints and they’ve self diagnosed as being related to their heart because they can see their heart rate now. You also have the wrong idea about what elevated CO2 does. It doesn’t reduce the oxygen levels in your blood. It makes it more difficult for your body to expel CO2, which can produce subtle changes in many processes.
  • riquito 3mo ago
    > CO2 levels are locally elevated in the area where you exhale. That's the same area we inhale from... Wouldn't be right to measure there then? It's not like we're interested in the amount of CO2 on the ground (in this discussion)
    • Aurornis 3mo ago
      No, because the studies that establish the levels correlated with cognitive changes use ambient CO2 levels. Not with a stream of air directed, maybe, from your nose to your wrist. It is not possible to come up with a different baseline for wrist-worn monitors because the measurements could change significantly based on even small factors like the position of the wrist or smartphone.
• pedalpete 3mo ago
  I always come at this angle. If you had the data, what would you do to change it? Would you recommend everyone go outside? You can do that without the data. Would you wear your own oxygenated supply of air? You can do that without the data. Would you make recommendations that the office should improve air quality? You can do that without personalized real-time data. I'm not against data in general, but the idea that if only we had data we would make changes in our lifestyle is not valid. We see it all around us. We had bathroom scales for over a century, but the data or insights didn't put a dent in the obesity epidemic. You're right about "the problem will solve itself", but it isn't the data that will help to solve the problem, it's creating a simple and obvious solution. A friend has a start-up in the commercial air quality space which solves for this problem (in some ways). But the benefit isn't the air quality, it's the cost of maintaining the healthy levels required in commercial buildings. Air quality is the secondary benefit of reduced electricity demand in air circulation.
• fatata123 3mo ago
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• 0ckpuppet 3mo ago
  This sounds like a solution in search of a problem. If you feel dizzy at random moments, see a doctor soon.