The bottleneck might be the air in the room
blog.mikebowler.ca
blog.mikebowler.ca
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.
> 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) ...
Why only 2?
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.
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.
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.
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.
> 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).
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.
There’s a huge leap from that to the power consumption being low enough to be integrated into a smartphone, as demanded by OP.
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.
Not sure about that, at least NDIR sensors have to be at certain elevated temperature to work and they do some preheating when you turn them on from standby.
So it's not possible to just measure less often as then energy would have to be spent on heating the sensor.
They recently overhauled their lineup and replaced all Zigbee devices by Thread + Matter. Some of the new devices (mostly those who support TouchLink, e.g. some of the lights) have a secret pairing mode with which you can use them with Zigbee, but it's only a subset of the new products.
Uuh, seems not keeping up with social media finally backfired. That sounds horrible! So far IKEA been a great experience when it comes to HA+Zigbee stuff, and I started buying stuff relying on they'd keep just keeping up with that, really sad to hear they've changed course.
The "secret pairing mode" stuff sounds the same as currently/before though, but they only do so for a subset is new and hope they again change their mind.
If you already own the ikea hub, they secretly put thread radio in it which was just sitting unused in preparation for this range.
There are also strong downsides though, one is privacy and future cloud lock-in. Zigbee is fully local. Previous Thread standards added the option for NAT64 so that Thread devices can access the internet and there were some Thread + Matter devices that already require internet access for full functionality (IIRC some Nuki smart locks, but I might misremember). However, Thread 1.4 also adds support for Thread devices to get a globally routable IPv6 address. The Thread 1.4 whitepaper is pretty blunt about what this enables:
Simplified Cloud Integration: Thread devices can now seamlessly connect directly to cloud services, enabling remote control, monitoring, and over-the-air firmware updates.
https://www.threadgroup.org/Portals/0/Documents/Thread_1.4_F...
The fact that Thread and Matter are strongly pushed by Google, Apple, etc. should tell you enough.
Now, a TBR may simply allow you to disable NAT64 or globally routable IPv6 addresses (e.g. Home Assistant's addons), but many consumer implementations don't. E.g. the Apple TV is a Thread Border Router and does not allow disabling NAT64, so Thread devices can access the internet, send analytics, and can be cloud-controlled.
Also, the ecosystem is still pretty immature, as a result of which you can encounter issues, typically resulting in unstable device connectivity. E.g. TREL does often does not work well. Apple has some hacks to fix most of the issues, but it only works well between Apple devices. So it's generally the best to avoid combining multiple TBRs into the same network.
But I'm certainly not about to let simple IoT devices have any internet access at all. Being unable to block this on the TBR as you suggested would be mandatory for me, and not possible on AppleTV.
Better than what already exists and is deployed? I dunnno, hardware already in use always beat "hardware conceptually better but I don't have it", that's why Zigbee is better, for me. Protocols much like everything in the world, isn't correct/incorrect or universally "better", it's all down to use cases.
Personally, as someone who started to rely on IKEA providing Zigbee devices, Thread is obviously worse, because 100% of the devices I have are already Zigbee and not Thread.
It's a vastly better system and the transition period is so smooth because the smart home companies have been deploying the thread hardware for years before anyone started using it.
Also worth mentioning that many modern Zigbee radios can also be Thread thread radios using different firmware. There are even multi-PAN radios that can do Zigbee and Thread at the same time. Some smarthome hubs use multi-PAN (e.g. Homey Pro), but it's generally recommended against now because of lower reliability.
The same applies to devices, e.g. some of the new IKEA devices work over Thread or Zigbee (Zigbee pairing is triggered using a non-documented sequence, presumably they added support for TouchLink). Or e.g. the Aqara FP300, which can be flashed with Thread + Matter or Zigbee firmware. It works because the same radio can be used for both protocols.
It is a thermal conductivity sensor, which is a very indirect way of measuring CO2 and is very sensitive to environment factors. You only get somewhat good readings in lab conditions.
Don't by the ALPSTUGA for anything but very rough trends, there are much better affordable options.
Also in my experience it’s much more accurate than that.
Besides that, what's the point? There are much better meters in a similar price class. As an additional benefit, they can last months or up to a year on two AA batteries.
ALPSTUGA is an inferior product.
"oh no I am getting too much fresh air"
I get your point but come on.
At any rate, this is really a weird discussion, because you can get far more accurate meters at similar price points. Why waste your money on a much worse meter?
(Upd: the IKEA does have lower accuracy, with ±100 ppm instead of ±30 ppm. From the SEN63C datasheet)
If you want a CO2 meter on the cheap, either wire up an optical NDIR sensor like the SenseAir S88 (22 Euro) up to an esp32, which is possibly the best sensor you can get for the money (slightly cheaper version of the sensor that the AraNet4 uses). Or if you want something standalone with a display, get the SwitchBot Meter Pro CO2 for ~50 Euro, which uses a photoacoustic NDIR, but is still miles better than the sensor in the ALPSTUGA. Can also be hooked up with HA through an ESPHome BLE proxy or with the SwitchBot Hub.
You can find a comparison of the IKEA sensor with other affordable sensors here:
https://danieldk.eu/hardware/smart-home/ikea-alpstuga
(Upd: the IKEA does have lower accuracy, with ±100 ppm instead of ±30 ppm. From the SEN63C datasheet)
You forget to mention that it is ±100ppm plus ±10% of the ambient ppm, which makes a big difference. At 1000ppm it's ±(100ppm + 0.10*1000) = 200ppm and that's only in an environment with 25C, 50% RH, and 1013 mbar. So, that does not tell you much, given that thermal conductivity is very sensitive to environmental factors.
I dont need to know the exact level, just give me a green/yellow/red LED and make it cheap so I can have a sensor in every room
and if sometimes you ventilate a bit sooner than required, at 700, what?
businesses will not put $200 meters in every room
There are good $50 Euro meters. Besides that, I am not sure if that is true, at my wife's workplace, they put high-end CO2 meters in every larger room where multiple people meet. Admittedly, this was during COVID, so a lot of organizations were using CO2 levels as a proxy for finding whether a room was properly ventilated.
If it makes you feel better I don’t see a problem with it.
You can open the window for a bit to air out, should be done even in the winter :)
A price of 30 EUR makes this sensor really easy to pick up. For the same price as one Aranet (~180 EUR) the typical household can place a sensor in every room of the house. Which provides far more accurate readings for the whole house than just one high-end sensor in one room.
But when it goes over the safe limit it should be enough to decide to ventilate.
It can't be much, since the Aranet 4 can run for years on 2 AA batteries.
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
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.
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.
The place to look is existing codes for ventilation. Exempli gratia: https://dos.ny.gov/system/files/documents/2020/09/2020-mcnys... (see PDF page 46). Regulations to enforce outside air being brought into human spaces already exist.
I have been in some office buildings in United States which had CO2 monitors in each meeting room, and the ventilation would engage to control CO2 below a set level. We would entertain ourselves by exhausting our lungs onto the sensors to trigger the ventilation system.
In terms of outside air, a lot of US cities I think would not benefit from that, all that much. Especially during certain parts of the day, with a lot of smog.
But regardless, all that entered my mind was "Once employers are required to add any form of scrubbing, and perhaps O2 injection, they'll over do it for optimal employee output." Regardless of whether it's helpful once the employee leaves the workplace.
I'm not against this, I'm just actually saying the regulation should be locally defined.
Scrubbing indoor CO2 is sensible only when you want to go below the outdoor CO2 level, not at levels above it.
Best solution.
The rooms being discussed here are mostly ones which would have been built before this was taken more seriously. Classrooms, older office buildings, etc.
NYC is full of buildings which would never pass any code today but are still happily occupied. It’s a trade off, I think.
You don't need to make everybody aware, you just need to make the right people aware.
As for the State... Mine mandates that nobody can use the laptop's keyboard, they must use an external keyboard so the laptops' screens can be risen to eye level.
We have the external keyboards and the risers, and nobody uses them.
The State usually finds the worst and most wasteful solution available. Only fools trust the State to solve their problems.
IIUC they also need fans. The one I have in my home has one that's actually integrated into the sensor unit.
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.
The question is if oxygen levels are as good an indicator as CO2 levels... I suspect not.
You can hit this breathing by yourself in an unventilated 3x3m room (literally measured in my house).
I wonder how many driving accidents can be saved by having a co2 monitor in the car.
i have felt bad in high co2 environments before but i have never been in a controlled high co2 environment.
Which is the point: if you're in a room trying to do deep work, that's likely a problem. I suspect submarines are all over the place here: you might be exposed to higher levels routinely but you also have regular access to chemical scrubbers and decent ventilation. I'd be fascinated to know what levels are tracked as normal.
So quite possibly an adaptive response?
Probably. ISTR that depriving a body of oxygen results in a different response than overloading the body on CO2. It's why if you completely displace all air in the room with CO2, people choke, panic, etc, but if you use Nitrogen, people just keel over dead without realising it.
We evolved to detect CO2 because that's by far the easiest thing to detect that's still a reasonable proxy for the performance of our respiratory system
It's about pH. CO2 creates carbonic acid when it dissolves in water. Your blood pH, in turn, controls how much you feel like you need to breathe. So with high CO2, your respiration rate slows down, and that can lead to low oxygen levels.
Note that the physiology and biochemistry of this is complicated (e.g. blood is a very good pH buffer and it's actively regulated by kidneys etc) and it's very much a nascent field of research, so I think AI will be overconfident and hallucination-prone.
Source: I worked in high-co2 caves for my PhD so have read about this a lot. I always carried a CO2 monitor. Our rule was to get out if we saw 20,000 ppm or greater. I spent thousands of hours above 10,000ppm.
Pretty sure I learned the effect was the opposite (high CO2 --> slower respiration). Note that that was ~15 years ago when I would have read that. Maybe I just misunderstood, or thinking has changed.
edit: reading now I see I was wrong about this. Thanks for the correction!
It was the first time that I heard about them. These basically never happen if your body and environment are halfway decent, but they are important in exceptional situations.
But...oxygen concentration is essentially indepedent of CO2. We measure CO2 at part per million levels, whereas O2 is 20% of the air.
(In that context CO2 is surprisingly toxic given that 1000 ppm can impair mental acuity).
The goal of a gasoline engine's sensor is to accurately and precisely measure the point where O2 concentration reaches zero, so ambient air levels are not quite as relevant.
Clean air contains about 20.9% O2 and 0.04% CO2. At 2000 ppm CO2, which according to the author is bad enough to impair judgement, that's 0.2% CO2, it that CO2 is the result of respiration, it means that about 0.2% O2 was consumed, so that's a drop from 20.9% to 20.7%, a very small difference. 20.7% is not low enough to have a significant effect, the CO2 itself is the problem, not the drop in O2. And using O2 concentration as a proxy for CO2 doesn't look reliable to me: the difference is small and other things, like humidity can affect O2 concentration.
As for the sensor, O2 sensor in cars compare the O2 concentration between the outside air and exhaust gases, it needs outside air as a reference, but what you are measuring is the outside air itself, you don't have that reference.
I dont know anything about human respiration, but I know a little about chemistry and theres no reason to assume this is true. Basic stoichiometry.
According to a random article on the internet[1], nominal co2 production is 80% of oxygen consumption.
Your point appears broadly correct, just wanted to point out some faulty reasoning that could lead to incorrect results in the future.
[1] https://societymechanicalventilation.org/wp-content/uploads/...
Source?
It looks that some O2 sensors that don't require a reference have been used (titania sensors) but even though they have some advantages, they are less precise and mostly obsolete.
CO2 was measured with infrared but water also absorbed it, so you need to heat things up enough to not have water. It can be small, but not watch small.
All and all interesting stuff!
Can't you just measure CO2 "naively"; but then also, separately, measure rH; and then use the rH value to grab a research-calibrated LUT to pass the raw CO2 value through?
(I presume this is why all the little standalone CO2-sensor boxes you can buy also have rH displays. They're measuring it anyway to normalize the CO2 value, so they may as well make it a feature and display it.)
Maybe if it was ambient air and not breath the humidity might not be as bad?
And (maybe less realistically) what if the theater puts 5 Apple sensors inside a sealed CO2-free chamber, spread around the room?
Article author completely ignores this for the obvious reasons.
A sensor mounted in the office will get calibrated every night when the office is empty.
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.
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.
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/...
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.
I agree with OP. I don't always carry it along, but it has been a massive boost to my productivity.
The only issue this house had was it overheated. We had glass facing south. Even in winter it instantly became too hot.
HRVs only deal with temperature, but then you have humidity that is non-controlled: moisture coming in during the summer, and getting vented out in the winter (too-dry air coming in).
ERVs handle both.
The link I pointed to is all about ventilation, so just because people ignored an important component of building science, and focused on one aspect, does not invalidate it.
And while climate change is important and using efficiency to deal with it is useful, the thermal control layer is actually the least important of the four:
* https://buildingscience.com/documents/insights/bsi-001-the-p...
'Bulk' water (precipitation) and moisture can cause deterioration of the building materials (rot, crumbling), and also mold, which has its own health effects. Leaky houses can often blow conditioned air at much faster rates than thermal leakage.
- Plenty of people live or work in older buildings, where are not up to standard. For example: my office probably violates the air quality sensibilities of the Victorian era, which is when it was originally built.
- Equipment breaks down, isn't operated properly, or wasn't installed correctly. Having monitors that measure air quality is an extra check. While you may not be able to get direct action upon a consumer sensor, it can help you push for action.
I've been in buildings of varying quality over the years. I've seen how it takes time to get people in to do air quality testing. Heck, I saw the government claim that the air quality was acceptable in schools during the pandemic because the schools had passive ventilation systems. That meant they could open windows. (To be fair, the air quality in most of those buildings was probably fine since that was how the buildings were designed. That said, such standards make it easy for some buildings to slip through the cracks.)
So yeah, sensors to the people!
I've been involved with the build out of several office spaces in new and old buildings. We always took this sort of thing seriously and measured each room independently for a week (many at a time) ensuring we accounted for periods of high occupancy.
This let us tune the HVAC systems to operate more efficiently, ensuring comfortable temperatures and air circulation. Every time I've seen this done there were structural deficiencies that required remediation, some times it meant adjusting duct work.
Most modern office buildings are designed to be a platform for constructing spaces, as spaces usually evolve and change between leases and tenants. They're designed to accommodate this sort of thing.
However I've found that no build out nails this the first time. It's very hard! Often times things look fine but once you get people in the space things change drastically. It requires time and effort to address.
Several of my offices had such good air that I'd prefer being there over pretty much anywhere else -- even outside on poor AQI days.
I've also found that a lot of offices don't do any of this and their air quality is noticeably poor. And lastly I've found that the oldest buildings, including schools -- and I'm talking really old -- have very good air because they are so incredibly leaky. They're usually harder to cool and heat, though.
Whenever I travel, I bring a CO2 meter with me. It’s amazing how often the air is bad. Often in unexpected places. My meter hit 3100 in an uber once. I didn’t even notice until I got to my hotel room and looked at the data log. It was a fresh, hot day outside. The uber had windows closed and AC on. I bet he had no idea - but he was driving with significant cognitive impairment. Takeoff and landing in planes are always the worst. If you get sleepy as the plane is taking off, it’s not you. The plane’s ventilation doesn’t work properly when the plane is stationary. So before a plane is in the air, they often hit 2500.
Metrology calibration is necessary if you want accuracy better than 10%, but most of us don't care at all about that, instead we care about increments of 200ppm or more.
It’s like if someone said ‘you can check if your chatbot’s news feed is complete and up to date by asking it for ‘recent mass shootings’. There should be two or three in the past seven days’. It’s true and a valid methodology but holy crap does it say something dark about where we are.
Air quality should be good everywhere. But its not. You can't tell if you don't measure it.
Then all of the sudden Satish 2012 comes along and shows serious cognitive impairment at 1000 ppm. The only studies that have replicated this involved Satish. Studies without Satish as a coauthor fail to replicate their findings.
If you think about it for a second, the levels of impairment Satish shows don’t make sense at all. You’d expect to see differences on SAT scores of hundreds of points between test centers with good ventilation and bad. You’d expect to see massive differences between regions where AC is more or less common. Or even between seasons.
It is better to have it in the HVAC system than in your phone anyhow:
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.
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.
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)
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.
A lack of direct study might make "in front of your face" numbers harder to interpret in absolutes, but relatively speaking I do think that's the number which matters more. Whole-room analysis is just a proxy for the air in front of your face.
I installed a CO2 monitor at home, which reminds me of ventilation in winter when I keep windows closed and heating on.
It would be like the weather station telling you it was 160 degrees outside because they put their thermal sensor on the asphalt, but you wanted to know the air temperature.
I’ve done development on products with CO2 sensors and I’ve spent a lot of time with them on my desk right in front of me and also off to the side. Readings right in front of me are predictably higher.
You can breathe into a CO2 sensor 18 inches from your mouth and watch the values spike upward.
And, spoiler alert: if the entire area in front of you has an increased CO2 concentration, then your environment has an increased CO2 concentration. That’s the entire point.
Suffice to say I disagree strongly with both the argument that this would lead to hugely erroneous readings and also with the notion that people would panic.
I don’t think you’re reading the discussion: The CO2 thresholds that people use are based upon ambient air.
The closer the measurement to your mouth, the higher the reading will be. It should be apparent why putting the sensor directly in front of your mouth will register higher numbers than having it across the room.
CO2 does not instantly diffuse throughout a space. If it did, it would be sufficient to have only very small air leakage in a space for the CO2 to diffuse out of it very rapidly
The CO2 content is a single chemical species within a mixed gas. Any air currents will cause mixing. Otherwise it undergoes diffusion which is actually a fairly slow process, although much faster in gases than in liquids.
I would imagine it's still relative unlike temperature on the wrist (which is too affected by body temp)
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.
We’ve been studying the impact of CO2 for decades, at much higher levels than you see in office buildings and have never recorded any cognitive impact (until many thousands of PPM) until the Satish study in 2012 and a handful of other studies that Satish was involved in.
If you think about it for a second these studies can’t be accurate. If they were, you’d see differences on SAT scores of hundreds of points depending on building ventilation. You’d see huge variations between taking the SAT in the springtime when the windows are more likely to be open or in the winter.
You’d expect to see massive performance differences across nearly every metric between regions that use AC vs those that depend on opening windows.
And we do not see anything like that.
I tried keeping my room well-ventilated (500-700 ppm) for a few weeks and didn't notice much impact on sleep and work. There was a burst of positive effects a few days into the experiment but it didn't last and was likely unrelated.
The air definitely starts feeling stale and gross around 2000 to 3000, so I try to keep it below 2000.
That's all personal anecdote, but it similarly drives me to ask: Where's the replication?
Astronauts given two different batteries of cognitive tests showed no dose-response relationship to CO2 concentration
This sparked the panic about CO2 levels that led to people buying CO2 sensors and thinking that not unusual CO2 levels were actually destroying their ability to think. Many conclude that this has been happening all of their lives and to everyone around them who is unaware.
It triggered a lot of follow-up studies. Confusing, some of those (like the Harvard one everyone cites) included Satish, meaning they weren't independent despite coming from different organizations.
The really interesting thing is that many of the follow-up studies that don't include Satish have even used CO2 levels much higher than the 2012 study that caused the panic. Here is one I grabbed at random that went all the way up to 15,000ppm and failed to find any significant changes: https://pubmed.ncbi.nlm.nih.gov/29789085/
There was also a lot of CO2 research before Satish come along that failed to find significant effects at these relatively low levels. It has been researched in the contexts of air quality for submarines and space shuttles by militaries and NASA because keeping the crew of those operating optimally is important, clearly.
https://ntrs.nasa.gov/api/citations/20100039645/downloads/20...
My experience is more like being slightly drunk. If you know you need to be sharp (client meeting in a meeting room with shitty air), of course you can do it.
But when you have a relaxed team meeting in the same room, the jokes start getting really bad _really_ fast after the CO2 levels start going up.
Worse, when I brought the monitor home, I found the levels there were elevated even with no one home and surpassed 2000 with just two or three of us in a room.
The good news is that I stopped worrying about making my house "tight" for the sake of energy efficiency. I keep some windows cracked all year and don't worry about how tight the door seals are.
You could also install an energy recovery ventilation (ERV) system.
The point of having "tight" houses is not (just) about energy efficiency but about air quality as well. The general mantra is build tight, ventilate right. It's why modern building codes mandate air tightness and having ERV/HRVs.
By having a leaking house you do lose efficiency because in summer the air you paid to cool goes out and the hot-humid comes in, and in winter the air you paid to heat escapes and the cold comes in. But in addition to temperature (and humidity/moisture) you also get things like pollen, brake dust, (depending on your region) wildfire smoke, etc.
By ventilating right with ERV/HRV, you remove stale air and bring in tempered fresh outside air that you filter before distributing throughout the building. Air quality is also why 'spot ventilation' is also generally mandated at certain locations like over a cooktop/range in the kitchen, and in bathrooms (where the primary purpose is not taking care of smells (though helpful), but rather moisture from showers/baths).
* https://www.youtube.com/watch?v=CIcrXut_EFA
* https://www.youtube.com/watch?v=UTBNNhUH5V8
* https://www.greenbuildingadvisor.com/app/uploads/sites/defau...
How much does implementing all that cost? What degree of benefit does it offer over simple window in situations where those concerns are negligible? What other benefits to human life could be procured with that money?
It just boggles the mind that people feel emboldened to only look at one side of the equation.
> How much does implementing all that cost? What degree of benefit does it offer over simple window in situations where those concerns are negligible? What other benefits to human life could be procured with that money?
Everywhere not being LA is actually an argument for ERVs/HRVs. The weather in LA (AIUI) is fairly even and consistent and it is probably fairly easy to just open a window.
But if you're in Texas with high humidity, or Arizona with high heat, or north of the Mason-Dixon line where people get winter, it's kind of hard to open a window when it's 0 or -10 outside. If you have stale air (perhaps as measured by high CO2) what are you supposed to do?
Over the July 4, 2026, weekend it's supposed to get >90F/>32C on the east coast of the US: do you want to open your windows and let all of that heat in? Especially if you already have an AC unit so paid to run it get your home's inside temperature down?
If you have a place with ducts, you can purchase an ERV and tap into that for US$ 1000:
* https://www.hvacquick.com/products/residential/HRVs-and-ERVs...
or even less:
* https://hvacdirect.com/air-cleaning/erv-air-exchangers.html
And even in milder climates (like LA), have the ERV suck in air from the outside through an MERV 13(+) carbon filter, and not only do you deal with things like wild fire smoke, but wild fire smell:
* https://www.greenbuildermedia.com/blog/wildfires-make-indoor...
* https://shop.aprilaire.com/products/aprilaire-513cbn-odor-re...
It is possible to make your indoor air cleaner than the air outside.
1. Not living in a city (polluted or otherwise) still does not solve the problem of letting out cooled air and letting in hot-humid air in the summer, and letting out warmed air and letting in cold air in the winter. If your CO2 is high are you going to crack open a window when it's -10 outside? Or in the middle of a heat wave (esp. if you have AC and paid to run it to cool your house).
2. Not-city living also has pollen and other allergen leakage. You're also more likely to get wild fire particulates in less urban areas.
Building tight and ventilating right is applicable in all locations and all climates.
And in the extreme case, if you believe the outside is the healthiest environment, live in a tent or under a tarp. :) Buildings were invented to have a separate outside and inside, and leaky houses reduce the effectiveness of that separation.
Your indoor air should enter through windows or intentional intakes, not incidental gaps.
Small cracks are also things that critters may be able to get through.
Only a couple studies purport to show cognitive changes at levels around 2000ppm, and the ones I know of all involve one controversial researcher named Usha Satish.
There are a lot of studies with CO2 levels at 10,000ppm or higher that have failed to find cognitive effect (an example https://pubmed.ncbi.nlm.nih.gov/29789085/). Your 2000ppm classroom air would have been like fresh air relative to the concentrations these studies are looking at.
I see this pop up on X every few weeks. Is the concern about this really based on actual science? Is there empirical data proving people are less productive or are damaging themselves as a result of heightened CO2 levels? And I don’t mean observational epidemiology studies.
So perfect for HN, you can obsess over numbers and tech and how to measure it endlessly and overhype the significance to trick yourself into thinking you're doing something useful.
You get to have your cake and eat it, no wonder everyone loves this topic.
(Also if you're a doomer type you can link this in with rising atmospheric co2 levels for extra points)
Meanwhile in France we heat classrooms by stacking 35 kids in a confined space. It saves on heating, plus condensation that makes windows opaque helps pupils concentrate on the blackboard, as teachers said during my childhood.
That sounds like something you made up to justify your beliefs…
The average male height in France is 178.60 cm, while in Australia it is 178.77 cm:
* https://worldpopulationreview.com/country-rankings/average-h...
Some sources even have France being higher than Australia:
But also bear in mind that regardless of "are we operating at max effectiveness", OSHA sets a legal limit of 5000ppm in a workplace, and that's about _safety_.
This article is talking about keeping levels below 1000 which is a very high standard IMO (still arguably justified given the studies mentioned). But if you are in a poorly ventilated home office you could easily hit 3000. At that point you are closer to "illegal in the US" than "earth's atmosphere".
So yeah even if you are unconvinced about micro-optimising your CO2 levels there's a very long established argument in favour of at least paying _some_ attention to it.
The real problem is offices and meeting rooms where you have 10 people in a small box for hours and windows that don't open.
I live on a noisy street so I don't usually want to do that, if I open a window at the back and keep internal doors open it will stay reasonable but significantly elevated.
So yeah I think the lesson here is you probably need to buy a sensor, different homes are gonna differ.
My home is quite small (probably 80m²) and has literally zero ventilation built in (even in the bathroom!). I live in Switzerland where it's traditional to actively ventilate your home twice a day. But that doesn't do anything for CO2. Also it's such a fucking waste of time lol. Looking forward to moving into a modern building.
So maybe a few leaky cracks are enough that when you open a window you get a bit of a through-draft.
Also go for a walk, unless you live in a hellhole.
In a bedroom it might be worse than the elevated CO2 problem.
Is that really dramatic, or just the reality that needs to be considered in a cost-benefit analysis? Are you a hay fever truther?
I'm certain many people are sleeping in similar conditions without realising and ventilating their rooms properly or leaving the door open.
Depends if you live where there is pollen.
Depends if you generate your power with solar.
Also, moved all of my lovely oxygenating plants like lillies out of the room because they are toxic to kitty.
It absolutely does.
>I'd just accepted for the longest time that waking up groggy with a slight headache and tired was the norm until I put a CO2 monitor in my room. With the door closed, it climbed up to 1500ppm in under an hour.
Same experience here. Opening windows just a bit totally changed my sleep quality.
You'd think (hope) if there was a big effect here on performance, the relatively cheap/easy solution of maintaining lower CO2 would be standard. I know people think of the military as dumb grunts who you don't want to think, but he was one of the four department chiefs onboard (Weapons, Nav, I forget the others) and they have pretty substantial responsibility to make decisions on their own.
Along the way they’ll either learn about or accidentally mitigate other ills like radon, nitrous oxide from stoves, diesel particulate’s impact on test scores, etc.
It kind of reminds me of the old joke where a drunk is looking for his keys under a street lamp even though he dropped them in a dark corner of the parking lot.
I am suspicious of 0.1% having a significant effect though, given oxygen is around 20% and we naturally exhale a couple of percent CO2.
So in practice the oxygen level can never drift meaningfully far from the atmospheric pressure, whereas carbon dioxide easily can because the pressures involved are so low.
But then why can we see problems with concentration in studies of people in poorly ventilated rooms, but not replicate that when just adding CO2 to normal air? What is the CO2 that we can measure in meeting rooms actually a proxy for?
This original study has been used to market these CO2 monitors for years, but the evidence is quite thin and doesn't support a strong effect. It seems likely that there is a small effect, and it has been wildly exaggerated thanks to a small study with N=22.
Robert Boyle describes Drebbel’s use of a “chymical liquor” to refresh the air.
“Paracelſus, indeed, tells us, that "as the ſtomach concocts the aliment, "and makes part of it uſeful to the body, rejecting the other; ſo the "lungs conſume part of the air, and reject the reſt." Whence, according to him, we may ſuppoſe a little vital quinteſſence in the air, which ſerves to refresh and reſtore our vital ſpirits; for which purpoſe, the groſſer, and far greater part of the air, being unſerviceable, it is not ſtrange that an animal ſhould inceſſantly require fresh air. This opinion, indeed, is not abſurd; but it requires to be explain'd and prov'd: beſides, ſome objections may be made to it, from what has been already argued againſt the transmutation of air, into vital ſpirits. Nor is it probable, that the bare want of the generation of the uſual quantity of vital ſpirits, for leſs than one minute, ſhould be able to kill a lively animal, without the help of any external violence. And, upon this ſuppoſition, Cornelius Drebell, is affirm'd, by many credible perſons, to have contrived a veſſel to be row'd under water: for Drebell conceiv'd, that it is not the whole body of the air, but a certain ſpirituous part of it, that fits it for reſpiration; which being ſpent, the remaining groſſer body of the air, is unable to cheriſh the vital flame reſiding in the heart. So that, beſides the mechanical contrivance of his boat, he had a chymical liquor, which, by unſtopping the veſſel wherein it was contain'd, the fumes of it would ſpeedily reſtore to the air, foul'd by reſpiration, ſuch a proportion of vital parts, as would make it again fit for that office; and having made it my buſineſs to learn this ſtrange liquor, his relations conſtantly affirm'd, that Drebell would never diſcloſe it, but to one perſon, who himſelf told me what it was.“
https://sourcelibrary.org/book/philosophical-works-vol-2-boy...
https://danieldk.eu/hardware/smart-home/esphome-senseair-s88
If you want something with a display that works on batteries without spending over 200 Euro for an AraNet, the SwitchBot Meter Pro CO2 is pretty good option. It is regularly on offer below 50 Euro. It uses photoacoustic NDIR, but does not deviate a lot from the S88. You can use it without a SwitchBot by configuring it with a phone on Bluetooth. The meter works on external power and battery, but even when on battery, you can set the reporting interval to 5 minutes, which is good enough in practice. The meter broadcasts the measurements with Bluetooth LE, so if you want to get the data in Home Assistant, you can place a ESPHome Bluetooth LE Proxy in the vicinity [1]. This is an ESP32 flashed with ESPHome that listens on Bluetooth LE advertisement and forwards them to your HA instance over WiFi. Of course, you could also get the SwitchBot Hub, but what is the fun in doing that? :)
I would avoid the Ikea ALPSTUGA, it uses a thermal conductivity sensor, which is a very indirect method for measurements and it's often several hundred ppm off.
Will look at adding the CO2 monitoring
Edit: actually, they only sell them as part of a 6-in-1 device, with a display, and a bunch of other sensors. That feels overkill, I wish they would just sell the CO2 sensor itself
I wish they would sell just the CO2 meter, like this one: https://www.switch-bot.com/products/switchbot-indoor-outdoor...
Looks like it's increased in price unfortunately but I like the idea, it's basically just what you would do as a DIY project but ready built. So you can either use it like a normal commercial product, or you can just fork the ESPHome config that's on GitHub and flash it exactly like any normal ESPHome project.
https://screek.io/ https://shop.screek.io/products/sco-b
No recommendation though, I haven't tried them.
It's a extremely cool that ESPHome is able, just by existing and being good, to create this little industry of no-bullshit products. What an awesome project that is!
They do have a gateway product, but it’s not necessary if you have HA. If Apple homekit routers supported BLE as source it would work seamlessly in the ecosystem, but a bridge software is required on HA.
https://www.pangram.com/history/c410d4b4-abfd-4ca0-b52d-db0d...
This post evaluates to 99% AI generated.
That's valuable in at least three different ways: public education, showing that most of the articles are still human-written which can be easy to forget about sometimes, and as an easy way to cross-validate my intuition when flagging something as AI-generated without having to manually run Pangram.
I despair a little bit about how many HN voters either seem to want to read slop or don't understand when they're reading it. This post is obviously AI generated from the first paragraph on, and still has 480 votes.
They train a classifier on human text paired with AI-generated versions of the same documents. Dataset scale is comparable to LLM pretraining sets.
Generally it’s a miracle to me so many people survive traffic on public roads, statistically.
Of course some things are more hilarious than others :)
>Cars aren't hermetically sealed
I can agree with that completely.
Not my downvote btw, corrective upvote instead :)
Naturally I often wonder if many people know what Hermetically sealed is all about to begin with.
I do a bit of that in the lab when I seal flammable reference materials inside glass ampules using a torch. But it's not the sealing that counts, it's the technique ;)
If you check Wikipedia, you may notice that the terminology is older than the internet in every way.
Specifically they do not show awareness that it really means "sealed in such a way that it can't be figured out. As if by God. Not just any God but the ancient Roman God Mercury, otherwise known as Hermes when worshipped by the ancient Greeks."
Now I can only assume you have never been in a new 1960's WV beetle when all windows and the manual vents were shut (they didn't have A/C) when somebody slammed the door. You eardrums would remember it if so.
They're just not that sealed up.
At the extreme was "MAX" which most people didn't realize was "recirculate" unless they read the owner's manual in those cases where it was well documented. The next notch over was "NORM" which as the name implied was intended to be the "normal" setting except under more challenging conditions. But with fresh air coming in constantly it only was passing through the refrigerant coils one time, plus sometimes the outdoor air is a lot hotter than others, so recirc is when you want the same interior air to pass through the coils more than once.
All this may go "out the window" when the exhaust fumes or worse in the outdoor air need to be excluded as much as possible.
I kind of miss the old '70's cars even though loads of them kept running long after the A/C had failed.
Regardless, I never felt alone even without a passenger, with my good buddies Max & Norm with me everywhere I went ;)
IKEA now has a remarkably cheap ($35) air quality monitor that measures CO2 as well as PM:
https://www.ikea.com/us/en/p/alpstuga-air-quality-sensor-sma...
I don't have one yet but plan to pick one up soon. A CO2 sensor alone from Adafruit is $50+, though that one is more precise. I bought it a while ago and it's still sitting in my todo bin.
The first needs to occasionally see new threats to stay up to date and healthy. The second will not like the constantly restricted airflow.
For instance, I'm now really only sure that author measured a 2000 ppm CO2 in a meeting room once. Everything else could just be LLM trying to invent convincing argument.
The worst thing is, I'm pretty sure humans are starting to mimic that cadence too...
https://www.pangram.com/history/c410d4b4-abfd-4ca0-b52d-db0d...
Feels like I wasted time reading bullshit.
In Quebec province in Canada, they added CO2 sensors in all the classes in all the schools after covid. Now what? Having data does not change anything if nothing is done.
If instead all the millions invested would have gone into adding air exchangers, now that would actually do something.
And that is assuming that CO2 levels really have an impact. From the last time I researched the subject, I found that there were few studies showing an impact.
For context, from what I remember, in submarines the CO2 levels are usually between 10 000 ppm and 20 000 ppm. Very far from 1000 or 2000 ppm.
Also, CO2 sensors are usually pretty bad. I work in HVAC and I hate calibrating them, the readings are not very consistent. Leave them alone for a few years and a good percentage will simply output bad readings.
Then you see things like a teacher leaving the windows open in winter because the sensor says 2000 ppm all the time instead of realizing the problem is the sensor. (CO2 levels should go back to atmospheric levels over the weekend for example at about 450 ppm)
The ISS runs at 3000-6000ppm CO2. over 7000 is dangerous
I found 3-11k as regular levels, with no impairment known of. So acclimatization can happen?
I got one because old apartment and bad ventilation. Was able to open a window when I felt the effect before, but now I can get an alert earlier. Since getting it I could consistently feel the effect at around 11100-1300.
You cannot solve a problem when you don't know you have a problem.
I swear I can feel the 430ppm already. I was born into a world with 340ppm. I can't imagine what it's going to be like when we hit 500+ globally.
I'm in the market for an active CO2 scrubbing solution that I could deploy at home. Scrubbing the entire planet won't work but I could make a small room feel like 1960 again.
Also, when you cook on a gas stove, it produces numerous other toxic gases which too are critical to ventilate before they even escalate, failing which the lung cancer is risked.
Scrubbing indoor CO2 is sensible only when you want to go below the outdoor CO2 level, not at levels above it.
You’re probably about my age, then, and I’m old. It might not be the baseline CO2 levels. :-)
Kidding aside, that would be hard thing to baseline.
The article talks about "within the hour". With four people in my living room doing normal things it jumps within 20min to around 1000ppm. If I am wrestling with my kids much sooner.
In offices companies often neglect it.
edit: if you are cooking on gas it also has an immediate effect on co2 of course apart from other small particles
A good way to think about CO2 is as a proxy for dirty air. CO2 is easy to measure but what it really means:
The next breath you take has: - already been inhaled and exhaled by others several times. - contains remnants of their farts, burps, off-gasing from everything they are wearing, have, everything in the room, etc. - may have presence of other gases like radon in the winter, mold spores, g-d knows whatever else. - co2 itself has negative effects but mainly it's a signal of what else is probabilistically in your air, poor ventilation.
Florence nightingale the inventor of modern nursing wrote that making indoor air as close as possible to outdoor air (without freezing the patient) is the best and most overlooked input to wellness. I believe this is still true.
Weirdly there are people who for some reason are hell bent on denying the air quality as an input to health and cognition. The simplest way to reason about it is: the argument for organic food is the less toxin-like stuff in it the better. Same for filtered or spring water. We often fail to quantity the impact exactly but we (logically) know that less toxin is better. For some reason we hold a much higher bar for "blaming the air" which doesn't make sense.
By volume we consume exponentially more air than food or water, and it enters the blood stream faster and more directly so obviously it impacts us. The EPA ranks indoor air quality as a top risk.
Ironically we are obsessed with outdoor air quality and if you have allergies to things like pollen that's a real concern but in most cases outdoor air is the baseline for what's indoors + other shit is added.
I find that there are people who say "wow air quality here is bad" and there are people who say "oh man I'm tired lately" without being able to attribute it, but I don't ever see anyone thriving in what is objectively bad air.
Study 1 (Simulated Office): Participants in optimized "Green" and "Green+" office environments scored 61% and 101% higher, respectively, on cognitive function tests compared to conventional office environments.
Study 2 (Buildingomics): In a real-world analysis, occupants of high-performing, green-certified buildings had 26% higher cognitive scores and slept better than those in high-performing but uncertified buildings.
Home/Work Study: Researchers tracking remote workers found that suboptimal indoor temperatures and elevated CO₂ (indicating poor ventilation) directly harmed creative problem-solving and cognitive processing.
Stoßlüften.
but then germany hasn't been doing so well lately, and people who do most of their work outside should also be doing better...
CO2 is just a tip as office or home is toxic environment anyway. Plastic (e.g. carpets), formaldehyde in furniture, air fresheners… add home office and cooking at home (-> small carcinogenic particles)…
If you start reading How not to die by Michael Greger, you find out that dust, soda and sitting - not CO2 - are real killers…
It's similar to how people think sharks and airplanes are the biggest killers - when in reality it is coconuts, mosquitoes, and motorcycles.
Dust is much more likely to just settle on the ground and be kicked back up than it is to move all the way to the purifier to get stuck in the filter.
One of them seems to have much worse ventilation to the extent that it reaches double the level. Opening the window slightly 24/7 keeps it low.
My fiance's chronic headaches/migraines/idk became noticeably less frequent after this change and when they do occur it's usually because the window was accidentally left closed.
Anybody who struggles with this kind of thing might want to try checking their levels. Or just open a window I guess?
I imagine it could easily be compensated by an equivalently minor increase of breathing rate or breathing depth.
[1] https://en.wikipedia.org/wiki/Gas_exchange#Alveolar_air
[2] https://en.wikipedia.org/wiki/Breathing#Composition
[3] 5/6 × 40000 ppm + 1/6 × 500 ppm = 33417 ppm; 5/6 × 40000 ppm + 1/6 × 5000 ppm = 34167 ppm; 34167 / 33417 = 1.0225
After testing a variety of AQI sensors, I ended up acquiring multiple Airthings-branded devices.
They provided the best mix of CO2/VOCs/PM sensors in a single device with a decent enough app.
There may be better options now, but I have these at both home and office.
Highly recommend doing the research and learning about the environments you’re in, especially if you have little ones at home.
Edit to add: opening windows is usually the easiest/best solution!
https://science.nasa.gov/earth/explore/earth-indicators/carb...
I also attended liturgies at church all the time, and let me tell you, there is no CO2 machine like faithful Christians packed into a little chapel who are all singing for 90 minutes, and standing shoulder-to-shoulder. I was absolutely desperate to stay awake during those times, and I knew instinctively that it was an issue with the CO2/O2 mix in the room, and I was personally the most sensitive to it, being extremly sleep-deprived, but I am certain that many others felt the physical adverse effects, without being cognizant of what was causing them.
I still suffer from sleep deprivation today, and when I settle in to our chapel of silent prayer, I often find myself nodding off uncontrollably, and it's so frustrating because I want to be alert and actively praying, but the environment is just... so relaxing. There are only about 4-5 other humans in the room, so the genesis is basically just me relaxing in a sitting, quiescent pose for a significant amount of time. I believe that the room is well-ventilated, but are they constantly recirculating air? The air outside can be 115 degrees; are there active intakes that must cool this hot, dry, dusty air? That's a lot of work!
My father having worked in Environmental Health & Safety, I became fairly good at recognizing hazardous or troublesome situations, especially indoors and with large numbers of people. I try to avoid getting embroiled in them, and it usually does no good to try and alert any supervisor or management about the issues, but this blogger is right; we must raise awareness and take action.
If your CO2 levels are that high then you should fix the HVAC system and get it up to code or lobby for fixing the code. In many countries, a full air exchange in any office space every X hours is mandatory. In other countries that's optional and they need to get their act together.
I visit a friend in Sweden the other day. Her house was built in the 80s, nothing fancy, a simple one family house. There is a ventilation system integrated. Every room has an inlet and the air is sucked out of the bathrooms and kitchen. Even has a heat exchanger. It's a pretty simple system: no cooling and it's not really used for heating except for pre-heating the incoming outside air with the energy in the exhaust air. But it exchanges the houses air multiple times a day. She told me this has been standard there for decades. A few ventilation pipes integrated into the houses construction and that's it. It's even mandatory in multi tenant houses to check air flow every few years.
It's not just the AC crazy US where HVAC is standard. It's just common sense to have such a system if you care about your health.
Even though this article is conveying good (and useful) information, it seems to be completely AI-generated.
Pangram clocks it as 100% AI: https://www.pangram.com/history/c410d4b4-abfd-4ca0-b52d-db0d...
Someone else in the thread lists it as 99%: https://www.salahadawi.com/hacker-news-ai-detector
Also, it sort of jumps out at you if you're used to reading AI writing. Claude loves to start paragraphs with "Here is the uncomfortable part".
I'm not necessarily saying this automatically makes it bad, but everyone should be aware of the source of their information.
Maybe it's not just the air but also the multi-hour meetings that drive people to a sense of "oh god let this finally end now", which leads do decisions that fall short.
Personal opinion, you can see cognitive decline at 1000 ppm. Not “ur a zombie” but it’s there. Airflow has vastly improved my life.
Another personal opinion - the coporate stupidity and inane behavior we all see tracks back in part to Co2 levels turning people into quasi zombies. It’s a lot easier to just not care, and things don’t click like they should, when in higher Co2 environments - pushing everyone to rote, process, unthinking approaches. Sounds familiar?
I didn't gather concrete data on this but this is just what I eyeballed over the last few years. Does anyone know why could this be the case?
BTW, that's also how stove pipes work - vertical column of air hotter than surrounding accelerates well and creates a strong airflow feeding the fuel. But if the pipe is thermally conductive, that air will cool down and won't flow, for hydrocarbon fuels it can also condensate water, that could extinguish fire underneath it. So, pipes are made insulated enough for strong flow.
Interestingly the Inkbird and the SCD4X quite often diverge by anything up to hundreds of PPMs; I kind of back the SCD4x (on a Pi in my case) for accuracy after lots of experimentation, reading the datasheet and ensuring the correct calibration procedurs are followed (basically expose the sensors to outside air once a week).
It's also interesting how much it varies day to day in my one-person office - possibly down to how windy it is outside, even with windows closed one day it never goes about 800ppm, other days it'll hit 1500ppm by lunchtime if I don't open a window.
N.B. Quite possible the Inkbird uses an SCD4x internally, seems reasonable kit so I have no explanation for the differences in readings.
https://www.ikea.com/au/en/p/alpstuga-air-quality-sensor-sma...
In most office buildings (towers) that's impossible. You have to deal with what the A/C gives you.
i've taken a few Amazon-listed CO2 meters from $dirt-cheap to $150, tossed them in a ziplock, and then discharged CO2 from a canister into the bag & sealed it. none of them read notably differently after an hour, nor show any sort of range error, etc.
i've also done this without the ziplock: put them in a large pot, fill that with CO2. CO2's heavier than the rest of the air so the concentration should remain elevated within the pot, but same deal.
i like the idea of monitoring CO2, but it's hard enough to get certainty about the _effects_ of CO2 level; without confidence in my meter i fear the conclusions i draw from it are more noise than signal.
Also, take walks. I am lucky to be able to walk to and from work and it helps immensely.
I watched the sensor rise from 800 to 1700 PPM by the time the last group left the
It’s quite easy to build one and deploy with esphome and breadboard with stuff you can order on Amazon and have an LLM walk your through hardware and setup.
It is interesting where the rate of speech quickens as the co2 rises and the body starts to notice the co2, or maybe that was just the coffee.
If you notice, that monitor has a "traffic light" gauge at the bottom to tell you if the current CO2 level is critical. That traffic light is currently showing RED, i.e. highly critical.
The thing is essentially sounding the alarm and prompting immediate action. However, became the traffic light colors are printed on and static and the only dynamic indicator is a small e-paper bit above the color gauge, the effect gets lost completely.
I’m guessing if someone had their air go through a conservatory first it could go lower.
In some climate YouTube videos people slip in the CO₂level of when they were born, an interesting point, mine was 325, but I guess there was more lead in the air then…
Is there much of an improvement, impractical as it is, to a far lower CO₂ level.
You will take ~ 1000 breaths per meeting hour. really gross!
People should probably get used to opening doors and windows more. Sure for some people there's noise problems (kids in the house, or outside environment being noisy) but there's also a lot of people who just don't know better even if they are in a perfect environment to open windows in (e.g. no noise outside).
It's on my desk and I can confirm, opening the window if it gets orange helps a lot with thinking.
Some days in the morning it shows red and I barely can't think or get awake. Opening the window and it changes instantly.
I once woke up with the fam in a hotel with airco at 5500 ppm. It is then that I learned the airco does not blow fresh air (logical after thinking about it).
but Ikea now makes the most affordable PM2.5+CO2 sensor, at $35 a no-brainer
https://www.ikea.com/us/en/p/alpstuga-air-quality-sensor-sma...
in there is a very nice/expensive Sensirion SN63C sensor that costs nearly as much as the Ikea itself
https://sensirion.com/company/news/press-releases-and-news/a...
unfortunately Ikea requires Matter network not plain wifi for communication so I've been looking for a cheap Matter hub or DIY SPR
Comprehensive AIR monitor system is must to get most efficient output. Author is right here!
I heard a Freakonomics podcast recently with similar takeaways - that air pollution has a direct effect on cognition skills.
Support European!
A possible cayalyst for compromised decision-making during crowded meetings :\
Central ventilation system at my job can handle open windows. So that is prohibited :-(
Why that matters? You need good ventilation regardless, but instead of just thinking of CO2, try to minimize compounds in your air by selecting things for the room that smell less and off-gas less.
Natural CO2 in a room probably correlates strongly with other things given off by humans... Farts, water vapour, viruses, etc.
The effect needs to be properly understood before totally redesigning the nations ventilation systems on a possibly wrong premise.
Perhaps using non-ozone negative ionizers would also help.
Either AI, or LinkedIn brainrot.
Not to talk about the weather either.
As other commenters noted, it's more about dirty air than CO2 levels - so, logically, should not be a problem for everyone.
If article is really written by AI though, then what if it's PSYOP? The question to ponder then is: why AI wants low CO2 levels? Maybe, for people like Sherlock Holmes to lose a concentration of thought?
A terrible way to make decisions.
Put it this way do you need to book a 3h meeting with your spouse to decide if to buy a house? Nope all the research and decision criteria were in advance. That final minute of making the decision is a cross check over that work.