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The bottleneck might be the air in the room

blog.mikebowler.ca

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Re: The bottleneck might be the air in the room

#71

Post by hypfer »

throwaway81523 wrote: post #7

Don't forget too, if the CO2 is 1000 ppm, then half of the air in each breath you inhale was recently exhaled by someone else. Yes, airborne viruses are still spreading. I still wear an N95 mask whenever I'm in an indoor space with other people outside of home. 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 d…

Doing that all the time might not be the best idea for your immune system and neither for the respiratory one too.

The first needs to occasionally see new threats to stay up to date and healthy. The second will not like the constantly restricted airflow.

Re: The bottleneck might be the air in the room

#72

Post by Terr_ »

eitau_1 wrote: post #49

Can someone provide an explanation why CO2 concentrations above 1000 ppm have such a negative influence given the fact that CO2 concentration in lungs (at rest) never falls below 10000 ppm?

I'm not a doctor, but I would consider it in terms of flow and throughput, rather than,—metaphorically—the amount of water the pipe can hold.

Re: The bottleneck might be the air in the room

#73

Post by gwd »

I noticed this effect really strongly at university. There was one particular lecture hall that was effectively buried in the side of a hill; I can't count how many times I had an early afternoon lecture in there (so it had been in use since 8am), where I just could not focus or stay awake. Assuming sleep deprivation was the problem, afterwards I'd head out and lie down on a bench to take a nap, only to find myself wide awake. I have no trouble taking cat-naps when I'm actually tired, leading me to eventually conclude it was CO2 / O2 in the room that was the culprit.

Re: The bottleneck might be the air in the room

#74

Post by [deleted] »

Liftyee wrote: post #47
legulere wrote: post #33

Earlier quoted context omitted.

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.

I would hesitate to say the IKEA is worse. Inside the IKEA is a reputable Sensirion all in one sensor module. It's much cheaper and smaller because the CO2 sensor in it is using different (newer) technology that only released a few years ago from Sensirion. (Upd: the IKEA does have lower accuracy, with ±100 ppm instead of ±30 ppm. From the SEN63C datasheet)

[deleted]

Re: The bottleneck might be the air in the room

#75

Post by progval »

p-e-w wrote: post #57
Gigachad wrote: post #37

Earlier quoted context omitted.

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. I…

> 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.

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-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.

Re: The bottleneck might be the air in the room

#77

Post by stein1946 »

gpt5 wrote: post #6

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 room, get alerts, etc. and the problem will just solve itself. 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.

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

Re: The bottleneck might be the air in the room

#78

Post by embedding-shape »

odiroot wrote: post #70
Gigachad wrote: post #37

Earlier quoted context omitted.

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. I…

Can it work with Zigbee network or is Matter/Thread required?

I'm using a bunch of IKEA's "smart home" stuff, all via Zigbee+HA, works great. Look for the Zigbee icon on the package, and the pairing for Zigbee vs their own home controller might have slightly different pairing sequence on the device, otherwise it just seems to work.

Re: The bottleneck might be the air in the room

#79

Post by anon7000 »

ErroneousBosh wrote: post #54
Terr_ wrote: post #42

Earlier quoted context omitted.

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 pro…

> 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.

It makes a lot of sense actually. You get severe symptoms when CO2 makes up only a couple % of the air. And can become fatal at like 5%. There’s not like a hard line where you suddenly die, it’s a gradual thing. It very much makes sense that we’d notice minor symptoms at a few thousand PPM when it only takes like ten thousand to feel it severely.

Re: The bottleneck might be the air in the room

#80

Post by Aperocky »

This article is rated 100% on my AI smell meter, making it less trustworthy despite convincing arguments.

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.

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