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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

#401

Post by ludicrousdispla »

zh3 wrote: post #69

For the DIYers, it's simple to get an SCD4x sensor and hook it to a pi, arduino, ESP32 etc (then use CC to create a live web interface). I did this after trying an Inkbird CO2 monitor, which gets reasonable scores in reviews and wanting a live web report in the office. 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 accu…

I've been using an Inkbird CO2 monitor for a while, and it's definitely accurate enough for my needs.

Re: The bottleneck might be the air in the room

#402

Post by foobarian »

deanc wrote: post #13

I’m not saying this isn’t a legitimate concern but this really seems to have exploded amongst the tech community as the next obsession. 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.

I feel like it exploded after the cheap integrated sensors came on market that were easy to DIY with. It's nerd catnip, it makes you feel like you're discovering some hidden truth and makes it very tempting to blame the readings for all sorts of things. I don't even know how to trust the calibration on these things.

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.

Re: The bottleneck might be the air in the room

#403

Post by avazhi »

Aurornis wrote: post #352
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…

> 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 oth…

CO2 does not stream out when you exhale like a fluid. It’s a gas. It dissipates quite immediately and behaves as all gases do - it expands to fill its container via something like Brownian Motion.

Re: The bottleneck might be the air in the room

#404

Post by 317070 »

pieterhg wrote: post #268
hydevito wrote: post #263

Earlier quoted context omitted.

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…

This was probably CO not CO2? A CO2 monitor doesn't "go off", it just silently reports. CO would go off because it's deadly to have a CO leak.

My portable CO2 monitor goes off. You can set a levels of warning on the aranet. It is a very quiet, non-disruptive alarm, but an alarm nonetheless.

I agree with OP. I don't always carry it along, but it has been a massive boost to my productivity.

Re: The bottleneck might be the air in the room

#405

Post by Aurornis »

avazhi wrote: post #403
Aurornis wrote: post #352

Earlier quoted context omitted.

> 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 oth…

CO2 does not stream out when you exhale like a fluid. It’s a gas. It dissipates quite immediately and behaves as all gases do - it expands to fill its container via something like Brownian Motion.

Dissipation does not happen instantly.

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.

Re: The bottleneck might be the air in the room

#406

Post by 0ckpuppet »

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…

This sounds like a solution in search of a problem. If you feel dizzy at random moments, see a doctor soon.

Re: The bottleneck might be the air in the room

#407

Post by fc417fc802 »

avazhi wrote: post #403
Aurornis wrote: post #352

Earlier quoted context omitted.

> 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 oth…

CO2 does not stream out when you exhale like a fluid. It’s a gas. It dissipates quite immediately and behaves as all gases do - it expands to fill its container via something like Brownian Motion.

Actually what you exhale is a fluid.

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.

Re: The bottleneck might be the air in the room

#408

Post by avazhi »

Aurornis wrote: post #405
avazhi wrote: post #403

Earlier quoted context omitted.

CO2 does not stream out when you exhale like a fluid. It’s a gas. It dissipates quite immediately and behaves as all gases do - it expands to fill its container via something like Brownian Motion.

Dissipation does not happen instantly. 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.

I generally have fans around, but I too use a CO2 detector in my home and have tested it in various places and situations. CO2 concentrations are not as localised as you are making them out to be. If they are elevated in front of my face, for example, I can also similar numbers just above and slightly behind my head. If you go outside and do it, you’ll be surprised that the number doesn’t move really change at all when at arms’ length. Airflow is really everything here.

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.

Re: The bottleneck might be the air in the room

#409

Post by Melatonic »

Aurornis wrote: post #352
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…

> 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 oth…

Mostly agreed but with that much data couldn't we easily have an adjusted CO2 number for local sensors ?

I would imagine it's still relative unlike temperature on the wrist (which is too affected by body temp)

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