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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

#191

Post by spockz »

nok22kon wrote: post #128
microtonal wrote: post #111

Earlier quoted context omitted.

No, it's not. You generally want to ventilate an office when you reach 1000ppm, but then the IKEA will often warn you already at 700ppm. 700ppm is fine.

you assume that the error will always be in one direction and if sometimes you ventilate a bit sooner than required, at 700, what? businesses will not put $200 meters in every room

Presumably there is still the need to ventilate. So the concentration can also be measured more centrally. That is how the mechanical ventilation unit in my house works. For both humidity and CO2.

Re: The bottleneck might be the air in the room

#192

Post by Yajirobe »

I have a CO2 monitor and I don't understand one thing - it seems that CO2 increases more quickly during summer than during winter. If I close my windows it takes longer to reach 1000 ppm during winter than it does during the summer.

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?

Re: The bottleneck might be the air in the room

#193

Post by bob1029 »

kashishgrover wrote: post #27

Oh this is absolutely so relevant and I wonder if there are any high quality studies that have analyzed driving performance against CO2 buildup in cars. Cars often ship with circulate air feature in the aircon, and people use it aggressively, nonchalantly at least where I live, having no idea about the dangers of possible hypoxia and sleepiness that might be inducing in them while driving. It is absolutely critical i…

[dead]

Re: The bottleneck might be the air in the room

#194

Post by doginasuit »

I find it kind of funny that we've been low-key suffocating the higher order function of our brains ever since we started building structures to live in with very little awareness of it. My mom is one of those people who complains that the air is getting stale and opens a window, the hero we needed.

Re: The bottleneck might be the air in the room

#195

Post by GuB-42 »

londons_explore wrote: post #139
microtonal wrote: post #115

Earlier quoted context omitted.

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 th…

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.

Based on numbers, O2 concentration is probably not a good indicator.

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.

Re: The bottleneck might be the air in the room

#196

Post by joenot443 »

stein1946 wrote: post #77
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

Depending on the state, newer buildings do have regulations on air ventilation and quality.

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.

Re: The bottleneck might be the air in the room

#197

Post by prodigycorp »

kashishgrover wrote: post #27

Oh this is absolutely so relevant and I wonder if there are any high quality studies that have analyzed driving performance against CO2 buildup in cars. Cars often ship with circulate air feature in the aircon, and people use it aggressively, nonchalantly at least where I live, having no idea about the dangers of possible hypoxia and sleepiness that might be inducing in them while driving. It is absolutely critical i…

Your comment actually has me convinced that this isn't an issue. I've been a recirculation dude for my entire life, I literally don't drive any other way.

Re: The bottleneck might be the air in the room

#198

Post by bluerooibos »

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.

Anecdotal, but I'm convinced it screws up sleep quality. 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.

I'm certain many people are sleeping in similar conditions without realising and ventilating their rooms properly or leaving the door open.

Re: The bottleneck might be the air in the room

#199

Post by rahimnathwani »

bluerooibos wrote: post #198
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.

Anecdotal, but I'm convinced it screws up sleep quality. 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. I'm certain many people are sleeping in similar conditions without realising and ventilating their rooms properly or leaving the door open.

And window.

Re: The bottleneck might be the air in the room

#200

Post by uxhacker »

spockz wrote: post #189
XorNot wrote: post #180

Earlier quoted context omitted.

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/

You hit it even easier when driving in a car with the internal circulation turned on to keep nasty fumes out.

In a car with Recirculation Mode on Levels routinely spike between 1,500 and 4,000 ppm within 20 to 30 minutes.

I wonder how many driving accidents can be saved by having a co2 monitor in the car.

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