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The bottleneck might be the air in the room
291–300 of 499 posts
Re: The bottleneck might be the air in the room
#292I can feel the AI in the text.
Yeah, I noticed it at "Here is the uncomfortable part. 1,000 ppm is not an extreme number."
Either AI, or LinkedIn brainrot.
Re: The bottleneck might be the air in the room
#293Earlier 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.
I had a project miniaturizing nasa tech for detecting hypoxia with o2 and CO2 sensors. It used a phosphorescent dye that changed a delay flash (ie you blinked a light, the dye would absorbed and blink back after a delay) based on temp and o2.
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!
Re: The bottleneck might be the air in the room
#294Earlier quoted context omitted.
Nope. Opening windows is very often disallowed - whether socially, or you'd need a hammer, or the space doesn't have windows. Or opening windows would have other downsides - letting in rain, or too-hot/too-cold air, or pollution, or ...
Can't let those stupid workers open a window and ruin the efficacy of the precisely engineered hvac system that lets the building hit LEED Platinum or whatever
Yeah. But even when you can, how many bosses might forbid it - because there's already too many arguments over the thermostats, or it's kinda noisy outside, or HR warned 'em of lawsuits for doing that when the air pollution numbers are elevated, or whatever?
Re: The bottleneck might be the air in the room
#295I 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…
> There are so many rooms, classrooms, movie theaters and other places with poor ventilation where you just feel dizzy, or fall asleep, not knowing it was just due to lower oxygen levels in your blood. Raising awareness is the only real solution. Not wrong, but it is perhaps worth noting that there are already standards for proper ventilation. Generally you're looking at 5–10 cfm/person (2.5-5 L/s), depending on the…
Should…
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.
Re: The bottleneck might be the air in the room
#296Earlier 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.
"Generally" is a vibe measurement to begin with. You won't notice any difference at all between 700ppm and 1000ppm. It's once you start hitting 2000ppm you are getting noticeable brain fog.
Had bad ventilation in my old apartment (built 1888) so got a co2 monitor. Started feeling the effect at 1100-1300ppm, so would open it in home assistant and check, never below and never above really. During winter when it was -10 so couldn't keep the window open all the time.
Re: The bottleneck might be the air in the room
#297Earlier quoted context omitted.
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, th…
>that's 0.2% CO2, it that CO2 is the result of respiration, it means that about 0.2% O2 was consumed, 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 f…
CO2 concentration doesn't start at zero, and by coincidence, if CO2 production is 80% of oxygen consumption, consuming 0.2% oxygen results in 0.16% CO2, add it to the base 0.04% and you get 0.2%.
Re: The bottleneck might be the air in the room
#298Earlier quoted context omitted.
> They recently overhauled their lineup and replaced all Zigbee devices by Thread + Matter. 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 cu…
Thread is significantly better. Zigbee relied on proprietary hubs and apps or hacky work arounds. Matter over thread devices don't need a brand specific hub or app. You can literally control the new ikea products direct from a modern iphone which includes a thread radio, no hub, server or app required. If you already own the ikea hub, they secretly put thread radio in it which was just sitting unused in preparation f…
This wasn't true for zigbee either. I used a zigbee usb stick with home assistant, could use any stick that was supported.
Re: The bottleneck might be the air in the room
#299I 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…
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Re: The bottleneck might be the air in the room
#300Earlier quoted context omitted.
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.
An open window means kilowatts of energy wasted. All the air I spent money cooling will just leak out.
It also means all the pollen will be let in.