301–310 of 499 posts
Comprehensive AIR monitor system is must to get most efficient output. Author is right here!
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…
Got a firsthand experience with this. I was dropping off my girlfriend and we stopped to talk in the car, with all the windows up. Over the course of the conversation we got more and more agitated at each other until I had a thought and pulled my Aranet out from my backpack. It was >3000ppm CO2. We opened windows and within 2 minutes all the agitation went away.
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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.
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The Satish 2012 study that seems to have started this trend was a small cohort of 22 people split in 6 smaller groups where they also just injected pure CO2 in a small room. There have been several attempts to reproduce, which sometimes found no clear effect, or a significantly smaller effect. This original study has been used to market these CO2 monitors for years, but the evidence is quite thin and doesn't support…
So is this all bullshit?
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…
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> 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 a…
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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…
> O2 sensor in cars compare the O2 concentration between the outside air and exhaust gases, it needs outside air as a reference 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.
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Got a firsthand experience with this. I was dropping off my girlfriend and we stopped to talk in the car, with all the windows up. Over the course of the conversation we got more and more agitated at each other until I had a thought and pulled my Aranet out from my backpack. It was >3000ppm CO2. We opened windows and within 2 minutes all the agitation went away.
Or, you became aware of the agitation and interrupted it. The CO2 was a placebo. You have invested already in the idea, it all clicked in your mind.
As a high school teacher, I first noticed this effect when I started using a CO2 monitor in my classroom as a proxy for air freshness during COVID. The CO2 levels in our supposedly "no problem with the air" classrooms shot up to 2000 ppm within minutes of the start of school and stayed there all day. Kids weren't checked out ONLY because I teach mathematics. They were breathing bad air, too. Worse, when I brought the…
Your comment is suspiciously missing the part where your students performed measurably better after decreasing CO2 concentration.