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Comment by brilee | Hacker News Reader

No. I wrote up the computations explaining why. See http://www.moderndescartes.com/essays/co2_closed_rooms/

If you prove that, in theory, the results you observe shouldn't occur this usually means you're using the wrong theory. In your case you're not looking at the differential binding of oxygen and carbon dioxide to hemoglobin.

This research in 2017 and the many studies it references on page 4 beg to differ with you: https://www.researchgate.net/publication/311844520_Carbon_di...

> At 5 millibars (5,000 ppm), you would start breathing at a 10% elevated rate, which you probably wouldn’t notice.

Wouldn't you? Won't you subconsciously notice and want to end the meeting faster?

Imagine breathing at an elevated rate in a crowded room that lacks proper ventilation. There's more than co2 coming from the human body. People will begin sweating, farting, etc., and fill the air with all kinds of pollutants. The computers, screens, dry erase board, etc. will make the situation even worst.

I know that such a room will make me want to make quick decisions to leave quickly.

>Imagine breathing at an elevated rate in a crowded room that lacks proper ventilation. There's more than co2 coming from the human body. People will begin sweating, farting, etc., and fill the air with all kinds of pollutants. The computers, screens, dry erase board, etc. will make the situation even worst.

Your description makes me think of the opening scene from Falling Down.[0]

[0]https://www.youtube.com/watch?v=piPzExBdfIg

You're referring to a psychological effect, he's referring to an autonomic. It's the same way the you don't tend to notice your heart rate increase and decrease as you move around unless it's major.

The opening post was about a psychological effect to which this poster responded "No. I wrote up the computations explaining why." and linked to a paper which had as a conclusion an increase in breathing rates.

My point is that a crowded room likely has more than one causes which could explain why productivity is lowered and decisions making worsened.

You won't notice an autonomic response but your brain likely will and it might very well answer by releasing adrenaline, cortisol, etc., and make you more anxious and stressed to encourage you to leave the environment that is causing the increased breathing rates.

....did you actually test if breathing rate changes? If not, on what basis can you say you're correct?

It is known in physiology that respiration rate is more or less determined by concentration of CO2 in the blood. Probably doesn't need to be independently tested.

You’d still want to test. And if it was increased, the next thing to test would be whether a 10% increase in baseline respiratory rate was benign. It’s not obvious that it would be, since breath is so tightly regulated.

OP spoke with rather more certainty than warranted.

Is one person, or two in a closed room overnight the same, or similar to a conference room with say, 15-20 people for several hours? My apologies if you addressed this.

Not sure what CO2 levels that would generate - you'd need to measure to be sure. But my calculations suggest that effects are negligible even up to ~5000 ppm, and many of these studies are boohooing about 1-2000ppm conditions.

I do think this area is understudied. It's just that being afraid of the air supply is such an easy way to nocebo yourself.

I have a pedantic correction.

The lowest number this article talks about being bad is 945ppm. A ppm of 600 is discussed as "fairly low" co2 levels. They are clearly not boohooing over the entire range of 1-2000.

So, you conclude that breathing faster is the only effect of increased environmental CO2?

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