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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

#261

Post by avhception »

wouldbecouldbe wrote: post #254
throw0101a wrote: post #217

Earlier quoted context omitted.

> 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…

I think modern domestic houses its the opposite. At least in Netherlands insulation is such a strong focus, due to climate change I think, that modern appartments have terrible ventilation

A friend of mine recently moved to a modern apartment, built only a few years ago to a very high isolation standard (Germany). I stayed over night and slept on his couch, the air got really really dry and stuffy. It was really uncomfortable.

Re: The bottleneck might be the air in the room

#263

Post by hydevito »

wouldbecouldbe wrote: post #254
throw0101a wrote: post #217

Earlier quoted context omitted.

> 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…

I think modern domestic houses its the opposite. At least in Netherlands insulation is such a strong focus, due to climate change I think, that modern appartments have terrible ventilation

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 only ~2 inches due to the "efficient" design.

Re: The bottleneck might be the air in the room

#264

Post by irdc »

londons_explore wrote: post #141

Are there studies which analyze performance Vs artificial CO2? Natural CO2 in a room probably correlates strongly with other things given off by humans... Farts, water vapour, viruses, etc. The effect needs to be properly understood before totally redesigning the nations ventilation systems on a possibly wrong premise.

There are. The article literally cites a publication describing just such a study.

Re: The bottleneck might be the air in the room

#265

Post by alienbaby »

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…

Is it a tually lower oxygen in the blood that's the problem, or higher co2? I'm not sure if having high co2 automatically implies lower oxygen, I have no idea at all but feels like it may not necessarily be strictly. Linked. Also, are the cognitive issues of low oxygen the same as high co2 or do they produce different effects?

Re: The bottleneck might be the air in the room

#266

Post by OptionOfT »

wouldbecouldbe wrote: post #254
throw0101a wrote: post #217

Earlier quoted context omitted.

> 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…

I think modern domestic houses its the opposite. At least in Netherlands insulation is such a strong focus, due to climate change I think, that modern appartments have terrible ventilation

How modern? We built or house in Belgium in 2016, and it was completely sealed, very well insulated, but the air quality was good because we had mechanical ventilation. Clean air blown in, stale air extracted which then went through a heat exchanger.

The only issue this house had was it overheated. We had glass facing south. Even in winter it instantly became too hot.

Re: The bottleneck might be the air in the room

#267

Post by dev1ycan »

Tossrock wrote: post #12

Submarines operate in the 1000s of PPM CO2 range and the sailors aboard generally do not experience any ill effects. This was tested and no deficits were found even at 15,000 PPM: https://asma.kglmeridian.com/view/journals/amhp/89/6/article...

Submarineers also are hand picked due to their great lung capacity...

Re: The bottleneck might be the air in the room

#268

Post by pieterhg »

hydevito wrote: post #263
wouldbecouldbe wrote: post #254

Earlier quoted context omitted.

I think modern domestic houses its the opposite. At least in Netherlands insulation is such a strong focus, due to climate change I think, that modern appartments have terrible ventilation

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.

Re: The bottleneck might be the air in the room

#269

Post by kryogen1c »

GuB-42 wrote: post #195
londons_explore wrote: post #139

Earlier quoted context omitted.

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, 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 faulty reasoning that could lead to incorrect results in the future.

[1] https://societymechanicalventilation.org/wp-content/uploads/...

Re: The bottleneck might be the air in the room

#270

Post by II2II »

throw0101a wrote: post #217
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…

> 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…

Building codes that address this are wonderful, however:

- Plenty of people live or work in older buildings, where are not up to standard. For example: my office probably violates the air quality sensibilities of the Victorian era, which is when it was originally built.

- Equipment breaks down, isn't operated properly, or wasn't installed correctly. Having monitors that measure air quality is an extra check. While you may not be able to get direct action upon a consumer sensor, it can help you push for action.

I've been in buildings of varying quality over the years. I've seen how it takes time to get people in to do air quality testing. Heck, I saw the government claim that the air quality was acceptable in schools during the pandemic because the schools had passive ventilation systems. That meant they could open windows. (To be fair, the air quality in most of those buildings was probably fine since that was how the buildings were designed. That said, such standards make it easy for some buildings to slip through the cracks.)

So yeah, sensors to the people!

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