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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

#311

Post by colechristensen »

quickthrowman wrote: post #307
josephg wrote: post #295

Earlier quoted context omitted.

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…

When was the last time you had that sensor calibrated properly with a can of test gas and a multimeter?

Take it outside, as long as it measures 400-450 it's probably good.

Metrology calibration is necessary if you want accuracy better than 10%, but most of us don't care at all about that, instead we care about increments of 200ppm or more.

Re: The bottleneck might be the air in the room

#312

Post by quickthrowman »

OutOfHere wrote: post #207
Gigachad wrote: post #151

Earlier quoted context omitted.

"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.

I disagree. I feel a very steady and progressive deterioration starting at 600 ppm. It becomes significant at 800 ppm. The studies back up the latter threshold.

You would not notice a difference if you weren’t checking the CO2 ppm. You primed your brain to ‘feel’ the effects of higher CO2 by reading a study and are experiencing the nocebo effect.

If it makes you feel better I don’t see a problem with it.

Re: The bottleneck might be the air in the room

#313

Post by throw0101a »

mort96 wrote: post #275
throw0101a wrote: post #229

Earlier quoted context omitted.

> The good news is that I stopped worrying about making my house "tight" for the sake of energy efficiency. I keep some windows cracked all year and don't worry about how tight the door seals are. The point of having "tight" houses is not (just) about energy efficiency but about air quality as well. The general mantra is build tight, ventilate right . It's why modern building codes mandate air tightness and having ER…

I would not want to live in a city where I have to be careful letting in outside air or going outside because there's too much air pollution...

> I would not want to live in a city where I have to be careful letting in outside air or going outside because there's too much air pollution...

1. Not living in a city (polluted or otherwise) still does not solve the problem of letting out cooled air and letting in hot-humid air in the summer, and letting out warmed air and letting in cold air in the winter. If your CO2 is high are you going to crack open a window when it's -10 outside? Or in the middle of a heat wave (esp. if you have AC and paid to run it to cool your house).

2. Not-city living also has pollen and other allergen leakage. You're also more likely to get wild fire particulates in less urban areas.

Building tight and ventilating right is applicable in all locations and all climates.

And in the extreme case, if you believe the outside is the healthiest environment, live in a tent or under a tarp. :) Buildings were invented to have a separate outside and inside, and leaky houses reduce the effectiveness of that separation.

Re: The bottleneck might be the air in the room

#314

Post by [deleted] »

Gigachad wrote: post #154
reddozen wrote: post #142

Earlier quoted context omitted.

CO2 and all other air quality indexers have to be very carefully calibrated regularly. It's not some slop you can just throw into a consoomer cheap iot device. Article author completely ignores this for the obvious reasons.

For the purposes of indoor ventilation monitoring you can calibrate by occasionally exposing the sensor to fresh air. Either taking it outside or just the room not having people in it. The sensor will treat the lowest reading it gets as 400ppm since this is what outdoor air is. A sensor mounted in the office will get calibrated every night when the office is empty.

[deleted]

Re: The bottleneck might be the air in the room

#315

Post by kibwen »

mort96 wrote: post #275
throw0101a wrote: post #229

Earlier quoted context omitted.

> The good news is that I stopped worrying about making my house "tight" for the sake of energy efficiency. I keep some windows cracked all year and don't worry about how tight the door seals are. The point of having "tight" houses is not (just) about energy efficiency but about air quality as well. The general mantra is build tight, ventilate right . It's why modern building codes mandate air tightness and having ER…

I would not want to live in a city where I have to be careful letting in outside air or going outside because there's too much air pollution...

Living in the countryside won't save you. I spent my childhood in a rural area and our house had the misfortune of being situated on a steep hill, so at all hours of the day and night you'd have cars and motorcycles and tractor trailers revving their engine to get up that hill. Every year we'd have to powerwash that road-facing side of the house to clean off the accumulated black grime, and sleeping with my window open, which faced that same road, always caused me to wake up raspy and hacking. Cars are a problem no matter where you live.

Re: The bottleneck might be the air in the room

#316

Post by jsnell »

salahadawi wrote: post #99
oasisbob wrote: post #23

There needs to be a meter for the amount of AI writing in blogposts. Same physics, same climb, same afternoon fog.

I've actually been tracking the front page of HN for AI posts for a while now: https://www.salahadawi.com/hacker-news-ai-detector This post evaluates to 99% AI generated.

Nice! Have you considered doing a Show HN for that?

That's valuable in at least three different ways: public education, showing that most of the articles are still human-written which can be easy to forget about sometimes, and as an easy way to cross-validate my intuition when flagging something as AI-generated without having to manually run Pangram.

I despair a little bit about how many HN voters either seem to want to read slop or don't understand when they're reading it. This post is obviously AI generated from the first paragraph on, and still has 480 votes.

Re: The bottleneck might be the air in the room

#317

Post by derefr »

roland35 wrote: post #293
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.

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…

> 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.

Can't you just measure CO2 "naively"; but then also, separately, measure rH; and then use the rH value to grab a research-calibrated LUT to pass the raw CO2 value through?

(I presume this is why all the little standalone CO2-sensor boxes you can buy also have rH displays. They're measuring it anyway to normalize the CO2 value, so they may as well make it a feature and display it.)

Re: The bottleneck might be the air in the room

#318

Post by losvedir »

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.

I agree it seems like a concern fad. I talked about it once with my brilliant MIT-educated 20 year Navy submariner brother-in-law and he didn't commit one way or the other but did say submarines have CO2 in the low thousands.

You'd think (hope) if there was a big effect here on performance, the relatively cheap/easy solution of maintaining lower CO2 would be standard. I know people think of the military as dumb grunts who you don't want to think, but he was one of the four department chiefs onboard (Weapons, Nav, I forget the others) and they have pretty substantial responsibility to make decisions on their own.

Re: The bottleneck might be the air in the room

#319

Post by joezydeco »

dgellow wrote: post #179
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.

Worst case people open windows without effect, no?

Opening windows can bring in pollen, dust, humidity, noise, and a lot of energy loss during cold winters and hot summers.

In a bedroom it might be worse than the elevated CO2 problem.

Re: The bottleneck might be the air in the room

#320

Post by salahadawi »

jsnell wrote: post #316
salahadawi wrote: post #99

Earlier quoted context omitted.

I've actually been tracking the front page of HN for AI posts for a while now: https://www.salahadawi.com/hacker-news-ai-detector This post evaluates to 99% AI generated.

Nice! Have you considered doing a Show HN for that? That's valuable in at least three different ways: public education, showing that most of the articles are still human-written which can be easy to forget about sometimes, and as an easy way to cross-validate my intuition when flagging something as AI-generated without having to manually run Pangram. I despair a little bit about how many HN voters either seem to want…

I've thought about it, will probably fix a few things and then do it
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