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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

#181

Post by lelanthran »

noja wrote: post #145
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 don’t think we actually care about co2 levels. I think we use them as a proxy for o2 levels (same as our bodies do). So your idea would be great.

> I think we use them as a proxy for o2 levels (same as our bodies do).

Probably. ISTR that depriving a body of oxygen results in a different response than overloading the body on CO2. It's why if you completely displace all air in the room with CO2, people choke, panic, etc, but if you use Nitrogen, people just keel over dead without realising it.

Re: The bottleneck might be the air in the room

#182

Post by stonegray »

kingkawn wrote: post #165
microtonal wrote: post #115

Earlier 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…

Mesh with the other Apple/et al devices in the room to take multiple samples and aggregate the results for an overall picture of the ambient co2

Just waiting for the followup post on HN: How I sent CO2 warnings to my entire office using an ESP32

Re: The bottleneck might be the air in the room

#183

Post by vintermann »

noja wrote: post #145
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 don’t think we actually care about co2 levels. I think we use them as a proxy for o2 levels (same as our bodies do). So your idea would be great.

I'm pretty sure that in a room where we replaced nitrogen with co2, we would be dead even if O2 concentrations were the same. Something about partial pressure. I notice AI explanations agree with me (not going to copy and paste them).

Re: The bottleneck might be the air in the room

#184

Post by embedding-shape »

Gigachad wrote: post #147
embedding-shape wrote: post #132

Earlier 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…

> Thread is significantly better.

Better than what already exists and is deployed? I dunnno, hardware already in use always beat "hardware conceptually better but I don't have it", that's why Zigbee is better, for me. Protocols much like everything in the world, isn't correct/incorrect or universally "better", it's all down to use cases.

Personally, as someone who started to rely on IKEA providing Zigbee devices, Thread is obviously worse, because 100% of the devices I have are already Zigbee and not Thread.

Re: The bottleneck might be the air in the room

#185

Post by dgellow »

raffael_de wrote: post #135
ifwinterco wrote: post #89

Earlier quoted context omitted.

It's peak HN meme material because 1) it (allegedly) affects your intelligence which everyone here values highly 2) you can measure it, it's a number 3) requires tech to measure it So perfect for HN, you can obsess over numbers and tech and how to measure it endlessly and overhype the significance to trick yourself into thinking you're doing something useful. You get to have your cake and eat it, no wonder everyone l…

Also this is finally a great reason to order a dozen Arduinos + sensors for a domestic IoT project.

Sounds like a positive thing :)

Re: The bottleneck might be the air in the room

#186

Post by vertnerd »

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 monitor home, I found the levels there were elevated even with no one home and surpassed 2000 with just two or three of us in a room.

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.

Re: The bottleneck might be the air in the room

#187

Post by [deleted] »

noja wrote: post #145
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 don’t think we actually care about co2 levels. I think we use them as a proxy for o2 levels (same as our bodies do). So your idea would be great.

[deleted]

Re: The bottleneck might be the air in the room

#188

Post by Gigachad »

embedding-shape wrote: post #184
Gigachad wrote: post #147

Earlier quoted context omitted.

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…

> Thread is significantly better. Better than what already exists and is deployed? I dunnno, hardware already in use always beat "hardware conceptually better but I don't have it", that's why Zigbee is better, for me . Protocols much like everything in the world, isn't correct/incorrect or universally "better", it's all down to use cases. Personally, as someone who started to rely on IKEA providing Zigbee devices, Th…

Ikea preemptively sorted this out by putting thread radio in their hubs years before rolling this out. There's also thread radios in the latest chromecast, apple tv, and loads of other products. If you have a single thread border router in your house from any brand you'll be able to connect to any thread device from any brand. Phones can also directly control thread devices without needing any network or hub.

It's a vastly better system and the transition period is so smooth because the smart home companies have been deploying the thread hardware for years before anyone started using it.

Re: The bottleneck might be the air in the room

#189

Post by spockz »

XorNot wrote: post #180
noja wrote: post #145

Earlier quoted context omitted.

I don’t think we actually care about co2 levels. I think we use them as a proxy for o2 levels (same as our bodies do). So your idea would be great.

This is extremely wrong: CO2 impairment kicks in around 1000 ppm[1] possibly lower. You can hit this breathing by yourself in an unventilated 3x3m room (literally measured in my house). 1 https://pmc.ncbi.nlm.nih.gov/articles/PMC4892924/

You hit it even easier when driving in a car with the internal circulation turned on to keep nasty fumes out.

Re: The bottleneck might be the air in the room

#190

Post by dgellow »

eastbound wrote: post #93
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’ve lived in Australia and France and I’ve always attributed the taller size of Australians to the excellent state of their ventilation in buildings. Vents (and rooms themselves) are systematically bigger than in France, and if you live in a healthy environment, with meat, lots out outdoors during teen age, and correctly ventilated classrooms during their 20 best years, it makes no secret to me that they grew bigger…

> it makes no secret to me that they grew bigger

That sounds like something you made up to justify your beliefs…

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