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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.
Would be extremely cool if Apple, Samsung, and others can crack this, though I think they'd have done it already if it was easy.
The question is if oxygen levels are as good an indicator as CO2 levels... I suspect not.
(Upd: the IKEA does have lower accuracy, with ±100 ppm instead of ±30 ppm. From the SEN63C datasheet)
A price of 30 EUR makes this sensor really easy to pick up. For the same price as one Aranet (~180 EUR) the typical household can place a sensor in every room of the house. Which provides far more accurate readings for the whole house than just one high-end sensor in one room.
If you want a CO2 meter on the cheap, either wire up an optical NDIR sensor like the SenseAir S88 (22 Euro) up to an esp32, which is possibly the best sensor you can get for the money (slightly cheaper version of the sensor that the AraNet4 uses). Or if you want something standalone with a display, get the SwitchBot Meter Pro CO2 for ~50 Euro, which uses a photoacoustic NDIR, but is still miles better than the sensor in the ALPSTUGA. Can also be hooked up with HA through an ESPHome BLE proxy or with the SwitchBot Hub.
You can find a comparison of the IKEA sensor with other affordable sensors here:
https://danieldk.eu/hardware/smart-home/ikea-alpstuga
(Upd: the IKEA does have lower accuracy, with ±100 ppm instead of ±30 ppm. From the SEN63C datasheet)
You forget to mention that it is ±100ppm plus ±10% of the ambient ppm, which makes a big difference. At 1000ppm it's ±(100ppm + 0.10*1000) = 200ppm and that's only in an environment with 25C, 50% RH, and 1013 mbar. So, that does not tell you much, given that thermal conductivity is very sensitive to environmental factors.
I was shocked to see just how fast CO2 climbs while in a room, and how just opening the window just a crack was enough to restore the room to baseline co2.
The thing runs on usb 5v so the power consumption is negligible. It also plugs in to home assistant great.
It is a thermal conductivity sensor, which is a very indirect way of measuring CO2 and is very sensitive to environment factors. You only get somewhat good readings in lab conditions.
Don't by the ALPSTUGA for anything but very rough trends, there are much better affordable options.
There’s a huge leap from that to the power consumption being low enough to be integrated into a smartphone, as demanded by OP.
[1] https://ruuvi.com/air/
It can't be much, since the Aranet 4 can run for years on 2 AA batteries.
You'd have to raise awareness on every single person in the room and them sustain pressure to the organization in order to have proper CO2 levels in the room/organization.
And then you have to align every other person on every other organization to do this as well and hope for the best.
Or, you can do the right thing and have the state introduce regulations
But seriously, so much care needs to be taken here. OK, well "care" at least. Employers certainly would benefit from scrubbing CO2 from the air, in terms of productivity. I'm willing to bet that with central air it would be quite easy, and even with heat and AC off, lots of places still circulate the air regardless.
So the central place to scrub is already there.
But then you have other issues. Such as, will your body adapt to 8 hrs of reduced CO2, and then you become torpid and barely awake when not at work. Such a horrid thought, that is to me. And what if employers learn that the tiniest boost of O2 helps too! Now your body becomes accustomed to that, and what are the long term effects there?
I can personally envision myself being concerned. I guess the legislation could be crafted to "the same CO2 levels found just outside of downtown city core" or some such blather. Maybe even same for O2. So that you're at least pegged to something normal for the area.
Maybe that's where the state could come into play. A simple, highly accurate monitoring station which has an API to be polled.
Come to think of it, CO2 and O2 rates fluctuate during the 24 hour cycle. Trees need O2 to live, but only produce O2 during the day. And so differing amounts of light might mean up and downs in these numbers. It may be another circadian rhythm. Getting it the same as in a nearby forest, might be the healthiest thing of all.
The place to look is existing codes for ventilation. Exempli gratia: https://dos.ny.gov/system/files/documents/2020/09/2020-mcnys... (see PDF page 46). Regulations to enforce outside air being brought into human spaces already exist.
I have been in some office buildings in United States which had CO2 monitors in each meeting room, and the ventilation would engage to control CO2 below a set level. We would entertain ourselves by exhausting our lungs onto the sensors to trigger the ventilation system.
The main question is: If your workplace, city, whatever forces you to work or live in an harmful/unhealthy environment, do you have any realistic course of action to improve the situation? In the US you would call this (gasp) regulation, I would call it a basic human right.
If we talk about stairways, nobody complains about building regulations that mandate handrails. CO₂ levels are not totally different.
IIUC they also need fans. The one I have in my home has one that's actually integrated into the sensor unit.
Article author completely ignores this for the obvious reasons.
A sensor mounted in the office will get calibrated every night when the office is empty.
> Pulse oximeters have some limitations. They can only employ light at two wavelengths. Thus the devices can only distinguish between hemoglobin and oxygenated hemoglobin. When carboxyhemoglobin and methemoglobin are also present, there are two additional wavelengths required for differentiation. In the presence of elevated carboxyhemoglobin levels, pulse oximetry overestimates the true saturation of oxygen as carboxyhemoglobin binds with a higher affinity than oxygen. In the case of carbon monoxide poisoning, the absorbance spectrum of carbon monoxide is very similar to hemoglobin, which results in a falsely high level of oxygen (overestimation of oxygen saturation) ...
https://www.ncbi.nlm.nih.gov/books/NBK539754/
Why only 2?
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 problems.
Even if the watch could sample atmosphere directly, is it sensitive enough to detect a shift from 21.00% -> 20.79% oxygen?
As it's estimating oxygen in the owner's blood, it might not detect anything different at all... not if the owner's body has already compensated by breathing harder or by "underclocking" their brain to make dumber decisions.
[0] https://en.wikipedia.org/wiki/Asphyxiant_gas
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.
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.
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.
But also bear in mind that regardless of "are we operating at max effectiveness", OSHA sets a legal limit of 5000ppm in a workplace, and that's about _safety_.
This article is talking about keeping levels below 1000 which is a very high standard IMO (still arguably justified given the studies mentioned). But if you are in a poorly ventilated home office you could easily hit 3000. At that point you are closer to "illegal in the US" than "earth's atmosphere".
So yeah even if you are unconvinced about micro-optimising your CO2 levels there's a very long established argument in favour of at least paying _some_ attention to it.
The real problem is offices and meeting rooms where you have 10 people in a small box for hours and windows that don't open.
https://pmc.ncbi.nlm.nih.gov/articles/PMC4892924/
Meanwhile in France we heat classrooms by stacking 35 kids in a confined space. It saves on heating, plus condensation that makes windows opaque helps pupils concentrate on the blackboard, as teachers said during my childhood.
That sounds like something you made up to justify your beliefs…
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 loves this topic.
(Also if you're a doomer type you can link this in with rising atmospheric co2 levels for extra points)
Also go for a walk, unless you live in a hellhole.
So in practice the oxygen level can never drift meaningfully far from the atmospheric pressure, whereas carbon dioxide easily can because the pressures involved are so low.
But then why can we see problems with concentration in studies of people in poorly ventilated rooms, but not replicate that when just adding CO2 to normal air? What is the CO2 that we can measure in meeting rooms actually a proxy for?
I am suspicious of 0.1% having a significant effect though, given oxygen is around 20% and we naturally exhale a couple of percent CO2.
https://danieldk.eu/hardware/smart-home/esphome-senseair-s88
If you want something with a display that works on batteries without spending over 200 Euro for an AraNet, the SwitchBot Meter Pro CO2 is pretty good option. It is regularly on offer below 50 Euro. It uses photoacoustic NDIR, but does not deviate a lot from the S88. You can use it without a SwitchBot by configuring it with a phone on Bluetooth. The meter works on external power and battery, but even when on battery, you can set the reporting interval to 5 minutes, which is good enough in practice. The meter broadcasts the measurements with Bluetooth LE, so if you want to get the data in Home Assistant, you can place a ESPHome Bluetooth LE Proxy in the vicinity [1]. This is an ESP32 flashed with ESPHome that listens on Bluetooth LE advertisement and forwards them to your HA instance over WiFi. Of course, you could also get the SwitchBot Hub, but what is the fun in doing that? :)
I would avoid the Ikea ALPSTUGA, it uses a thermal conductivity sensor, which is a very indirect method for measurements and it's often several hundred ppm off.
https://esphome.io/components/bluetooth_proxy/
Looks like it's increased in price unfortunately but I like the idea, it's basically just what you would do as a DIY project but ready built. So you can either use it like a normal commercial product, or you can just fork the ESPHome config that's on GitHub and flash it exactly like any normal ESPHome project.
https://screek.io/ https://shop.screek.io/products/sco-b
No recommendation though, I haven't tried them.
Will look at adding the CO2 monitoring
Edit: actually, they only sell them as part of a 6-in-1 device, with a display, and a bunch of other sensors. That feels overkill, I wish they would just sell the CO2 sensor itself
The article talks about "within the hour". With four people in my living room doing normal things it jumps within 20min to around 1000ppm. If I am wrestling with my kids much sooner.
In offices companies often neglect it.
edit: if you are cooking on gas it also has an immediate effect on co2 of course apart from other small particles
Generally it’s a miracle to me so many people survive traffic on public roads, statistically.
This post evaluates to 99% AI generated.
IKEA now has a remarkably cheap ($35) air quality monitor that measures CO2 as well as PM:
https://www.ikea.com/us/en/p/alpstuga-air-quality-sensor-sma...
I don't have one yet but plan to pick one up soon. A CO2 sensor alone from Adafruit is $50+, though that one is more precise. I bought it a while ago and it's still sitting in my todo bin.
Flu and other air transmited diseases should be treated as a workplace injury, with proper compensation!
I want this implemented to fullest, preferably with full hazmat suit. Yet more reasons to support work from home.
The first needs to occasionally see new threats to stay up to date and healthy. The second will not like the constantly restricted airflow.
For instance, I'm now really only sure that author measured a 2000 ppm CO2 in a meeting room once. Everything else could just be LLM trying to invent convincing argument.
The worst thing is, I'm pretty sure humans are starting to mimic that cadence too...
Stoßlüften.
but then germany hasn't been doing so well lately, and people who do most of their work outside should also be doing better...
CO2 is just a tip as office or home is toxic environment anyway. Plastic (e.g. carpets), formaldehyde in furniture, air fresheners… add home office and cooking at home (-> small carcinogenic particles)…
If you start reading How not to die by Michael Greger, you find out that dust, soda and sitting - not CO2 - are real killers…
It's similar to how people think sharks and airplanes are the biggest killers - when in reality it is coconuts, mosquitoes, and motorcycles.
Dust is much more likely to just settle on the ground and be kicked back up than it is to move all the way to the purifier to get stuck in the filter.
https://en.wikipedia.org/wiki/Carbogen
I imagine it could easily be compensated by an equivalently minor increase of breathing rate or breathing depth.
[1] https://en.wikipedia.org/wiki/Gas_exchange#Alveolar_air
[2] https://en.wikipedia.org/wiki/Breathing#Composition
[3] 5/6 × 40000 ppm + 1/6 × 500 ppm = 33417 ppm; 5/6 × 40000 ppm + 1/6 × 5000 ppm = 34167 ppm; 34167 / 33417 = 1.0225
It's on my desk and I can confirm, opening the window if it gets orange helps a lot with thinking.
Some days in the morning it shows red and I barely can't think or get awake. Opening the window and it changes instantly.
After testing a variety of AQI sensors, I ended up acquiring multiple Airthings-branded devices.
They provided the best mix of CO2/VOCs/PM sensors in a single device with a decent enough app.
There may be better options now, but I have these at both home and office.
Highly recommend doing the research and learning about the environments you’re in, especially if you have little ones at home.
Edit to add: opening windows is usually the easiest/best solution!
Maybe it's not just the air but also the multi-hour meetings that drive people to a sense of "oh god let this finally end now", which leads do decisions that fall short.
Interestingly the Inkbird and the SCD4X quite often diverge by anything up to hundreds of PPMs; I kind of back the SCD4x (on a Pi in my case) for accuracy after lots of experimentation, reading the datasheet and ensuring the correct calibration procedurs are followed (basically expose the sensors to outside air once a week).
It's also interesting how much it varies day to day in my one-person office - possibly down to how windy it is outside, even with windows closed one day it never goes about 800ppm, other days it'll hit 1500ppm by lunchtime if I don't open a window.
N.B. Quite possible the Inkbird uses an SCD4x internally, seems reasonable kit so I have no explanation for the differences in readings.
https://www.ikea.com/au/en/p/alpstuga-air-quality-sensor-sma...
I once woke up with the fam in a hotel with airco at 5500 ppm. It is then that I learned the airco does not blow fresh air (logical after thinking about it).
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.
One of them seems to have much worse ventilation to the extent that it reaches double the level. Opening the window slightly 24/7 keeps it low.
My fiance's chronic headaches/migraines/idk became noticeably less frequent after this change and when they do occur it's usually because the window was accidentally left closed.
Anybody who struggles with this kind of thing might want to try checking their levels. Or just open a window I guess?
In most office buildings (towers) that's impossible. You have to deal with what the A/C gives you.
Why that matters? You need good ventilation regardless, but instead of just thinking of CO2, try to minimize compounds in your air by selecting things for the room that smell less and off-gas less.
https://science.nasa.gov/earth/explore/earth-indicators/carb...
Also, take walks. I am lucky to be able to walk to and from work and it helps immensely.
Support European!
https://aranet.com/en/home
Not to talk about the weather either.
A terrible way to make decisions.
Put it this way do you need to book a 3h meeting with your spouse to decide if to buy a house? Nope all the research and decision criteria were in advance. That final minute of making the decision is a cross check over that work.