CO2 Monitor to let me know when I need to let some new air into my office. Mine is a TFA Dostmann 31.5009, but any model with an NDIR sensor should be fine, there are many choices around 70-150 EUR.
CO2 poisoning is very common. It leads to fatigue, headaches/migranes and concentration issues. Most people don't recognize it and try to cope with caffeine & pain killers.
I noticed that sitting in a tightly closed office surrounded by monitors , CO2 was being trapped around me . I started testing with blood oxygen monitor and could reliably predict low blood O2 based on the above symptoms.
tl;dr keep your door and/or windows open and use a fan to circulate air into your desk area. It's very easy to reach high CO2 concentrations in a small room when you are surrounded closely with monitors (flat surfaces)
It's important to note these two issues (high CO2 and low oxygen) only go together in the most extreme scenarios and CO2 can be impactful long before O2 levels noticeably decrease or start affecting your blood O2 levels. For CO2 to be extremely high and causing headaches, dizziness, and nausea it's around 0.1% to 0.2% (more often represented as 1,000 to 2,000 ppm due to the low typical concentration of ~420 ppm globally). On the other hand, air is 21% oxygen (by volume) and at 10x the difference above different (so 1%) less it's not even considered oxygen deficient yet.
While I'm writing the comment, it's important to note you will almost certainly notice high CO2 content but you very likely won't notice low O2 content. Think about inhaling a helium from the balloon tank. You know there is very little O2 in it at all, you can even hear how it changes your voice, but you can keep breathing more in and out until you pass out cold and not even "sense" the lack of O2 until seconds before you pass out you start feeling very lightheaded. On the other hand if you breathed in CO2 like that you'd immediately notice and feel awful. This is because the body doesn't detect how much O2 you're taking in it detects how much CO2 you're able to get rid of. All this is to say, if you have low blood O2 levels don't necessarily expect to be aware of it.
The third thing I'll mention, since it seems inevitably someone comes by and reads "CO2" and confuses it with CO (carbon monoxide), is CO and CO2 are different things with different ppm values and different outcomes. It seems inevitably in the conversations CO will kill you in less than an hour at 1000 ppm, with effects from long term exposure possible at far less than that. If you have an appliance that burns fuel to function you really should have CO detectors, even if your state doesn't mandate one. If you don't get a CO2 monitor the worst that'll happen to you is you'll not feel as great (assuming CO2 isn't so bad your problem is actually there isn't enough oxygen left).
I just noticed this got pretty chopped up saving between a couple edits so here is a cleaner version if anyone needs it:
It's important to note these two issues (high CO2 and low oxygen) only go together in the most extreme scenarios. CO2 can be impactful long before O2 levels noticeably decrease or start affecting your blood O2 levels. For CO2 to be extremely high (causing headaches, dizziness, and nausea) it only needs to be in concentrations around 0.1% to 0.2%, more often represented as 1,000 to 2,000 ppm due to the low typical concentration of ~420 ppm globally. On the other hand, air is 21% oxygen (by volume) and at 10x the difference of 1%/10,000 ppm less than normal the air is not even considered oxygen deficient yet.
While I'm writing this comment, it's important to note you will almost certainly notice high CO2 content in your environment but you very likely won't notice low O2 content until it's well too late. Think about inhaling a helium from the balloon tank. You know there is very little O2 in it at all, you can even hear how it changes your voice due to the displacement, but you can keep breathing more in and out until you pass out cold and not even "sense" the lack of O2 until seconds before that moment when you feel lightheaded or your vision starts to fade. On the other hand if you breathed in CO2 like that you'd immediately notice and feel absolutely awful. This is because the body doesn't detect how much O2 you're taking in it detects how much CO2 you're able to get rid of. All this is to say, if you have low blood O2 levels don't necessarily expect to be aware of it.
The third thing I'll mention, since it seems to inevitably come up, is "CO2" (carbon dioxide) should not be confused with "CO" (carbon monoxide). CO and CO2 are very different things with different ppm values of concern and different outcomes when they are out of range. CO will kill you in less than an hour at 1000 ppm with effects from long term exposure possible at far less than that. If you have an appliance that burns fuel to function you really should have CO detectors, even if your state/goverment doesn't mandate one. If you don't get a CO2 monitor the worst that'll happen to you is you'll not feel as great (assuming CO2 isn't so bad your problem is actually there isn't enough oxygen left).
Keeping door and windows open while it's very cold or very hot outside can lead to extremely high heating/air conditioning bills. Meanwhile, high quality energy recovery ventilators that can exchange air with the outside without ruining your insulation tend to be a lot more than $200.
My home has very poor ventilation so I periodically will open the windows and blast a box fan to "flush" the dirty air out. If done quickly, there's not much thermal loss.
Although a bit above $200, but I own an Aranet4 CO2 monitor (it also measures humidity, air pressure, and temperature). It has a great app that allows you to see historical data too.
I've been using it for a while already and I'm really happy with it.
I've been wanting to get a CO2 sensor for a while now, but I want one that interfaces with Homebridge or directly with Homekit. I'd appreciate any recommendations!
