3 ms·

This is advice that gets thrown around a lot, but it's missing the important bit of how to buy a meter that's both reasonably accurate and affordable. There are

This is advice that gets thrown around a lot, but it's missing the important bit of how to buy a meter that's both reasonably accurate and affordable. There are countless articles online showing how widely commonly sold meters vary in their readings. What's more, paying more often does not mean you'll get a more accurate reading. Sure, there's diminish returns and past a certain point it doesn't matter, but many meters are completely unreliable.

crazygringo 1y ago
The Awair Element is the best option for consumers who want something easy and relatively inexpensive. Hackers may prefer other options.
- entropie 1y ago
  Awair is awesome and very sensitive but pretty expensive (150€ for mine) but integrates well in HA
Night_Thastus 1y ago
The problem is there are a lot of effectively 'fake' CO2 monitors. They can't monitor CO2, they only monitor something else and work backwards to estimate CO2 levels. The cheapest real ones I've found are on the order of ~$150
- buckle8017 1y ago
  Unless your CO2 monitor has purge gas to calibrate it's going to underestimate indoor CO2. They all assume that they will be exposed to atmospheric concentrations of CO2 at least once a week.
  - imp0cat 1y ago
    In their defense, they usually mention this requirement in the manual.
    - buckle8017 1y ago
      Sure but do you take your CO2 meter for a walk?
      - Etheryte 1y ago
        And in similar vein, when was the last time you read the manual for a household appliance?
        imp0cat 1y ago
        Both fair points. I like to familiarize myself with any appliance I buy, so I tend to read the manual at least once. And yes, it's usually a waste of time. :)
      - crazygringo 1y ago
        When nobody is home so there's no CO2 being emitted, it goes down to outdoor levels within a couple of hours if your windows are open even a crack. If you have a meter that shows you a graph on your phone, you can watch it reach equilibrium. It's very obvious.
jrmg 1y ago
I tried to do this (buy an affordable priced, reasonably accurate meter) and, after probably after reading the same articles as you, reached the conclusion that there are no meters that are accurate and affordable. So many seem to rely on automatic ‘calibration’ - which just seems to consist of “let’s assume the lowest sensor readings of the last while correlate to baseline atmospheric CO2”. For a meter that’s never taken outside, this is obviously going to mean it’s reading too low all the time after a few ‘calibration’ cycles. And, worse, it's likely to be more wrong in less well ventilated spaces.
ludicrousdispla 1y ago
I have an "INKBIRD WiFi Indoor Air Quality Monitor" (INK-CO2W) and consider it useful and reliable for my purposes. You calibrate it by setting it outside for a bit to establish the baseline and then bring it inside. The detected CO2 level noticeably tracks with the number of people in the living room in which it is located and whether outside air is being pulled in, either due to the furnace or having multiple windows open. We do not use the app, so I can't comment on that. And my only complaint is that it has to be plugged in otherwise it runs out of power in an hour or two.

crazygringo 1y ago

The Awair Element is the best option for consumers who want something easy and relatively inexpensive. Hackers may prefer other options.

entropie 1y ago
Awair is awesome and very sensitive but pretty expensive (150€ for mine) but integrates well in HA

Night_Thastus 1y ago

The problem is there are a lot of effectively 'fake' CO2 monitors. They can't monitor CO2, they only monitor something else and work backwards to estimate CO2 levels. The cheapest real ones I've found are on the order of ~$150

buckle8017 1y ago
Unless your CO2 monitor has purge gas to calibrate it's going to underestimate indoor CO2. They all assume that they will be exposed to atmospheric concentrations of CO2 at least once a week.
- imp0cat 1y ago
  In their defense, they usually mention this requirement in the manual.
  - buckle8017 1y ago
    Sure but do you take your CO2 meter for a walk?
    - Etheryte 1y ago
      And in similar vein, when was the last time you read the manual for a household appliance?
      - imp0cat 1y ago
        Both fair points. I like to familiarize myself with any appliance I buy, so I tend to read the manual at least once. And yes, it's usually a waste of time. :)
    - crazygringo 1y ago
      When nobody is home so there's no CO2 being emitted, it goes down to outdoor levels within a couple of hours if your windows are open even a crack. If you have a meter that shows you a graph on your phone, you can watch it reach equilibrium. It's very obvious.

jrmg 1y ago

I tried to do this (buy an affordable priced, reasonably accurate meter) and, after probably after reading the same articles as you, reached the conclusion that there are no meters that are accurate and affordable. So many seem to rely on automatic ‘calibration’ - which just seems to consist of “let’s assume the lowest sensor readings of the last while correlate to baseline atmospheric CO2”. For a meter that’s never taken outside, this is obviously going to mean it’s reading too low all the time after a few ‘calibration’ cycles. And, worse, it's likely to be more wrong in less well ventilated spaces.

ludicrousdispla 1y ago

I have an "INKBIRD WiFi Indoor Air Quality Monitor" (INK-CO2W) and consider it useful and reliable for my purposes. You calibrate it by setting it outside for a bit to establish the baseline and then bring it inside. The detected CO2 level noticeably tracks with the number of people in the living room in which it is located and whether outside air is being pulled in, either due to the furnace or having multiple windows open. We do not use the app, so I can't comment on that. And my only complaint is that it has to be plugged in otherwise it runs out of power in an hour or two.