Since SnappySense uses eCO2 ("equivalent co2") as its CO2 measurement I thought I might investigate. There's a pretty good description of eCO2 here: https://electronics360.globalspec.com/article/17986/what-are-eco2-sensors, suggesting that if you have a sensible TVOC sensor then an eCO2 "sensor" (really it's just a calculation based on TVOC) will get you directionality of CO2 concentration (it's getting better or worse) but not anything that is a reliable CO2 measurement. Good CO2 detectors are apparently elaborate and expensive.
In practice therefore, SnappySense could perform eCO2 readings but should label them as eCO2 and not CO2, and should probably have "increasing", "decreasing", and "stable" as the values displayed, in some way, not the ppm reading.
There was a HN thread on the subject of IKEAs new home environment monitoring device, https://news.ycombinator.com/item?id=34817391. In it there was a comment that "eco2 is basically useless", https://news.ycombinator.com/item?id=34819564, and a fair amount of other griping about CO2 sensors elsewhere in the discussion.
Since SnappySense uses eCO2 ("equivalent co2") as its CO2 measurement I thought I might investigate. There's a pretty good description of eCO2 here: https://electronics360.globalspec.com/article/17986/what-are-eco2-sensors, suggesting that if you have a sensible TVOC sensor then an eCO2 "sensor" (really it's just a calculation based on TVOC) will get you directionality of CO2 concentration (it's getting better or worse) but not anything that is a reliable CO2 measurement. Good CO2 detectors are apparently elaborate and expensive.
In practice therefore, SnappySense could perform eCO2 readings but should label them as eCO2 and not CO2, and should probably have "increasing", "decreasing", and "stable" as the values displayed, in some way, not the ppm reading.