> because CO2 levels can otherwise get unacceptably high overnight I got a CO2 sensor recently, and I'm surprised how much of a difference small changes can ma

> because CO2 levels can otherwise get unacceptably high overnight I got a CO2 sensor recently, and I'm surprised how much of a difference small changes can make. One of my rooms was hitting 1600-1800ppm overnight (which as I understand it is not a problem per se but not great) with the door open about 2in/5cm - leaving the internal door open an extra 6in/15cm or so means it rarely goes above about 700ppm (generally hovers around 600). I'm also surprised at how quickly it'll go up - that same room will go from 800ppm to 1600ppm with the door shut in well under an hour.