

CO2 concentration is an indicator of indoor air quality and can generally inform the quality of ventilation. Indoor plants likely won’t exchange enough to be effective.
Baseline (outdoor) is around 400 ppm, 1000 ppm is generally the ‘comfort limit’ or where some cognitive effects start to become present (drowsiness), then over 2000 ppm is generally the unhealthy limit.
Never thought I’d see an MMM article on here, but it’s definitely relevant.