Anecdotal, but I used to work in an IT department where some areas had good, or at least tolerable, ventilation and some very clearly did not. The difference in

Anecdotal, but I used to work in an IT department where some areas had good, or at least tolerable, ventilation and some very clearly did not. The difference in moods and productivity between teams in each was distinct enough to notice, but, at the time, I don't think anyone would have thought of CO2 levels as a confounding issue.