Anecdotally, back in college the rooms had CO2 monitors on the walls and I started to notice that professors who closed the doors and let the reader climb as high as 2400ppm were much more difficult to pay attention to than ones who left the room ventilated, with the reader staying 500-800ppm.
Anecdotally, back in college the rooms had CO2 monitors on the walls and I started to notice that professors who closed the doors and let the reader climb as high as 2400ppm were much more difficult to pay attention to than ones who left the room ventilated, with the reader staying 500-800ppm.