CO2: 547 ppm
Temp: 18.10 C
<1000 ppm: Typical level for occupied spaces with good air exchange.
1000-1500 ppm: Start ventilation of the room.
1500-2000 ppm: Level associated with complaints of drowsiness and poor air. Ventilation recommended!
>1500 ppm: Level associated with headaches, sleepiness, and stagnant, stale, stuffy air. Ventilate!