Do you account for base CO2 level? Air in an unpopulated beach will be something like 420 ppm; and in my city the outside air is something like 600 ppm, so an e

Do you account for base CO2 level? Air in an unpopulated beach will be something like 420 ppm; and in my city the outside air is something like 600 ppm, so an empty well-ventilated room is still 680-ish ppm - so if someone starts exhaling, then you'd have to add the 720-864ppm of extra CO2 to that.