Carbon dioxide (CO2) is a gaseous component of the earth’s atmosphere. The concentration of CO2 in natural ambient air is about 0.04% or 400ppm. With each breath, humans convert oxygen (O2) into carbon dioxide.
Although carbon dioxide is invisible and odorless, an increased CO2-content makes is apparent because humans will notice increased fatigue and reduced concentration. In rooms with high occupancy such as conference rooms and theatres, negative effects become all the more evident.
Modern climate control can assure optimal air quality by adjusting the supply of fresh air based on the measurement of CO2 concentration in the indoor air. The CO2-concentration is regarded as an important measure of indoor air quality.