Atmospheric CO2

Indoor air quality is the chemical, physical and biological properties that indoor air must have to not cause any negative impact on occupants’ health and provide comfort: feel fresh, pleasant and stimulating. 

Amid the contaminant issues, air pollution has awakened more interest due to its potential health risk and its direct effect on human productivity. The overall indoor environment quality depends on the contribution of both the indoor and the outdoor air quality. The outdoor air pollutants penetrate indoor environments through mechanical and natural ventilation as well as by infiltrations through cracks and leaks in building’s envelope. The interaction between the indoor and outdoor air may be studied by the air exchange rate.

We propose a new approach for measuring air infiltration rates in buildings. The method belongs to the class of tracer gas techniques but, unlike conventional CO2 based methods that assume the outdoor ambient CO2 concentration is constant, the proposed method recognizes that photosynthesis and respiration cycle of plants and processes associated with fuel combustion produce daily, quasi-periodic, variations in the ambient CO2 concentrations.