Measurement and prediction model of CO2 concentration in ventilation conditions

Taking CO₂ generated from dry ice and human breath as the tracer gas, measures changing patterns of the CO₂ concentration for different air changes and establishes the prediction model of indoor CO₂ concentration. Wherefrom obtains the relationship of the CO₂ concentration difference between indoor and outdoor and air changes when occupants are in a normal working state and there exists air infiltration through the gaps of doors and windows, by which the minimal air changes can be obtained. The experimental results show that when considering the air infiltration, the concentration decays exponentially in a non-occupied room, and the minimal fresh air volume is 35 m³ per person per hour for meeting the requirements of indoor air quality and energy saving.