Kinetics of gaseous indoor air pollutants: integrated analysis of air exchange, decay, and emission rates

To estimate indoor pollutant concentrations, this study investigated factors influencing indoor air quality using established tools and models. Key parameters, including infiltration rates in various buildings, were analysed. Findings showed an average infiltration rate of 0.302 ± 0.171 h-1 in tropical buildings, with central air conditioning systems yielding lower rates compared to split-type units due to differences in surface-to-volume ratios. Formaldehyde from paint was the focus, with a decay rate constant of 0.254 ± 0.057 h-1 at 25°C from laboratory experiments. Emission rates of formaldehyde from commercial paints were analysed using mass conservation, with profiles explained by the log-normal distribution equation. Cumulative formaldehyde mass discharged during laboratory tests ranged from 2 mg/m2 to 13 mg/m2. Full-scale experiments validated air exchange, decay, and emission rates using chemical mass balance equations and CFD software, showing a strong correlation and confirming the model's accuracy in evaluating indoor pollutants.