Evaluation of Indoor PM Distribution by CONTAM Airflow Model and Real Time Measuring: Model Description and Validation

Particulate Matter (PM10, PM2.5, and PM1) entry into hospital buildings is important for human exposure and is associated with health effects. The present study investigated the entry of particles into Imam Khomeini general hospital building under different ventilation systems and scenarios using a multi-zone airflow and contaminant transport model. Concentrations of PM10, PM2.5, PM1, and meteorological variables (atmospheric pressure, air temperature, and relative humidity) were measured and recorded in 6 medical treatment floors and outdoor atmosphere of hospital, from June 2014 to June 2015, 7 days at each season as simulation input variables. Simulated ventilation rates were assessed using the model and then validated using both measured data and simulations. In this study, CONTAM was used as a multi-zone indoor air quality and ventilation analysis software to determine airflows and contaminant concentrations. The simulation results for PM2.5 concentration as an important contaminant in hospital floors from basement to the top and based on airflow design were 21.3, 16.5, 22, 25.4, 27.6, and 24.2 μg/m3 respectively which showed 8.1% average deviation with actual measurements in selected locations. The assessment of air ventilation effect on PM2.5 concentration proved more accumulation in winter. The study results showed that accurate particle deposition and penetration are effective in predicting the time-varying particle concentrations in all floors of hospital building. The comparison between measurements and CONTAM prediction suggests that a multi-zone particle transport model can provide insight into particle entry into the hospital building under various weather and building operating scenarios.