Modeling particle fate in ventilation system—Part I: Model development

Aerosol particles are regarded as one of the most significant pollutants in the indoor environment. These particles can travel through ventilation systems, thus impacting indoor air pollution. Accurate modeling and prediction of aerosol particle transport in ventilation systems is therefore a key component of indoor particle pollution. Since recycled air takes particles into the ventilation system again, it can be challenging to calculate the particle concentration in each part of the system. This study theoretically and experimentally proves that the entire ventilation system, including filters, ventilation ducts and ventilation rooms, can be regarded as a serial of filters in steady-state cases. We call this the particle filter group model. Equations are presented to calculate the particle concentration in each component of normal kinds of mechanical ventilation systems. With this model, the particle concentration and deposited particle quantity in each part of the ventilation system can be easily calculated. This model may help to control indoor particle pollution and guide the cleaning of ventilation ducts and filters.