Understanding the behaviour of aerosols in the indoor environment is important in a number of areas. Aerosol deposition affects the exposure to pollutant and allergenic aerosols as well as pathogenic biological aerosols and radiological aerosols. The ability to estimate deposition and aerosol dispersion can be used to assess the risks from such aerosols.

Many approaches have been taken for predicting aerosol dispersion and deposition in indoor environments. One such approach is the relatively recent semi-empirical three-layer model proposed by Lai and Nazaroff (2000). This model includes the effects of turbulent and Brownian diffusion and gravitational settling. Aerosol deposition and dispersion is obviously dependent on the air flow within an enclosure and the three-layer model had been combined with computational fluid dynamics modelling in the form of a drift-flux model by Chen et al. (2006), based on the formulation described in Chen and Lai (2004). This approach has the potential to calculate aerosol deposition for specific indoor flow configurations with moderate computational cost.

The aim of this work has been to test the suitability of this modelling approach for predicting aerosol behaviour in indoor environments by comparing its performance against aerosol ventilation measurements reported in the literature.  To carry out an accurate comparison, it is necessary to use a dataset for which there is a carefully defined room geometry and airflow. To meet that requirement, a study of a simple ventilated room as reported by Bouilly et al. (2005) with a single inlet and outlet in a number of configurations was used.