A new approach on zonal modeling of indoor environment with mechanical ventilation

This paper reports the development of a new zoning approach based on room air age, a parameter that indicates the mixing condition of the air. Zoning criteria are developed based on the deviation ratio of air age as well as location of the key source that is of concern (e.g., temperature, air pollutant). By integrating the zonal model with other models such as dynamic models for heat and moisture transfer, and source/sink models for air pollutant, the dynamic characteristics of indoor parameters such as air temperature, humidity, and pollutant concentrations can be simulated. A case study was presented for a displacement ventilated room, and simulation results using the new zonal model were compared with those using a computational fluid dynamics (CFD) model and a conventional zonal model. Results demonstrated that the new zonal model is more accurate in calculating the zonal temperature distributions than the conventional zonal model. The model is suitable for dynamic simulations (e.g., whole year) of indoor environmental parameters.