Comparing zonal and CFD model predictions of indoor airflows under mixed convection conditions to experimental data

The present work is part of a research effort aimed at integrating a detailed model of airflow in large spaces with an algebraic multizone infiltration model to describe pollutant transport and coupled air flows within and between complex buildings and large spaces. In the past 15 years, zonal models were developed with the goal to obtain an approximate prediction of airflow characteristics in large indoor spaces. Also, reducing the number of grids in CFD models is a natural way of decreasing their demand of computational resources to solve air flows in room. Therefore, we compare the ability of both zonal and coarse-grid k-e RANS models to predict air flows and temperature profiles in a two-dimensional building zone. Both predictions are compared with conventional k-e RANS models results and experimental data under mixed convection conditions. Our results suggest that zonal models constitute a suitable tool to assess thermal comfort in a room, and that coarse-grid k-e RANS is an appropriate method to quickly estimate details of airflows in a room.