Abstract
The use of natural ventilation for commercial buildings becomes ever attractive due to the potential for economic savings and increased occupant satisfaction. However, it has proven to be particularly challenging to predict the indoor air temperature and airflow distribution from natural ventilation in more complex building geometries such as those with an atrium. This study used the energy-simulation-coupled computational fluid dynamics (CFD) method to predict the indoor temperatures of a typical multi-story, open-floorplan office building with a central atrium. The prediction accuracy using CFD was slightly improved for the periods with extreme outdoor conditions, where large temperature disparities often occur between simulation and experiment. For the tested cases, adjustment of window opening sizes seems to have marginal impacts on the simulation results. This paper further explores the impacts of outdoor gas-phase pollutants on indoor air quality of such a naturally ventilated commercial building with an atrium. A few architectural features such as window blockers and double skin façade (DSF) designs were numerically investigated for their performance to lower the indoor pollution levels while still maintaining adequate building ventilation rates. The results reveal that the features affecting the wind patterns around and above the building have a strong influence on the contamination rates on each floor of the building. DSF can not only reduce indoor pollution levels but also reduce the ventilation rate. When a pollutant source is not close to the building, a conventional central atrium design is preferred for better ventilation rates.
