Optimal design of green buildings using computational fluid dynamics and climate simulation tools

Natural ventilation or self-ventilation is an economical way to improve indoor air quality. Climate factors such as temperature, received radiation, humidity, and wind flow can significantly affect natural ventilation of the buildings. This study aimed to investigate the performance of some commonly known strategies such as building orientation, aperture area, and coating color to promote natural ventilation on the hot and humid climate of southern Caspian Sea, north of Iran. These techniques are traditionally used without any specific knowledge on their individual importance and mutual effects. As an advanced modeling tool for energy assessment, Design-Builder was used along with computational fluid dynamics tab to numerically evaluate the results of each change. Among the many possible cases, seven scenarios were investigated by developing a comprehensive computer simulation model. The results show that thermal comfort can be increased up to 30% and suitable airflow can be achieved by increasing the space on the windward side, roof window on the leeward side, and employing light-colored coating for the rooftop. Applying these factors decreased the apparent temperature up to 10 °C in the summer design week.