Explaining the pattern of natural ventilation in central courtyards of traditional houses based on orientation

The city of Yazd contains numerous traditional houses designed in response to its hot and dry climate, where the central courtyard plays a key role in providing daylight, natural ventilation, and spatial organization. Despite their visual similarity, these courtyards differ substantially in form and orientation, and no specific guideline exists for enhancing airflow performance. This study examines the physical characteristics of central courtyards in Yazd’s traditional houses, with a primary focus on evaluating how courtyard orientation influences natural ventilation. A combined methodology was used, including empirical measurements, simulation analyses, and case studies of the Lariha and Golshan houses. While geometric dimensions and proportions of the courtyards are documented as part of their architectural typology, they were not treated as independent analytical variables in this research. The results show that courtyard orientation is the dominant parameter shaping airflow patterns, and in several simulated configurations, reorienting the courtyard increased wind speed by more than twofold. In contrast, very small variations observed in some orientations such as reductions on the order of 0.07 m/s were found to be negligible and not indicative of any meaningful decline in ventilation performance. Overall, the findings confirm that optimizing courtyard orientation can substantially enhance natural ventilation, while minor geometric differences play only a descriptive role and do not alter the study’s main conclusion regarding the primacy of orientation.