Wind velocity effects on the quality and efficiency of ventilation in the modelling of outdoor spaces. Case studies

Outdoor spaces are air volumes between buildings that are open to atmospheric air. Surrounding buildings hinder and alter airflow, which affect the exchange process and its quality. Given that this outdoor air is captured to ventilate a building’s interior, the geometric characteristics and wind exposure of these outdoor spaces are vital to optimising these processes. One of the parameters under study is the variable wind speed. The goal of this article is to ascertain whether different wind velocities affect airflow patterns in these spaces. To this end, eight archetypal shape/volumetric cases of urban buildings are examined from an air exchange efficiency perspective. Practical application: The result is described by a mathematical expression that links the exchange efficiency with a range of wind velocities (0.75–6.00 m/s), which confirmed that this wind velocity range implies variations of only ±1.0% in interior courtyards, ±1.6% in adjacent exterior spaces between buildings, and ±2.4% in the considered control volume.