Wind-Driven Cross-Ventilation Modeling of a Low-Rise Residential Building in an Isolated and Surrounded Suburban Environment

Natural ventilation is an essential element of sustainable buildings design as it can improve occupant thermal comfort and indoor air quality without the use of mechanical systems. The current study investigates wind-driven cross-ventilation across a low-rise residential building with complex geometry and internal partitions consistent with typical constructions. High-resolution computational fluid dynamics simulations are conducted using a three-dimensional steady Reynolds-averaged Navier–Stokes approach with a realizable two-layer k–ε turbulence closure model. Various wind speeds and directions are simulated for different types of partitioning and window configurations. Additionally, cases with surrounding buildings consistent with Canadian suburban neighborhoods are compared to isolated building cases. The results indicate that partition walls block the airflow, which creates dead zones. Openings introduced on partition walls, forming a network of openings, only slightly changes the number of air changes per hour (ACH) but significantly reduces the local mean age of air (MAA). This leads to significantly improved ventilation in rooms that previously only had a doorway opening. Furthermore, the presence of surrounding buildings should not be neglected when analyzing ventilation performance. For the surrounded study case, ACH can be reduced by more than half leading to a significant increase on the MAA (up to 215%) for the entire building. These findings highlight the importance of modeling both internal partition and external microclimate in natural ventilation designs to achieve a high ventilation performance in residential buildings.