Cross-ventilation of a room in a courtyard building

•For courtyard buildings with an opening on the leeward side: Cross-ventilation rates increase with increasing courtyard building height.•Cross-ventilation is not sensitive to courtyard building height in an urban zone.•Opening Re numbers of courtyard buildings in a dense urban zone are very small. The influence of courtyard height on the cross-ventilation of a room abating a courtyard building is addressed in this work. While the cross-ventilation performance of isolated buildings has been thoroughly documented in the literature, the phenomenon is still not tackled in the context of a courtyard building, both in isolated as well as urban conditions. This has important implications on the design of such buildings (both new and retrofitted). A numerical approach using Computational Fluid Dynamics (CFD) is used to address these challenges. A courtyard model is first validated in 2D and 3D, using various turbulence models with existing data in order to determine whether a 3D approach is necessary for this study. Three generic buildings having different heights with a room located on the leeward side are then tested. This is performed for an isolated building and an urban scenario. Results show that there is an increase in the ventilation flow rate with increasing building height. Moreover, this flow is directed from outside the building and into the courtyard. This result has been confirmed for all scenarios tested. The consideration of rooms located in positions other than the leeward side of the building is left for future consideration.