Developments in Wind Tunnel Studies for Estimating the Cross Ventilation Potential for a Low-Rise Building in a Built-Up Area

To accurately estimate the natural wind driven ventilation potential of a specific low rise building in a densely shielded or built-up area under local wind conditions, it is necessary to have site wind frequency data, pressure coefficient data, details about the windward and leeward openings of the building and the data related to building design. This paper summarises the appropriate data and discusses how to obtain these in order to estimate the natural cross ventilation potential of such a low-rise building. While building and weather information are relatively easy to obtain, a fundamental issue is the need to determine the wind pressure coefficient. Although published data are available, these are often not sufficient to satisfy the particular needs of individual building geometries exposed to specific surrounding shielding patterns. In these instances, wind tunnel analysis remains an important tool. However, small scale models are required in order to incorporate sufficient surrounding terrain. In the past, scaling has been hampered by the need to include an array of pressure taps on each face of the scale model. By using hook type surface mounted pressure taps, as outlined in this paper, it is possible to reduce scale size. This greatly improves the ability of wind tunnel models to simulate the local environment around buildings for cross-flow analysis. Such data also has application in more complex studies involving air quality and computational fluid dynamics analysis.