The effects of building form on the natural ventilation of commercial buildings.

Wind pressures can significantly affect ventilation performance. However often they are overlooked in the design of a naturally ventilated building, with buoyancy forces presumed to offer the worst case scenario for design. The result is that airflow patterns and the ventilation performance of the building is often different from the design intent. Successful natural ventilation design requires careful consideration of the building form, and so must involve the architect at the early stages of fabric development. Whilst devices and features may be used to enhance the performance of ventilation outlets, the wind flows at inlets are more likely to be affected by the form of the building, and less amenable to improvement by small devices. Performance may be improved by larger features that in effect become part of the building form itself. Therefore the designer requires a greater awareness of the effect of wind on natural ventilation. They may require access to targeted design information and design tools that are as yet generally unavailable.