The natural ventilation in tall buildings is significantly different from that in low-rise buildings. It is imperative to record the wind available on site as a prerequisite for designing wind-driven natural ventilation. This paper aims to establish the significance of collecting site-based wind data and highlights the gap between the observed wind speed and the one used in practice.
The method consists of experimental study to determine the available wind speed for a 100-metre-high building in a warm and humid climate. The analytical mathematical model that uses the interpolation method based on secondary wind data was used to equate wind velocity at such heights. The study compares both methods to understand the gap in predicting the vertical wind profile.
The existing practice of using a wind rose and predictive mathematical model needs to be confirmed with site-based wind data before being used as an input parameter for designing for natural ventilation on upper floors.
Further studies can be undertaken to establish the variation of wind speed at the midriff of the building, derive an average rate of decrease in wind velocity and give a generalised wind input as a design guideline. A correction factor for the change in wind velocity can be helpful in determining the wind profile in the vertical component closest to the real-time data. The study is limited to outdoor wind velocity at various heights encountered at the windward side of the building. The study is region-specific.
The practice by designers and architects to use wind rose, composed of wind data available at 10-metre height, to design for naturally ventilated high-rise buildings is redundant. The study shows that the wind velocity profile changes beyond 20 metres. The prospect of a sustainable high-rise project is dependent on efficient natural ventilation, and hence the input wind velocity cannot be generic.
