Ng E.
Year:
2008
Bibliographic info:
The International Journal of Ventilation, Vol. 6 N°4, March 2008

This paper addresses the process of optimising the benefits of the natural (air) environment in the case of a high density city in which the amount of building volume is ultimately constrained. It is hypothesised that, in densely built cities, the amount of vertically placed gaps, permeability and porosity of the cityscape will affect the ventilation and wind environment. Wind tunnel experiments are described in which different amounts and positions of gaps were applied to a simplified city layout. The air change potentials of buildings, an indicator of the air ventilation potential of the urban environment, as well as the air speed at pedestrian level were calculated. It can be established that a cityscape with more gaps will perform better. However it is also noted that the characteristics instead of the amount of gaps are more important parameters. Based on this investigation, a number of urban planning guidelines have been established for consideration by the Hong Kong Government.