Probability analysis of wind-driven natural ventilation potential in areaway-attached basements

Abstract

This article presents an exceedance probability analysis method to evaluate the natural ventilation potential in areaway-attached basements for residential purposes. This method can take the uncertainties associated with stochastic wind conditions into full account, and it uses the air change rate in the basement space as the evaluation index to calculate the exceedance probability distribution. A simple analysis approach is further proposed by extracting air change rates corresponding to the exceedance probabilities of 85% and 15% from the exceedance probability distribution curves. In order to determine the air change rate index for each wind direction accurately, a wind-tunnel experiment was performed on a two-story building scale model with an areaway-attached basement. A variety of parameters, including opening configuration, areaway plan area, building coverage ratio, orientation, and construction site of the model, were further investigated and analyzed in detail. The results demonstrate that the exceedance probability analysis is a useful tool for wind-driven natural ventilation potential analysis, and the findings of this article can provide quantitative information and guidelines for the design and application of areaway spaces.

Acknowledgments

This study is partially supported by a research grant from the Japan Society for the Promotion of Science (Project no. 09J09505) and partially by the Obayashi Foundation of Japan.

Zhen Bu, PhD, is Post-doctoral Researcher and Senior Building Physics Specialist. Shinsuke Kato, PhD, Fellow Member ASHRAE, is Professor.