A decision support tool for evaluating the air quality and wind comfort induced by different opening configurations for buildings in canyons

M Fan; C K Chau; E H W Chan; J Jia

doi:10.1016/j.scitotenv.2016.09.083

A decision support tool for evaluating the air quality and wind comfort induced by different opening configurations for buildings in canyons

Sci Total Environ. 2017 Jan 1:574:569-582. doi: 10.1016/j.scitotenv.2016.09.083. Epub 2016 Oct 14.

Authors

M Fan¹, C K Chau², E H W Chan³, J Jia⁴

Affiliations

¹ School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China.
² Department of Building Services Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region. Electronic address: chi-kwan.chau@polyu.edu.hk.
³ Department of Building and Real Estate, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region.
⁴ Department of Building Services Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region.

PMID: 27648534
DOI: 10.1016/j.scitotenv.2016.09.083

Abstract

This study formulated a new index for evaluating both the air quality and wind comfort induced by building openings at the pedestrian level of street canyons. The air pollutant concentrations and wind velocities induced by building openings were predicted by a series of CFD simulations using ANSYS Fluent software based on standard k-ɛ model. The types of opening configurations investigated inside isolated and non-isolated canyons included separations, voids and permeable elements. It was found that openings with permeability values of 10% were adequate for improving the air quality and wind comfort conditions for pedestrians after considering the reduction in development floor areas. Openings were effective in improving the air quality in isolated canyons and different types of opening configurations were suggested for different street aspect ratios. On the contrary, openings were not always found effective for non-isolated canyons if there were pollutant sources in adjacent street canyons. As such, it would also be recommended introducing openings to adjacent canyons along with openings to the target canyons. The formulated index can help city planners and building designers to strike an optimal balance between air quality and wind comfort for pedestrians when designing and planning buildings inside urban streets and thus promoting urban environmental sustainability.

Keywords: Air quality; Building openings; Street Air-Wind Index; Street canyons; Wind comfort.