Understanding urban transient human comfort for more pedestrian friendly design of urban spaces in the summer months of high density tropical cities (14629516) (1 Jan 17 - 31 Dec 19)
• Researchers: NG Yan Yung, Kevin LAU
• Funding Amount: HK$731,134
• Funding source: Research Grants Council - General Research Fund

In tropical cities, urban spaces are one’s extended living spaces. Pedestrianization promotes a healthier and more sustainable urban environment, improves the well-being of urban dwellers, and save transport energy. This study intends to understand and quantify the dynamic and transient human comfort of city dwellers so as to provide insights to the planning and design of more pedestrian friendly urban spaces in high density sub-tropical cities. Outdoor thermal comfort studies have proved that urban design has a great influence on pedestrians’ thermal comfort; its assessment helps to understand the quality and usage of the pedestrian environment. However, the majority of outdoor thermal comfort studies perceive pedestrian thermal comfort as “static”. The dynamic multiple-use of urban spaces and the highly inhomogeneous urban morphology in high-density cities of the tropics are seldom considered. The transient nature of human thermal comfort has been discussed in some indoor studies. Transient conditions are experienced when people move between spaces with a wide range of microclimatic conditions. In high-density outdoor environment like Hong Kong, pedestrians experience highly variable microclimatic conditions within short distances. However, the application of the concept of transient thermal comfort in outdoor environment is rather limited and the use of longitudinal field surveys is relatively rare, which leads to a lack of understanding about how pedestrians respond to the changes of the outdoor environment.

The proposed study aims to contribute by: (A) conducting longitudinal field measurements and surveys in order to establish a better understanding of pedestrian thermal comfort in the summer months of sub-tropical high-density urban conditions; (B) determining the dynamic thresholds of microclimatic conditions which pedestrians may find comfort when they travel through different urban settings; (C) based on the above findings, developing a dynamic human thermal comfort model that relates human thermal sensation and the built environment; and (D) establishing urban design guidelines for urban planning and design practitioners. Linking urban meteorology, urban design and outdoor thermal comfort, this study aims to provide a comprehensive understanding and quantification of the transient nature of pedestrian thermal comfort. Findings will, for example, inform the Hong Kong Planning Standards and Guidelines (HKPSG), and the current Hong Kong Government planning efforts of “HK2030+” towards a more livable environment. The study findings will also be useful for urban planners and designers in other sub-tropical high-density cities experiencing increasing urbanization.