Long-term vertical thermal bioclimate based on measurements on Taipei 101 Tower

The rapid growth of urban populations and the scarcity of living space have necessitated the construction of high-rise buildings in most cities. However, the impact of these structures on vertical thermal environments remains inadequately understood, posing risks to urban dwellers. While high-rise buildings are typically equipped with central air conditioning systems, their outdoor environments still influence energy consumption and natural ventilation. 

This study assessed vertical urban bioclimatic conditions on the Taipei 101 Tower using Physiologically Equivalent Temperature (PET) and modified PET (mPET), analyzing a decade-long dataset (2012-2021) collected from balcony measurements at two heights (150 m and 350 m), with PET showing a wider range (-3.8 ºC to 46.4 ºC) than mPET (0.3 ºC to 42.8 ºC), indicating more extreme thermal sensations.

Winter thermal perceptions were significantly influenced by variations in meso-scale weather systems, with cold patterns leading to colder thermal perceptions at both elevations. In contrast, warmer weather conditions resulted in warmer thermal perceptions. In addition to large-scale atmospheric influences, the observed homogenization of hot thermal perceptions at both elevations during the summers of 2020 and 2021 may largely be attributed to the influence of increasing high-rise buildings through urban development.

This study highlights the significant impacts of large-scale weather patterns and climate change on vertical thermal perception in cold seasons. Furthermore, global warming likely contributes to increasing hot thermal perceptions during spring and autumn. These findings have important implications for urban planning and climate adaptation strategies in high-rise urban environments. The dense high-rise developments may negatively expand the vertical scope of heat island effects, and future policy initiatives will require unprecedented approaches in urban planning and design of climate adaptations with serious considerations. 

Keywords: Physiologically Equivalent Temperature, modified Physiologically Equivalent Temperature, Taipei 101 Tower, Vertical Thermal Perception