Studies of thermal comfort and space use in an urban park square in cool and cold seasons in Shanghai

Abstract

Outdoor open space is important to cities and can provide benefits for healthy urban living. Among the many factors that affect space quality and space use, thermal comfort has drawn increasing attention from both climatologists and planners. Previous studies mostly focus on hot seasons when the primary concern is to avoid solar exposure and mitigate heat stress. In Shanghai, because of the high indoor humidity, people prefer to go outdoors and enjoy more sunshine in autumn and winter. This paper presents a thermal comfort survey in one urban park in Shanghai from November to January to investigate the role thermal comfort plays in affecting people's evaluation of the outdoor space and activity. Meteorological measurements, questionnaire surveys and unobtrusive observations were carried out. Computer simulations were conducted to evaluate the micro-meteorological conditions. The physiological equivalent temperature (PET) was used to evaluate people's objective thermal comfort level based on micro-meteorological conditions. It is found that visitors' overall comfort was largely affected by their subjective thermal sensation vote (TSV). In winter TSV showed the strongest positive relationship with air temperature and solar radiation, which are also the two most important factors that affect visitors' space use. The study reveals that the neutral PET in Shanghai in winter is around 15–29 °C. It was also found that duration of stay and length of residence in Shanghai affected visitors' thermal adaptation. This study can provide understandings of people's outdoor thermal comfort in autumn and winter in Shanghai and help promote outdoor space use.