Study on the outdoor thermal environment and thermal comfort around campus clusters in subtropical urban areas

Abstract

Presently, there have been few studies on the outdoor thermal environment and thermal comfort of campus clusters in subtropical climate urban areas. In this study, first we investigated the influence of various types of design elements on the outdoor thermal environment around campus clusters in subtropical urban areas, such as pilotis, squares, and teaching building blocks. Second, we conducted a questionnaire survey on thermal sensation and thermal comfort in campus clusters to study the subjective response of young students to the outdoor thermal environment in subtropical urban areas. Assessment of thermal comfort by the SET∗ index suggests that the neutral SET∗ of young students is about 24 °C in an outdoor environment in subtropical urban areas in the summer. A 0.9 K temperature difference is observed between teaching building blocks and a grass-covered surface square, indicating the influence of the sky view factor (SVF) and heat capability of ground surface on air temperature distribution at night-time. Owing to a large SVF, more short-wave and long-wave reflections and long-wave radiations are incident on the square: attention should be paid to this fact, which may create an extremely hot outdoor thermal environment in the daytime. Influenced by MRT, the SET∗ around teaching building blocks is higher than those of the square and pilotis in the afternoon, which is expected to reduce the acceptable rate of the outdoor thermal environment. Pilotis can reduce SET∗ by 6–10 °C; therefore, the use of pilotis is encouraged to create an outdoor thermal environment of well-being in subtropical cities.