Microclimate-driven strategies for thermally comfortable university open spaces in cold regions of China.

University open spaces are predominantly utilized by students, with outdoor thermal comfort on campus significantly enhancing their physical and mental well-being. This study investigates the thermal perceptions (sensation, comfort, and acceptability) of students at a university in Xi'an, China, employing meteorological measurements, questionnaires, and activity logs. The Physiological Equivalent Temperature (PET) was utilized to establish a thermal baseline. We documented the spatiotemporal distribution of students in open spaces and analyzed the correlation between their thermal perceptions and environmental factors. Furthermore, an optimal design strategy for campus open spaces, tailored to students' needs and based on meteorological data, attendance patterns, and thermal perceptions, is proposed. Key findings include: (1) Globe temperature (Tg) and wind speed (Va), which are the primary meteorological determinants of college students' thermal sensation, with relative humidity (RH) playing a secondary role. (2) Variations in Neutral Physiological Equivalent Temperature (NPET) and its range (NPETR) are observed across different open spaces, indicating distinct thermal experiences. The NPET at Entrance Square (ES) is 17.3 °C, NPETR is 13.3-21.4 °C; the NPET at Leisure Garden (LG) is 21.8 °C, NPETR is 16.4-27.3 °C; the NPET at Life Square (LS) is 21 °C, NPETR is 15.9-26 °C; the NPET at Cultural Square (CS) is 18 °C, NPETR is 11.6-24.7 °C. (3) The utilization of campus open spaces by college students is significantly influenced by the outdoor microclimate, available facilities, and spatial configurations, leading to diverse behavioral adaptations for thermal regulation. (4) Incorporating students' physical, physiological, and psychological preferences, the study proposes an optimal design strategy for enhancing the thermal comfort in campus open spaces.