Shahrzad Talebsafa - Faculty of Architecture & Urban Planning, Semnan University, Iran
Masoud Taheri Shahraeini - Faculty of Architectural Engineering and Urbanism. Shahrood University of Technology, Shahrood, Iran
Xiaoshan Yang - College of Architecture, Nanjing Tech University, Nanjing, China
Mohammadreza Rabiei - Faculty of Mathematical Sciences, Shahrood University of Technology, Shahrood, Iran

Thermal comfort is one of the most important factors affecting the quality of outdoor space. This study investigates the effect of shade on outdoor thermal comfort during the hot season. For this purpose, meteorological measurement and questionnaire surveys were conducted simultaneously at four points of the university campus in the cold semi-arid climate of Shahrood, Iran. Then, the ENVI-met V۴ was validated and implemented to examine the impact of different shading scenarios on outdoor thermal comfort. The neutral physiological equivalent temperature (PET) and the upper boundary of the PET comfort range have been obtained at ۲۱.۹°C and ۲۶.۹°C, respectively. The results demonstrated that the plants shade creates the most acceptable thermal environment. Also, shading caused a significant reduction in the PET value and thermal stress while increasing the comfort levels and the comfort hours during the sunny days. Furthermore, simulation results indicated that creating shade in the open space by a structure contribute to lower level of mean radiant temperature up to ۳۲.۶°C and up to ۱۷°C for the PET. Moreover, a maximum mitigation effect in mean radiant temperature of ۲۴.۷۹°C and ۱۳.۷°C for the PET obtained as a result of providing shade by trees. The highest reduction of PET (۱۷.۲°C) were achieved by the combination of trees and the architectural shade. The outcomes of this research provide useful design recommendations to improve outdoor thermal comfort.

thermal comfort, Outdoor space, Shade, Physiological equivalent temperature, ENVI-met