Tree-configuration and species effects on the indoor and outdoor thermal condition and energy performance of courtyard buildings

Abstract

The effectiveness of vegetation coverage in mitigating human heat stress and improving thermal comfort of spaces is indispensable. Outdoor spaces of academic courtyard buildings are not merely used for educational objectives; whereas a wide range of social activities are occurring in their courtyard environments. Tree cover is proposed as a passive strategy to improve thermal and microclimatic conditions as well as energy efficiency of buildings. In present paper, the impact of tree-configuration and species on the indoor and outdoor thermal comfort and energy demand of courtyard buildings is studied using the field measurements and numerical simulation methods. An integrated approach of ENVI-met and DesignBuilder is adopted to simulate two actual courtyard buildings, with and without trees, located at the Imam Khomeini International University (IKIU) campus in Qazvin, Iran. The numerical methods are validated through comparing the observed and simulated parameters (indoor and outdoor) of both buildings during the shortest and longest days of the year (June 21st and December 21st of 2018). The local trees provide the most particular protected microclimate in the courtyard space. The results demonstrate a significant improvement in the mean Physiological Equivalent Temperature (PET) during the cold and warm periods of the year. This paper also shows that the deciduous and coniferous trees that located in the vicinity of the internal thermal zones, decrease annual energy demand and the number of discomfort hours from April to October.