Urban morphology as an adaptation strategy to improve outdoor thermal comfort in urban residential community of new assiut city, Egypt

Abstract

Improvement of outer spaces between residential buildings to increase social activities in a hot arid climate has been subject to several studies but few of them focused on combination of shading and vegetation scenarios or hybrid scenarios for different outdoor residential canyons ratios. Therefore, thermal comfort for residences in a hot dry climate should be studied in the residential community. This study aims to evaluate and improve thermal comfort and resident's thermal sensation in open spaces of an urban residential community in New Assiut City, Egypt. The thermal condition of outer spaces of the urban residential community was evaluated based on using field monitoring for different outdoor parameters in different canyon ratios ranging between 0.24 and 0.6 H/W and improvement for Outdoor Thermal Comfort (OTC) based on ENVI-met 4.4.5 simulation model, using six design scenarios. Thermal comfort values, by Physiological Equivalent Temperature (PET), were compared. The results concluded significant reduction of PET is achieved for outdoor spaces in deep canyon with a ratio of 0.6 H/W compared to shallow canyon with a ratio of 0.24 H/W using three hybrid scenarios which include adding grass, trees as Cassia Javanica, and semi-shading (50 %). Also, using hybrid scenarios reduces surface temperature for the outer building façade with a temperature difference range between 3 and 10 kelvins at 15:00 in different canyon locations. This reduction of temperature reduces heat transfer to the indoor building environment and heat stress to the outer space. Thus, this study focuses on increasing tree density and semi-shading for open spaces between residential buildings to increase the benefit of the outer environment for residents in the residential community of new cities in a hot arid climate. The results of this study helps planners and architects to incorporate proposed methodology in the design process of future residential complex and current cases.