Assessing the Impact of Urban Geometry on Outdoor Thermal Comfort in Microclimate Scale: A Case Study of the Open Space of Goldasht Residential Complex in Shiraz
Subject Areas : Regional Planningسینا Karamirad 1 , محمد aliabadi 2 , امین Habibi 3
1 - architect
2 - faculty member at the University of Shiraz
3 - faculty member at the University of Shiraz
Keywords: Envi-met, Urban microclimate, urban geometry, outdoor thermal comfort,
Abstract :
Pedestrian’s thermal comfort plays a significant role in designing urban spaces and urban complexes. Understanding the relationship among climatic variables that have significant impact on thermal comfort and the geometry of the urban structures raises the possibility of finding the optimal solutions to enhance the quality of urban environments. "Mean radiant temperature" is one of the key factors needed to be taken into account in comparison with other climatic factors. This principal has much more impact on outdoor thermal comfort in urban environments. Accordingly, the current study aimed at focusing on urban geometry and form factors, such as the sky view factor, urban canyon properties, and orientation which have an essential impact on determining and creating outdoor thermal comfort conditions in urban open spaces. This is an applied research with a quantitative research design. Thus, a combined research strategy based on a dual measurement of logical reasoning and analysis of library resources on one hand and software evaluating (ENVI-met 4 basic) on the other has been used to analyse the open spaces of "Maaliabad Goldasht Residential Complex". To conduct the study, climatic variables were studied in nine selected areas in the site. Accordingly, through calculating the thermal comfort index, PMV, the nine points were compared through their geometry and configuration. The analysis of the gathered data was performed both at 9am and 5pm. The coefficients R=0.84, R=0.86 were obtained. The research findings demonstrated a strong correlation between mean radiant temperature (MRT) and the thermal comfort index (PMV). Hence, as MRT increases, heat stress emerges. Consequently, the quality of urban design and its affecting agents (sky view factor, urban canyon and the orientation) are needed to be seriously considered as the major factors in providing thermal comfort in the urban environment, specifically in warm seasons.
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