Urban geometry and the microclimate of street canyons in tropical climate

• Published in: Building and environment 2020-02, Vol.169, p.106547, Article 106547
• Main Authors: Muniz-Gäal, Lígia Parreira, Pezzuto, Cláudia Cotrim, Carvalho, Marcius Fabius Henriques de, Mota, Lia Toledo Moreira
• Format: Article
• Language: English
• Subjects: Air temperature; Aspect ratio; Buildings; Canyon aspect ratio; Computer applications; Computer simulation; ENVI-met; Microclimate; Outdoor thermal comfort; Parameters; Shading; Software; Street canyons; Summer; Sustainability; Thermal comfort; Urban areas; Urban geometry; Urban street canyons; Wind; Wind speed
• ISSN: 0360-1323; 1873-684X
• DOI: 10.1016/j.buildenv.2019.106547

The objective of this study is to assess whether geometric parameters of urban street canyons affect their microclimates and pedestrian thermal comfort. Understanding the effect of these parameters on the microclimate of urban street canyons is crucial for achieving sustainability between urban occupation and thermal comfort. This study used the computational tool ENVI-met 4.0 preview. The study was conducted in the city of Campinas, São Paulo, Brazil, which has Cwa climate. A total of 36 scenarios, with and without space between buildings, were simulated for winter and summer. The scenarios differed in their aspect ratio (H/W) (avenue (H/W  2.0) canyons) and length-to-height (L/H) ratio (short (L/H  7.0) canyons). Canyon performance was assessed by comparing the air temperature, wind speed, and physiological equivalent temperature (PET). The results revealed that canyons with a higher H/W aspect ratio increase the wind speed and shading by buildings, thereby improving the thermal comfort at the pedestrian level, especially in the summer. Conversely, an increase in the L/H ratio had no significant effect on the thermal comfort sensation at the pedestrian level, which was similar to the scenario without space between buildings. •36 urban street canyons scenarios, with and without space between buildings, were simulated for winter and summer periods.•The geometric parameters of urban street canyons strongly affect the microclimate and level of thermal comfort at pedestrian level.•Higher H/W aspect ratios improved thermal comfort at pedestrian level, especially in summer.•Lengthening the canyon (higher L/H ratio) caused no significant variations in thermal comfort at pedestrian level.•Canyons with higher aspect ratios H/W had increased wind speeds and shading from buildings.