Study On Design Strategy For Thermal Environments Of Living Street Canyons In Guangzhou

Street canyon is the space that people, buildings and climate interact intensively and thespace for pedestrians’ activities. The thermal environment of street canyon is important forsafety and comfort of pedestrians and energy consumption of surrounding buildings. Thepresent study is aimed to analyse thermal environmental qualities and propose designstrategies for the living street canyons in Guangzhou by ways of ENVI-met simulation, fieldsurway and measurements. The main work and conclusions are as follows:The main characteristics of the living street canyon in Guangzhou are obtained through afield survey of20street canyons as: branch-based streets and supplemented by secondaryroads, east-west and south-north orientated, surrounded by high-rise and multi-storeybuildings with aspect ratio of0.4~3, covering sidewalk pavements and buildings by lightmaterirals with albedo of0.25~0.5and greened by Ficus microcarpa with green coverage rateof9%to33%.It is found by a field study of two typical living street canyons in Guangzhou that thedistribution of air temperature inside canyons is mainly determined by solar radiation and thewhole thermal environment of street canyons has delayed characteristics. Throughcomparison with the field measurements, it is found that the simulation of ENVI-met is betterfor air temperature and humidity than for MRT and air speed, and the RMSE is2.09℃andthe consistency index is0.57for prediction of SET inside street canyons.It is shown by the orthogonal experiment on thermal environments of the living streetcanyons in Guangzhou by ENVI-met simulation that the contribution on thermal environmentis largest for orientation, followed by aspect ratio, greening and albedo, where thecontribution of greening is bigger at noon than in the morning and at night. It is also shownthat southeast-northwest is the best, and east-west is better than south-north in the morningand at noon but worse at night. The bigger aspect ratio is, the better thermal environment ofsteet canyon. Steets with uniform building height are better than those with non-uniformbuilding height.Considering the field survey and current standards, the design strategies and methods areproposed based on optimizations for the living street canyons in Guangzhou.