Publication date: June 2013
Source:Building and Environment, Volume 64
A large scale estimation of mean radiant temperature (t mrt ) is conducted at two sites using customised globe thermometers. The measurement points cover a variety of urban typologies such as high-rise offices, parks, large water bodies and housing apartments. Data is derived using a t mrt formula calibrated to the local climate. Measurements for clear, sunny days are used for the analysis of the average diurnal t mrt profile. The diurnal t mrt profile shows that the t mrt differential between points is most evident during daytime, and is affected most significantly by shade cast by trees and buildings. Results also show that common urban constituents such as greenery and large water bodies, while proven to effectively reduce the ambient temperature of its surroundings throughout the day, do not affect t mrt significantly after nightfall. Further analysis reveals a correlation between sky view factor and t mrt in the day. Measurement points in different parks exhibit contrasting trends in t mrt reduction. Results of the study also provide a realistic threshold for the lowering of outdoor t mrt . Trees, shrubs and green walls may be introduced into the outdoor environment with the intention of reducing t mrt to a desirable level for a specific time range.
Source:Building and Environment, Volume 64