Effects of vertical greenery on mean radiant temperature in the tropical urban environment

<p>Studies on vertical greenery generally focus on the measurement of air temperature, surface temperature and cooling load. There is a lack of information on how vertical greenery can influence outdoor thermal comfort. The objective of this study is to quantify the effects of mean radiant temperature (t_mrt ), as the first step towards determining the thermal quality of outdoor space due to installation of vertical greenery. </p> <p>The t_mrt of two green walls (Green Wall A and Green Wall B) was measured up to 2 m away at intervals of 0.5 m. Two datasets were obtained, one consisting of t_mrt , surface and air temperature collected from the two green walls and the second for just green wall A and the exposed concrete wall after Green Wall B was removed. t_mrt was measured using customised globe thermometers calibrated for local use. Data was analysed using a GIS, thus enabling convenient visual comparison between t_mrt profiles at different times. The diurnal t_mrt profile was altered significantly due to the installation of vertical greenery. When both green walls were present the peak t_mrt occurred at 15:00 h, but with more concrete exposed when one wall was removed, the peak occurred at 17:00 h and was 10.9–12.9◦ higher at 0.5 m away from the wall. Vertical greenery thus helped to reduce t_mrt both during the day and at night, to varying extents. The proposed methodology enables systematic quantification of the effects of vertical greenery on t_mrt.</p>