Estimating the Effects of Wall Greening on Improving the Thermal Environment Using the Indices of WBGT and SET*

Abstract

In this study, the temperature control effects of wall greening, which is attracting attention as a countermeasure against the heat island phenomenon in cities, were quantitatively assessed by measuring the temperatures of green panels and concrete walls (painted white) using MRT, WBGT, and SET* as thermal indices. Comparison of MRT values calculated from head/short-wave radiometer measurements and blackball temperatures showed that the former value could be approximated to the latter by correcting the incident solar radiation monitored by the radiometer by solar altitude. The resultant MRT showed that the green panels lowered the temperature by about 11 C at peak hours. WBGT values showed drops of 1 to 2 C at peak hours, and SET* values showed drops of 1 to 2 C throughout the day. Thus, these indices were effective for quantitatively assessing the temperature-reducing effects of green panels.