Evaluating and improving the adaptability of commonly used indices for predicting outdoor thermal sensation in hot and humid residential areas of China

Studies have used different indicators to quantify outdoor thermal comfort in humid and hot areas of China. This study aimed to evaluate the applicability of three commonly used thermal indicators and to further improve their applicability by revising their scales. The database included 1005 interviews accompanied by field measurements. Two statistical and three quantitative criteria were established to assess the performance of the selected thermal indices, and the corrected scales of the thermal indices were modified using three techniques. The results indicate that although the original scales of the thermal indices had a high correlation coefficient with thermal sensation votes (TSV), the percentage of correct predictions was relatively low (<23.0%). The corrected scales determined by the percentage of thermal acceptability range (TAR) correlated better with TSV than those obtained by linear regression and probit analyses. The revised scales of universal thermal climate index (UTCI) had a higher percentage of correct predictions (35.3%) than did the other scales. Therefore, TAR is recommended for scale revision and UTCI is recommended for thermal comfort evaluation in hot and humid residential areas in China. The results of this study offer a reference for landscape planners to design more comfortable outdoor spaces in hot and humid residential areas of China.