Studies On Outdoor Thermal Environment Indices And Its Application Based On Campus In Guangzhou

Highly relevant to an individual’s thermal perception, the thermal environment in outdoor public spaces play an important role on the use of such spaces including producing activity and entertainment, etc. More strigent outdoor thermal environment pursued rather than just developing healthy warning systems, with the development of the socioeconomic level. Thermal indices are important for assessing human thermal perception and have been a major part of thermal comfort research, which lead to a clear standard and better understanding of the thermal environment conditions. However, both thermal indices and thermal model were mostly addressed by developed countries in Europe or North America, whose climatic and culture have a big difference in our country. The question is that how about the applicability when applied in hot and humid regions directly, since lots of study have demonstrated a variation of thermal thresholds in different region. Unfortunately, study rarely been addressed in such field in Guangzhou. This research focus on analysis common thermal indices currently applied to outdoor thermal environment, based on that the calibration and contrastive analysis of thermal indices were conducted, hope better indicators can be used in outdoor thermal purposes.The study located in Guangzhou University and the surrounding in this study. Physical measurements and meanwhile a questionnaire survey were conducted to assess the thermal comfort of subjects from August to October, and 1582 effective questionnaires were collected. After that SPSS 18.0 statistical software was taken to the statistic analysis. The neutral value of thermal indices were firstly analyzed through linear regression model. While thermal comfort range were compared based on four different methods including box plot, actual unacceptability, actual percent dissatisfied and normal distribution examination respectively, then the preferred value by logistical regression model, as well as the impact of the gender on thermal comfort. Based on that, the applicability of thermal indices were summarized. To enhance applicability of thermal indices, three different calibrated methods, including linear regression quadratic regression as well as logistic analysis, were applied and compared combination of three statistical criteria in this study, which are spearman correlation coefficient, Gamma coefficient and predicting accuracy. Then the optical regression model and thermal indices scales were conducted, aim to enhance the applicability of thermal indices.Finally, multiple stepwise and logistic regression analysis were conducted, and two new thermal indices ASV* and Logistic regression model were presented, which will more suitable for Guangzhou climate, provide a reference to the environment designer. Coupled with ASV*, logit model and common outdoor thermal comfort indices PET and SET*, contrastive analysis between thermal sensation and velocity and solar radiation were conducted quantitatively. The importance and potential of shade and wind were emphasized in this study, which had been proved that will mitigate greatly the heat stress by reducing solar radiation gains on pedestrian and enhance draft sensation when the urban heat island is intensity during summer in Guangzhou.