Research On Outdoor Thermal Environment Evaluation And Renovation Strategy Of Old Communities In Temperate Area

The rapid development of urbanization makes the living quality of the original building space decline,which leads to the deterioration of the thermal environment quality of the outdoor space in the old community.In the relatively backward mild climate areas,on the one hand,regional characteristics make the annual temperature difference generally small and daily temperature difference large.On the other hand,different from cold areas,hot summer and cold winter areas,the existing thermal engineering codes in mild climate areas have no mandatory requirements in terms of building layout and building maintenance.This flexibility of construction also leads to uneven outdoor thermal environment experience of buildings and the quality of outdoor thermal environment cannot be guaranteed.Compared with the newly constructed residential areas,the construction standards of the old and dense urban communities are lower,and the ambient temperature,solar radiation,wind speed and other conditions of the outdoor space are poor,which is easy to make residents have bad thermal environment experience.Therefore,it is necessary to carry out research on outdoor space thermal environment of old communities in mild climate areas,understand the current situation of outdoor thermal environment,determine residents’satisfaction with outdoor space thermal environment and its influence degree,use thermal environment comfort evaluation index to determine residents’thermal comfort range,and based on this,provide relevant suggestions on thermal environment for the subsequent renovation and renewal of outdoor space in old communities.The above research will be carried out from the following aspects:First of all,taking Guiyang as an example,four representative old communities are selected for thermal environment test and questionnaire survey,so as to understand the outdoor thermal environment of the old community in this area,the thermal comfort of residents and the characteristics of residents’activities.The results show that residents expect the wind speed to increase in spring and autumn,prefer the environment with lower temperature in summer,and expect the wind speed to decrease in winter.In the order of seasons,the thermal environment acceptance of residents in each season was84%,83%,90%and 61%,and the overall thermal environment acceptance in winter was the lowest.Secondly,correlation analysis was carried out between PET,SET~*and UTCI three thermal environment comfort indexes and residents’thermal comfort conditions in different seasons.After calculating the prediction accuracy of thermal sensation and comfort range of each thermal environment comfort index,the applicable indexes for each season were determined.Among them,the applicable indexes for thermal environment sensation analysis in different seasons were:Spring(SET~*),summer,autumn and winter(UTCI);The applicable indexes of thermal environment comfort range in each season and the corresponding indexes of thermal comfort range in each season are as follows:spring(SET~*:20.8℃～26.1℃),summer(SET~*:20.2℃～31.9℃),autumn(PET≤25.5℃),winter(UTCI:9.9℃～13.6℃).Finally,through the analysis of the comfort range of thermal sensation in each season and the uncomfortable factors of residents’thermal environment,it is found that residents’outdoor thermal environment comfort in winter is significantly worse than that in other seasons.Through further research,the direction of improvement of thermal environment comfort in winter is determined to increase air temperature,increase average radiation temperature and reduce wind speed.According to the different contents of outdoor space transformation,the corresponding thermal environment improvement strategy is proposed.Through the above research,the outdoor thermal environment characteristics of old communities in mild climate areas are mastered,and the corresponding thermal environment improvement strategies are put forward.On the one hand,it enriches the theory of outdoor space thermal environment in old communities in mild climate areas.On the other hand,in view of the reality of the development stage of the old community stock,it provides ideas and guidance for improving the outdoor thermal environment of the old community,which also has reference significance for the thermal environment transformation of the urban built space.