The Old Outdoor Thermal Comfort Evaluation Research In Lhasa

Since the 21 st century,people pay more and more attention to the sustainable and healthy development of cities,in the process of urbanization,building healthy and comfortable outdoor space has gradually become one of the hot topics of current research.At the same time,since our country has entered the aging country,the aging problems that come one after another make the physical needs,psychological needs and behavior of the elderly get unprecedented attention.With the renewal and development of urban space,as the material medium for the outdoor activities of the elderly,the research on the aging of urban outdoor space will become particularly important,especially in specific areas Creating suitable outdoor thermal environment is the key to meet the comfort needs of the elderly outdoor activities,and it is also one of the important factors to be considered in urban outdoor space design and planning.As the holy land of Tibetan Buddhism,Lhasa has entered an aging society since2017.Due to the special historical background and cultural characteristics of Lhasa,the elderly in this area have a very strong demand for outdoor activities.The unique high altitude and cold climate conditions also lead to the specificity of outdoor thermal comfort needs of the elderly in this area,while Lhasa has been lagging behind in the development of the city The theoretical study of urban construction and the current situation of urban thermal environment deterioration are the sufficient conditions for further study of outdoor thermal comfort.Based on the form of measurement and questionnaire,this study discusses and analyzes the thermal feeling and thermal comfort evaluation of the elderly in Lhasa city through the method of mathematical analysis.Firstly,according to the spatial characteristics and types of activities,the typical outdoor activity spaces of the elderly are classified,and four typical outdoor activity spaces of the elderly are defined,which are named as nursing,religious,entertainment and rest spaces respectively;secondly,under the condition of no interference local time shading,instruments are arranged at the appropriate measuring points during the sunshine period to measure the thermal environment,and the nearest combination is selected Then,through the correlation analysis of thermal environment parameters and thermal sensation,thermal environment parameters and thermal comfort,we get the characteristics of thermal sensitivity of the elderly,that is,in winter,the thermal sensitivity of the elderly is wind speed > sunshine > temperature > humidity,in summer,temperature > wind speed > sunshine >humidity,and found that in winter,the elderly are more sensitive to The sensitivity of temperature and humidity is weaker than that in summer,but the sensitivity to sunshine is higher than that in summer.The influence of sunshine and wind environment(wind speed and air temperature)on thermal comfort of the elderly in winter is more prominent than that in summer.Finally,pet is selected as the evaluation index of outdoor thermal comfort by comparison,and the modified algorithm under low pressure is used to calculate the outdoor thermal comfort of the elderly The temperature of pet is 8.4 ℃ in winter and 19.6 ℃ in summer,while the temperature range of pet is 15.5-25 ℃.