Study On The Construction Of A Modified Model Of Human Thermal Comfort In The Mild Area Of The Low Latitude Plateau

Low-latitude plateau areas have both low-latitude and plateau climate characteristics,forming an annual average temperature of moderate,neither hot nor cold winter"four seasons like spring"climate,this type of area can effectively use the suitable outdoor environment for most of the year,in the creation of high-quality green buildings and good indoor environment has a unique advantage.The existing indoor environment research and related conclusions are not applicable to the low latitude plateau cities in China,and the low pressure and low oxygen environment in this region will cause people to respond to the environment differently than in the low latitude regions,so it is necessary to build a thermal comfort correction model to meet the needs of the people in this region according to the local conditions.Many studies have shown that the most commonly used model at this stage,PMV（Predicted Mean Vote）,ignores the differences in human species and the role of human adaptation to the environment,and does not correct for errors in parameters such as thermal resistance of clothing and metabolic rate estimated during its calculation,resulting in a"scissor difference"between the predicted results and the real feelings of people.scissor difference"between the predicted results and the real human feelings.In addition,the model does not consider the influence of convective heat transfer coefficient and personnel metabolic rate under the low pressure of plateau,and does not involve the physiological and psychological differences of personnel,ignoring the active adaptation of personnel to the environment and the difference with the real thermal comfort.Therefore,it is necessary to revise the thermal comfort evaluation model in accordance with the actual geographical and climatic environment and the characteristics of the population in the low-latitude plateau area.Based on the objective parameters of the environment and subjective evaluation of students in a university located in Kunming,this study adopted the method of"offline measurement+questionnaire survey"to conduct field research in several classrooms on campus from May to September 2022,a local overall thermal comfort evaluation model was established after these research.The factors that may have an impact on human thermal comfort were analyzed based on information such as gender,BMI,and length of time after entering Kunming according to the statistics in the questionnaires.Among them,the length of time after entering Kunming was set as 1,2,3,4 and 5 years as five options according to the students’time of studying in the local area.In the data processing process,1,2 and 3+years were taken as indicators because of the small number of students with 4 and 5 years of study.Subsequently,these factors were corrected in a graded manner one by one.In this study,the local overall thermal comfort evaluation model was obtained based on 18 experiments from May to September.According to the obtained model,firstly,combined with the characteristics of Kunming low-latitude plateau,the convective heat transfer coefficient and metabolic rate generated from low air pressure were firstly corrected to obtain PMV₁;secondly,considering the physiological,psychological and behavioral reactions of personnel using the adaptive coefficients were secondly corrected to obtain PMV₂;finally,corresponding to the degree of adaptation of personnel to the environment using the length of time after entering Kunming was thirdly corrected to obtain PMV₃,so as to construct a specific thermal comfort evaluation model for mild areas of low-latitude plateau in China on the basis of the original thermal comfort PMV model.When three corrections were made,it was also found that:（1）after the correction of convective heat transfer coefficient and metabolic rate,the reduction of atmospheric pressure,the comfort zone of human body moved towards higher dry bulb temperature;（2）for different BMI and gender,people with low weight are the most sensitive to changes in thermal environment;gender differences,the thermal sensory vote value of male is higher compared to female and more sensitive to changes in thermal environment These physiological differences lead to different basal metabolic rates and different physiological responses to environmental factors,which require a certain amount of time for adaptation;（3）the difference in the time of entering the local area from abroad has an impact on the adaptive capacity of people,the shorter the adaptation time to the local environment,the less adaptable to the climate,and their thermal sensation is relatively uncomfortable.The model of this study fully considers the characteristics of the population and environmental factors,modifies the influence of altitude and physiological parameters on the PMV model,and innovatively introduces the adaptation time of different people to the local environment as the population adaptation parameter.After verification and analysis,the prediction model of PMV modified three times is closer to the TSV model obtained by the actual vote of the subjects,which can produce significant and effective correction of PMV,and provide valuable theoretical basis and engineering practice support for the research of human thermal comfort model construction in the low latitude plateau and moderate areas in China...