An Adaptive Thermal Comfort Model For A University In Xi’an

The design standard of indoor comfortable temperature is not only related to the overall energy consumption of the building,but also directly affects the comfort of indoor personnel.China has a vast territory,and residents are affected by many factors,such as climate,living habits,cultural background,building type and thermal experience.Therefore,it is obviously not advisable to formulate a unified design standard nationwide.Taking this as an opportunity,this paper carried out field investigation and test of thermal comfort in college students’ dormitories in Xi ’an area,and recorded the actual thermal sensation of the subjects on the ASHRAE thermal sensation scale of 7.Statistical analysis method was used to analyze the data in detail,and the corresponding "human thermal comfort climate adaptability model" was given,and the following conclusions were drawn:(1)The main control and regulation measures of indoor thermal environment in college dormitory in Xi ’an are centralized heating,followed by air conditioning.Summer is mainly natural ventilation,followed by air conditioning.When the outdoor air temperature is below32℃ in summer and the indoor operating temperature is below 28℃,people mostly use natural ventilation,whereas people will gradually begin to use air conditioning to cool down.For the time being,this point can be considered as the turning point for natural ventilation and air conditioning in summer.(2)Statistics of indoor and outdoor parameters in winter and summer: the average indoor temperature was 17.7℃ and 26.1℃;Relative humidity 37.6%,67.2%;Airflow speed0.01m/s,0.13m/s;Clothing thermal resistance 1.36 clo,0.31clo;The indoor average radiation temperature was slightly higher than the operating temperature,with an average difference of 0.18℃ and 0.15℃.Outdoor air temperature 4.1℃,28.0℃;The relative humidity is37.6% and 67.2%.(3)In winter,the PMV prediction index estimated the actual thermal sensation of human body relatively low.After revising the PMV prediction index,that is,multiplying by the coefficient E =0.65,the measured MTS index could be predicted relatively well.In the summer with natural ventilation as the main factor,the difference between PMV prediction index and MTS measured index is small,and PMV can be used to predict people’s actual thermal sensation.(4)The corresponding human thermal neutral temperature in winter and summer was18.0℃ and 25.1℃,respectively;Ⅰ level comfortable temperature range is 16.9 ～ 19.1 ℃,respectively 23.4 ～ 26.7 ℃;Ⅱ level comfortable temperature range is 15.7 ～ 20.2 ℃,respectively 21.7 ～ 28.4 ℃;The optimum range of comfortable temperature is 16.9～20.2℃and 23.1～27.8℃ respectively.(5)Thermoneutral temperature is not a fixed value,but changes with the change of outdoor temperature,and there is a functional relationship between it and the outdoor average air temperature.Based on the data obtained,the climate adaptation model of human thermal comfort in college dormitory in Xi ’an area is established,which is of practical significance to predict the thermal neutral temperature under different climate conditions,and to accurately evaluate the indoor environment and building energy conservation.