Research On Classroom Thermal Environment Under The Comprehensive Impact Of Thermal Comfort And Learning Performance During Winter In Rural Areas Of Northwest China

As a major learning place,the merits of classroom environment directly affect pupils'mental health and learning performance.It is dominated by adolescents,their activitiesare mostly meditation.Thermal demand of the pupils is quite different with the adults.The current thermal comfort evaluation model,indicators and methods are all based on the average level of the whole society,and it is difficult to directly guide the design of classroom thermal environment in primary and secondary school.In addition,another important basis for the design of classroom thermal environment is to improve the learning performance.In the current standards,the determination of indoor parameter is mainly based on single thermal comfort index,but few relates to the impact of learning performance on the indoor thermal environment,the combination of the two is more rare.In this paper,the pupils of primary and secondary school were taken as the research object during winter in the rural areas of Northwest China to analyze the thermal comfort level and the regulation of pupils'thermal adaptability in controlled and uncontrolled environments.The adaptive thermal comfort model for primary and secondary school pupils under colder environment in countryside was proposed,which was based on the behavioral habits,psychological expectations and physiological regulation.The quantitative relationship between indoor thermal environment and thermal comfort was established,with satisfaction rate of adolescents was set as a thermal comfort evaluation index.Based on the thinking way of adolescents,a comprehensive assessment method of learning performance was proposed with four evaluation factors:"Attention,Perception,Comprehension and Deduction"by the theoretical analysis of information processing in the human brain.Through the human experimental study of controlled classroom,combined with the subjective evaluation,psychological and physiological responses,the relationship between temperature or carbon dioxide concentration and learning performance were analyzed.In order to eliminate individual differences,group pass rate was proposed to characterize the learning performance index.The quantitative relationship among group pass rate,learning performance and temperature was established.The selection criteria and the applicable range of the indoor thermal environment parameters were proposed,taken into consideration the comprehensive effect of thermal comfort and learning performance by introducing the theory of spatial analysis.The temperature range with both higher comfort and better learning performance in primary and secondary classrooms was recommended.The main conclusions of this research are:?1?Lower thermal comfort temperature for pupils in cold classrooms in NorthwestThe acceptable temperature ranges of 90%pupil were 12.0¹8.0?.The high limit of thermal comfort temperature is lower than the low comfort temperature recommended by the ASHRAE standard in winter by 3?.And the clothing resistance is about 0.5clo higher than that of the recommendation in ASHRAE standard during winter.The adaptive thermal comfort model was raised for primary and secondary school pupils,which was t_comf=0.27t_out+13.8(2.0??t_out?10.3?).?2?Higher learning performance in colder environmentsWhen the average thermal sensation votes?TSV?was about-1.4,the corresponding temperature was about 14.0?,then the optimal learning performance was obtained.The learning performance in warm environment?TSV=+3?decreased more than that in cold environment?TSV=-3?by about 10.3%.It was found that the optimal learning performance for"Attention,Perception,Comprehension and Deduction"could be achieved at 13.4?,13.1?,12.8? and 14.9?,respectively.In addition,the influence of CO₂ on learning performance under comfortable temperature conditions in this paper was significantly different according to the type of tasks,and the impacts on four factors of assessing learning performance were quite different.?3?Lower recommended temperature range of classroom with higher comfort and learning performance than the current standardsAccording to the spatial relationship among the temperatures,satisfaction rate and pass rate,the range of the design parameters in classroom under different combinations of thermal comfort and learning performance were obtained.The high limit of recommended temperature with higher comfort and learning performance decreased5? than the low limits of international standards,which could effectively reduce the energy consumption of teaching buildings in winter.The comprehensive effect of classroom environment on adolescents'thermal comfort and learning performance in primary and secondary school was researched.Taking into account both of them,the method of thermal environment design was established for classroom,which fully explored the prerequisites for the energy saving potential of such buildings.It can provide a theoretical basis for the improvement of classroom environment design standards.