Study On The Indoor Physical Environment Of University Classrooms In Xi’an Based On Comfort

The research on the indoor environment in university classrooms play an important role in enhancing students’ learning efficiency,improving the learning environment,reducing building energy consumption,and keeping students healthy.Therefore,this research,taking the university classrooms in Xi’an as research subjects,investigates the indoor light environment,heat and humidity environment and air quality in university classrooms by adopting questionnaire survey,field test and simulation.The main research contents and conclusions are as follows:First of all,this research pays attention to the indoor light environment of university classrooms in Xi’an.Through questionnaire survey,the researcher learns about the students’ attitudes on the indoor light environment.And by conducting field test,the current problems and changes in illuminance and visible light spectrum can be found out.Through simulating the different shading measures and the arrangement of artificial light,the suggestions for optimal layout are given.The results show that the participants’ light comfort for different areas in classroom is different,and too high or too low illuminance will both cause visual discomfort.The illuminance and visible light spectrum of different light sources vary with time and space.Simulated by Ecotect and Radiance,the indoor illuminance under different shading measures and artificial light arrangement are found.The data show that the shading ability of full shading is higher than that of half shading,and the shading ability of external shading is higher than that of internal shading.The indoor illumination changes with the shading position,louver angle,shading mode,louver width and louver spacing.Therefore,detachable movable louvers are selected when designing the inner shading of the louvers.Different ways to turn on the artificial light will also affect the indoor illumination.The way to turn on the artificial light in the classroom changes from parallel to the blackboard to vertical.When the illumination near the window area meets the learning needs,only the artificial light in the middle area and the far window area are turned on.Secondly,this research investigates the indoor thermal and humid environment in university classrooms in Xi’an.Through questionnaire survey and field test,it explores students’ satisfaction with indoor thermal environment and the variation of indoor temperature and humidity under different conditions.On the basis of indoor light environment,Ecotect is used to simulate the accumulated solar radiation of indoor windows under different louver shading measures,and the appropriate louver shading measures are obtained.The results show that,in summer,the thermal comfort of natural ventilation classroom is poor,and the thermal comfort of air-conditioned classroom is better.But in the air-conditioned classroom,the thermal comfort near the air-conditioned area is poor.In winter,the indoor thermal environment has better thermal comfort.The influence of temperature on thermal comfort is greater than that of humidity.Indoor temperature and relative humidity are mainly related to outdoor environment,indoor population and indoor air conditioning(heating)equipment.The changing trends of indoor temperature and relative humidity is opposite,and also the indoor and outdoor temperature.The results present that the full shading is better than the half shading in summer,and the external shading is slightly better thans internal shading.In winter,half shading is better than full shading,and internal shading is better than external shading.Finally,the present research conducts a questionnaire survey on indoor air quality in two different types of classrooms to obtain students’ satisfaction with the air quality.By separately testing the indoor CO2 concentration in these two types of classroom,the variation rules of the indoor CO2 concentration with the number of people are obtained.The results present that the indoor air quality in a naturally ventilated classroom is better than that in a closed classroom.Regardless of the classroom type and season,the change of indoor CO2 concentration is mainly determined by the number of people and vatilation in the classroom.Therefore,indoor natural ventilation should be strengthened without affecting the indoor temperature.According to the research on the indoor light environment,heat and humidity environment and air quality in university classrooms in Xi’an,this paper obtains the current problems and the changing rules with time and space.Combined with the characteristics of climate in Xi’an,the optimization suggestions are put forwords.Thus,this research can provide practical references for the design and renovation of buildings in university in Xi’an.