Study On Indoor Thermal Environment And Air Quality Of Classrooms In A University In Xi'an

The indoor environment of a building is one of the most intimate and frequent environments for people.The problem of indoor thermal environment and air quality has received widespread attention in recent years.People have recognized the urgency of studying and improving indoor thermal environment and air quality.importance.College classrooms are not only the place for teachers to impart knowledge,but also the main place for students to acquire knowledge.Therefore,it is of great significance to study and improve the indoor thermal environment and air quality in classrooms and improve the physical and mental health of teachers and students.In this paper,we use the on-the-spot test of college classroom environment,the questionnaire survey on college students during class and after class,and use the test data to do theoretical calculations to study the indoor thermal environment and air quality of a university classroom in Xi'an.Through comparative analysis,the main problems existed in the indoor thermal environment and air quality in classrooms in colleges and universities in Xi'an.?1?In winter,due to the disrepair of radiators in classrooms of teaching buildings,serious aging and insufficient heating result in low indoor temperatures.In winter,the outdoor climate is relatively dry.The use of heating in the classroom reduces the relative humidity in the room.At the same time,there is no humidification equipment in the classroom,resulting in low indoor relative humidity,dry air,and poor human comfort.?2?In summer,due to the high outdoor temperature,there are no cooling measures in the room.There are many people in the classroom and the ventilation is poor.The heat cannot be dissipated in time.This leads to high indoor temperatures and the body feels hot.?3?When the outdoor winter weather is haze,the highest values of PM2.5 and PM10 in the classroom?PM2.5 is 585.3?g/m³,and PM10 is 837.5?g/m³?reach 7.8 times the regulated value and 5.6 Times,indoor CO₂ up to 1846.3ppm,exceeding the standard value of 84.6%,serious indoor air pollution.?4?The value of TVOC in art classrooms is higher than the standard value,especially the oil painting classrooms and the lacquer painting classrooms have reached 4.7 times and7.5 times the standard value respectively.The harmful odors stay in the classroom for a long time,and they are painted and painted.The lifelong cancer risk value?LCR?of students in classrooms reached 2.5 and 3.7 times the specified value,especially for art teachers,whose LCR value can reach 74 times the standard value.The health of art teachers and students has great potential risks..?5?The average concentration of respirable particles in a traditional chalk board classroom is as high as 409.6?g/m³,which reaches a level of heavy pollution.When the board was wiped,the concentration of respirable particles was 1067.4?g/m³,which was 7.1times the specified standard value.Especially when the board was wiped,the concentration of respirable particles at the teacher's location was as high as 4250.6?g/m³,which was the specified standard value.28.3 times,chalk teaching will lead to poor indoor air quality,especially for teachers and front row students.?6?Using the grey evaluation method,it is concluded that in the experimental buildings tested in the winter,the air quality in classrooms of teaching buildings largely depends on the number of classrooms in the classroom and the flow of people.The larger the number of classrooms and the greater the flow of people,brings outdoor dust into the room and brings in the room's inhaled dust,resulting in a deterioration of air quality in the classroom.In a well-ventilated classroom in summer,the geographical location of the school building and the surrounding environment greatly affect the quality of the air quality in the classroom.When classrooms are close to the street and there is a lot of traffic around them,the air quality in the classroom will deteriorate.To solve these problems,it is recommended that air purifiers and air humidifiers be installed in the classrooms,and the heating facilities in the classrooms be renovated,and the area of greenery and water in the campus should be increased to solve these problems.It is hoped that these measures will provide architects with some feasible and economical suggestions for improving the indoor thermal environment and air quality in the design of university teaching buildings.This article has reference value for the study of indoor thermal environment and air quality of public buildings in Xi'an.