Experimental Research And Evaluation On Indoor Air Quality Of Typical Urban Underground Buildings

In recent years, a large number of underground buildings was built rapidly due to the shortage of land resources in our country. But its indoor air quality was serious, and many studies showed that the indoor air quality of underground buildings were usually worse than the ground buildings.Firstly, the existing studies related to indoor air quality were mainly about the ground buildings; secondly, indoor air quality was described when objective factors and people’ feeling were both taken into account in ASHRAE Standard 62-1989. But the current indoor standards about the draft of limitation of pollutants’ concentration was mainly from the perspective of human health, but not personnel subjective feeling. And sometimes people may not feel uncomfortable when the concentrations of contaminants were not exceeding the standards in room. Therefore, human health and satisfaction both should be taken into account when the indoor air quality was evaluated.Given the above problems, this subject research will mainly focus on three typical types of underground buildings in Xi’an. Specific research methods and mianly contents are as follows:Firstly:(1) Temperature, humidity, and representative pollutants, including CO, CO2, TVOC, HCHO and PM10 will be monitored and analyzed in these three types of underground buildings.(2) The method of Integrated Pollution Index will be taken to divide the pros and cons of indoor air quality in these buildings.Secondly: To get subjective satisfaction evaluation on indoor air quality from people by questionnaire, and evaluation value S by subjective satisfaction rating scale in these buildings.Finally:(1) The scatter plot is made by the corresponding relationship of people’ satisfaction and pollutants’ concentrations.(2) The relationship between people’ satisfaction and each pollutant’ concentration is got by comparing the results of linear and polynomial fitting committed by origin software, and then each pollutant limit of human satisfaction.(3) Theoretical analysis of Gray System is used to analyze the effection of individual pollutants on human satisfaction.Conclusions:(1) There were many types of indoor pollutants and part of them exceed standard value, and TVOC and PM10 were the main contaminants in underground buildings.(2) In these three types of underground buildings, underground fashion malls the most polluted, followed by underground food city, underground Electric City the least.(3) The relationship between each pollutant and staff’ satisfaction to indoor air quality was given by combining the actual monitoring and questionnaire survey, and then, each pollutant limit of human satisfaction was given:CO2:0.096%(summer situation)<0.10%(A standard)<0.112%(winter situation)<0.15%( B standard);TVOC : 0.60 mg/m3(A standard) < 0.794 mg/m3(summer situation) < 0.809 mg/m3(winter situation);HCHO:0.081 mg/m3(winter situation)<0.088 mg/m3(summer situation)<0.10 mg/m3(A standard);PM10 : 0.150 mg/m3(A standard) < 0.185 mg/m3(summer situation) < 0.242 mg/m3(winter situation);NOTE: A standard for the "Indoor Air Quality Standards", B Standard as "Hygientic requirements for peacetime ultilization of civil air defence works."(4) The descending order of the degree of each pollutant impact on people’ satisfaction are HCHO, TVOC, CO2, PM10, CO both in summer or winter by Analysis of Gray Correlation.