Measurement of air exchange rates in different indoor environments using continuous CO2 sensors.
A new air exchange rate (AER) monitoring method using continuous CO2 sensors was developed and validated through both laboratory experiments and field studies. Controlled laboratory simulation tests were conducted in a 1-m3 environmental chamber at different AERs (0.1-10.0 hr(-1)). AERs were determined using the decay method based on box model assumptions. Field tests were conducted in classrooms, dormitories, meeting rooms and apartments during 2-5 weekdays using CO2 sensors coupled with data loggers. Indoor temperature, relative humidity (RH), and CO2 concentrations were continuously monitored while outdoor parameters combined with on-site climate conditions were recorded. Statistical results indicated that good laboratory performance was achieved: duplicate precision was within 10%, and the measured AERs were 90%-120% of the real AERs. Average AERs were 1.22, 1.37, 1.10, 1.91 and 0.73 hr(-1) in dormitories, air-conditioned classrooms, classrooms with an air circulation cooling system, reading rooms, and meeting rooms, respectively. In an elderly particulate matter exposure study, all the homes had AER values ranging from 0.29 to 3.46 hr(-1) in fall, and 0.12 to 1.39 hr(-1) in winter with a median AER of 1.15.
State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Sciences and Engineering, Nankai University, Tianjin 300071, China. yanyou@rcees.ac.cn
Yan
Y
You
Can
C
Niu
Jian
J
Zhou
Yating
Y
Liu
Zhipeng
Z
Bai
Jiefeng
J
Zhang
Fei
F
He
Nan
N
Zhang
D000368:Aged; D000388:Air / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000032:analysis*; D002245:Carbon Dioxide / Q000032:analysis*; D003198:Computer Simulation; D004781:Environmental Exposure; D004784:Environmental Monitoring / Q000295:instrumentation* / Q000379:methods*; D006801:Humans; D006813:Humidity; D008956:Models, Chemical; D052638:Particulate Matter / Q000032:analysis; D012111:Residence Characteristics; D012621:Seasons; D013696:Temperature; D014495:Universities; D014691:Ventilation
D052638:Particulate Matter; D002245:Carbon Dioxide