Measurement of air exchange rates in different indoor environments using continuous CO_2 sensors

摘要

A new air exchange rate(AER) monitoring method using continuous CO 2 sensors was developed and validated through both laboratory experiments and field studies.Controlled laboratory simulation tests were conducted in a 1-m 3 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 CO 2 sensors coupled with data loggers.Indoor temperature,relative humidity(RH),and CO 2 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.