Measuring Air Exchanges Rates Using Continuous CO2 Sensors

Measuring AERs in an effective, real-time, easy and low-cost way is still a challenge, especially in China where rooms were usually naturally ventilated but not with the Heating, Ventilating and Air Conditioning (HVAC) system. A new AER monitoring method using continuous CO2 sensor was validated through both laboratory experiments and field studies. Controlled laboratory simulation tests were conducted in a 1 m environmental chamber at different AERs (0.1~10.0 hr-1). AERs were determined using steady-state method and decay method based on box model assumptions. Field tests were conducted in apartments, offices, classrooms, dormitories and meeting rooms in during 3-5 weekdays with four sets of sensors coupled with data loggers. Statistic results indicated that good laboratory performance was achieved. In spite of limitations, this new method, along with mini-sized and easily operational instrumentations which provide sufficient continuous data, demonstrated an effective way to measure AERs in various indoor environments.