CO2 tracer gas concentration decay method for measuring air change rate

Shuqing Cui (1) , Michael Cohen (1) , Pascal Stabat (1) , Dominique Marchio (1)

1 CES - Centre Efficacité Énergétique des Systèmes

The measure of air change rate (ACR) in building is a difficult and usually expensive task. The tracer gas method is the reference technique but its implementation is difficult and the interpretation of results is not straightforward. In the present work, the concentration decay method by multiple CO2 transmitters is experimentally validated in the case of cross-ventilation. It is observed that in-situ CO2 transmitters lead to ACR values in good agreement with reference measurements obtained from mechanically controlled values. Whereas multiple transmitters in different sampling positions show the imperfect mixing, a sensor located at the outlet or an averaged value of all sensors can provide an accurate measure of the ACR. Moreover, the spatial variation of CO2 concentration can be used to assess the ventilation efficiency in the test chamber. Different measures and calculation methods are discussed, and the uncertainty analysis of each method is carried out.

Mots clés: Gas tracer; In-situ measurement; Concentration decay; Uncertainty analysis

Domaines: Sciences de l'ingénieur [physics]; Energétique

Shuqing Cui, Michael Cohen, Pascal Stabat, Dominique Marchio. CO2 tracer gas concentration decay method for measuring air change rate. Building and Environment, 2015, Vol 84, pp.162-169. ⟨10.1016/j.buildenv.2014.11.007⟩. ⟨hal-01299866⟩