Elemental modeling of adsorption filter efficiency for indoor air quality applications

Adsorption based air cleaning technologies have long been employed in various industrial applications but it has remained marginal in office and residential buildings. The present study presents a first step in the development of physically-based models that could help civil engineers to improve the design and maintenance of such systems by considering the complexity of the indoor air cleaning problem, especially variable concentrations, temperature and airflow rate. The breakthrough curves of six challenge gases in a packed bed of non-treated granular activated carbon were measured for gases as singles, and then as a mixture, in dry air and under isothermal conditions. On the whole, the results indicate good agreement between measured and predicted concentrations at the filter outlet. Considering the large number of contaminants that can be found in indoor settings, this suggests that the questions of efficiency and lifetime of the filter are probably much more difficult to answer than one can think. Finally, the paper discusses some possible improvements of the models as a way to increase accuracy, but also to allow for the simulation of even more realistic configurations of filter operation.