Development of a methodology for in-board assessment of the efficiency of air quality filters

Abstract : As large contributor of fine particles, road transport is a major concern for motorist and leads to a continuous improvement of HVAC systems and cabin filters. For the latter, performance evaluation is mainly tested in laboratory according to standards (e.g. ISO/TS 11155-1) (i) with normalized particles which are not representatives of the particles found in urban air and (ii) with the use of optical indicators that make measurement assumptions e.g. a constant particle density. Thus, there is a lack in the literature about the efficiency of cabin filter in real conditions. Only, few studies concern the determination of the efficiency of a cabin filter in real roadway conditions (Liu et al. 2011), and all of them use optical indicators. Therefore, the project QABINE 2 (Qualité de l’Air dans les haBItacles eN déplacEment 2) aims to develop a protocol for the evaluation of the filtration efficiency of cabin-filters under real driving conditions near Paris. Here, the aerosol sampling methodology developed for QABINE 2 is presented with emphasis on describing how the sampling point upstream the filter was designed in order to be representative of the outside air concentrations sucked by HVAC system of the vehicle. Then, the efficiency evaluation of two different filters is performed through two in-field campaigns and almost thirty-seven different tests.