Filter assembly for motor vehicle ventilation, heating or air conditioning system has frame side walls shaped to match edges of filter

The filter assembly, comprising a pleated filter element (31) surrounded at least partly by a plastic frame, has the side walls (33, 34) of the frame shaped to match the V-shaped edges (42) of the filter element, having at least alternate apertures so that the filter edges are not blocked. The filter element is made from a non-woven card layer containing long thermoplastic fibres, a mesh layer and a supple woven layer with activated carbon. The side walls are joined at one end of the assembly by a transverse facade (36) with a rim (37) and fastening lugs (45), and at the other end by a base (41) with a seal. Dispositif de filtration destiné à équiper un appareil d'aération et/ ou de chauffage et/ ou de climatisation, en particulier pour véhicule automobile, constitué d'un média filtrant (31) comportant des plis et entouré au moins partiellement d'un cadre (32) le cadre (32) est en matière plastique et fixé au média filtrant (31), les parois latérales (33, 34, 133) du cadre (32) épousent la forme en V des extrémités des plis (42) du média filtrant (31) et comprennent au moins de manière alternée des ouvertures.