A filtering device 10 that includes a housing 12 having a plurality of subsections 32, 34, and 36 where each subsection is adapted to receive a filter element 26, 28, and 30. An inlet 18 is disposed at a first location on the housing 12, and an upstream air distribution system is placed in fluid communication with the inlet 18 and with each of the subsections 32, 34, and 36. A downstream air distribution system is located in fluid communication with each subsection 32, 34, and 36, and an outlet 20 in fluid communication with the downstream air distribution system. The upstream and downstream air distribution systems are constructed to cause the same airflow velocity through each subsection. Using such a construction, overall product service life may be increased while minimizing pressure resistance of the total filter.