Abstract: A stepped plenum system is provided for distributing particulate laden gas to a plurality of filter bags in a baghouse under substantially equal flow rate and pressure conditions. The stepped plenum system includes an inlet conduit and a plurality of outlet conduits. Gas is inserted into the inlet cross-sectional area of the inlet conduit and is directed to the outlet conduits through a stepped pattern design. The first outlet conduit and the second outlet conduit are in fluid communication with the inlet conduit. The second outlet conduit is longitudinally displaced from the first outlet conduit and provides for a second flow region which is of lower cross-sectional flow area than an initial flow region of the inlet conduit. Each of the outlet conduits include a plurality of inlet vane members which capture and redirect the flow of the gases into a direction which channels the gaseous flow into the respective outlet conduits.