Abstract: A ceiling structure within a cleanroom, including an array of conventional HEPA filters supported in openings of a grid support structure, wherein the ceiling structure includes a gel track coupled near a lowest interior perimeter of each of the openings of the grid support structure. HEPA filters including a peripheral flange are suspended in the ceiling structure by having a ceiling edge of the peripheral flange immersed in the gel track in near proximity with the ceiling level. An inclined channel is formed along an inclined wall of the gel track such that a downward extension of the inclined wall projects into the vortex region under the grid support structure. Filtered air passing from the HEPA filter is then directed into this flow channel at a sufficient rate of speed to flush the particulate contaminate from the vortex region.