A reduced pressure delivery system for applying a reduced pressure to a tissue site is provided. The system includes a manifold having a plurality of flow channels. The manifold is configured to be placed adjacent the tissue site. A first conduit is in fluid communication with the flow channels of the manifold to deliver a reduced pressure to the flow channels. A second conduit is in fluid communication with the flow channels of the manifold and is operably connected to a valve. The valve selectively purges the second conduit with ambient air when the valve is positioned in an open position, and a controller is operably connected to the valve to place the valve in the open position for a selected amount of time at a selected interval during delivery of reduced pressure through the first conduit.