You need a much bigger fan and a much bigger intake. You're not getting good results because you're pushing a fan of unknown cfm with a 2" intake, expecting it to effectively clear a room efficiently.

How big is the room? How many cubic feet are you trying to clear, and what would be efficient enough? An 8'x10'x8' room is 640 cu ft. A 50cfm fan would take nearly 13 minutes to clear the room, where a 150cfm fan would do it in a little over 4 minutes.