I have 2 Noctua NF-A14 pwm 1450 rpm.I wonder if they would work better than the Helix 1750 rpm ones in pull. I have not also tried flipping the Helix ones around on the rad to intake instead of exhaust and change the side door fans around from intake to exhaust. The side door fans were on intake before when my graphics card was stock air cooled but I have it now being cooled with a swiftech water block on it so the side door as intake is not needed as much.Right now the fan config in my Cosmos 2 case is, two front as intake,2 side door fans as intake, and top fans on rad as exhaust, and rear fan on the case as exhaust.