if the funds are there i would recomend buying a vortex or similar inline fan. I am using a 600 watt with a cool tube in a closet very similar to yours and it is staying nice and cool in there with my 6" vortex fan. I also have the fan and filter mounted in the attic with bungees so it has almost no sound. I built a shelf about 1.5 feet off the ground and put in 3 3 inch abs elbow's, so it appears the closet is normal with no light coming from under the door.