Make your side intake, and your back exahust. Try to put like a filter on the fan. They make fan filters but why buy one when you can make yuor own
But im like messed up, my back is intake, my side is intake, my top is exahust, my two front at the bottom are exahust, i have one under my optical drives, with a hole in the front of my case at the top as exahust, and my psu is exahust also. lol.
Just make it intake and try to put some kind of covering on it