External fan to keep cooler for desktop?

My new system is coming. It has two internal fans, but the room it is in gets bot in summer. I have two floor fans to blow on it, but was wondering if there is a particularly good kind of external fan I could set next to the tower on the table where the computer is. Any ideas?

 

You don't need anything fancy, jst a steady supply of room temp (or even better yet cool) to the intake fans and/or vents. Perhaps a box fan placed in your window may help.