I designed this blower duct as I found I liked to see what was going on.

I was using a Active Cooling Fan Duct for Replicator 1 / Duplicator 4 / FlashForge http://www.thingiverse.com/thing:295317, Which worked great but it blocked the view from the front.

This blower moves much more air then the 40x40x10 fan used previously so cools much better, great for larger overhangs. But the downside is it is a bit noisier as well.