If you want a fairly cheap fix I'd go to home depot and get a duct fan, 6" or preferably 8". Somthing like http://www.homedepot.com/h_d1/N-5yc...splay?langId=-1&storeId=10051&catalogId=10053 . Cheap (under 40$) and won't handle bends in ducting very well but in a straight line will move you a couple hundred CFM fairly quietly. They also come in smaller sizes and cheaper prices. Of course cheaper then that would be a few PC fans.