Going with 2x engine cooling fans from a local carparts warehouse.
14" 2200rpm 80watt 12V - 530cfm, so 1060cfm total.
70$ new for both so fairly cheap, hopefully that is enough and if not a third will be added for 1590cfm total.
I tried these fans in the GPU days in 2012. They are extremely fucking loud and they get very hot. I had to disconnect them after a few days because they smelled like burning. I don't think they are meant to be run all the time. I used gable fans from home dept instead. 2200CFM.
They are simply not meant for this usage.
Btw, like these setups, but I still like the ghetto 100 GPU 5870 setups better hahaha...
i was just gonna get these from Menard's and pop them (hanging) from jousts in front of the window(above the miners) blowing out
https://www.menards.com/main/p-2381238-c-12728.htm
see this link for pictures (will not repost large pic from prev post above) the 2nd Titan album is newest pics of basement setup
http://lostgonzo.imgur.com/
anyway with the above link should be obvious...get the air out and have all bsmt windows open .to vent thru the bsmt etc
should work (if not i have other probs like 100 degree F days or some such