So my process has evolved quite a bit since I originally started. I kept my mining rig in the coldest part of my house that I could find, and put a 20" box fan behind it to pull fresh, cool air over the cards. If you are running just one mining rig, that should provide sufficient cooling capacity.

At this point, I keep them in dedicated commercial space that circulates cold winter air into the room, and exhausts the hot air with the use of inline fans and a home-made exhaust manifold and system of duct work. (I used to run ~26,000 BTUs of AC into the room, but its far more expensive than circulating air.)

More in depth explanations are coming soon, I'll make sure to get them edited and posted ASAP.