Very cool place, and very impressive. Alex, I'm sure you guys know what you're doing, but MidnightSensi would be the first guy here that I would bug about ventilation design/technique. He's attached PDFs for me before that get into a lot of detail about ventilation techniques for commercial racks, however, I'm not sure how much he can help you with this horizontal center . . . definitely worth asking though, I think . . .