By enclosing the side walls and ceiling of my "room within a room", I force all 10,000 CFM of air out through the mining rigs instead of escaping out the sides and top where there is less resistance.  I also plan to do a better job sealing the openings on the shelving unit itself, again to do everything I can to force all the air to move through the GPUs.  You will notice on one of the pics I have an online duct fan blowing across my 8x1060 EVGA rig with a Colorful mining mobo with real close spacing.  Right now, that 10,000 CFM intake fan is not able to move air at a high enough velocity through it to keep the 1060's cool.  I'm hoping by sealing all other openings, I'll bring the velocity up to where I don't need any "booster" fans.  Also, be sealing everything, I'm hoping I'll only need to run the intake and exhaust fans at like 50% speed most of the time.  Both 10K fans are connected to a single VFD so that I can run the fans any any speed I want.  Getting a computer interface for it so that I can automate the speed at which the fans run.  At full blast they consume 900 watts.  But running them at 40Hz, they only use 400 watts.  So running them faster than I need to waste a lot of power.