Nice Rack!! We have a slightly larger operation, around 200 miners. Had a heat issue as soon as we turned on more than 30, we also burnt our power drop of the warehouse. Needless to say we finally got a new drop and phase 3 power, so we could plug all the miners in. We ended up creating a HOT BOX to take all the heat out and installed 2 fans at the end of the box to suck all the air out and offset our positive air pressure in the box and 2 fans in the room to offset the negative pressure in the room. Here's some before and after pics, this setup created temps of 100+ in the room; needless to say, our little funneling of the miner exhaust has dropped the temp in the room almost 20 degrees.

https://imgur.com/a/f0NzKoo