Some of the 1st generation bigger miners can put out insane amounts of heat.  I have an Avalon 2 200 GHs miner that I had to put in the attic as it generated soo much heat in my climate controlled computer room that my air handler couldn't keep up with the heat and the room temp went from 74F to 79F with the AC running constantly.  I looked at water cooling for my system as well, but I have great ventilation in the attic so was just easier to put it up there.