How cold is it at your location and are you venting the room? As your cooling looks a little under powered for brute forcing it with 60 gpus even with the 14 nm technology.
Hot as hell coming into summer, 30-35 degree days increasing, cards still only run at 60-65 degrees, room is hot though.
Currently have the door to the room open completely, will be installing roof vents to pull the hot air out of the room in the coming weeks.