Check out their site. The miners are submerged in mineral oil. Mineral oil is circulated to a heat exchanger that requires a small amount of water input to maintain evaporative cooling. I believe the container pictured has several 'sealed' assemblies inside.
Hrm nothing small about the evap coolers water intake i've seen in DC and they wouldnt touch this much power dissipation. I'm not an engineer so i can't tell exactly if these numbers could add up, but from what i know and from my own, evaporation cooling require dry intake, which would not work in all climates. This is because once the relative humidity is high due to evaporation, no more cooling effect is produced.