[Aloisius]

Did they say it was efficient? The "closed loop" is only one part of the system that cycles water between the heat exchanger and the building/servers.

The second part of the system is an open loop that uses water to cool the closed loop at the heat exchanger.

[seg_lol]

They implied that DCs somehow save water because of being closed loop. The closed loop is a red herring, since the outer loop dumps potable water.