John Curran wrote:
Chilled water to the rack implies multiple CDU's with a colorful hose and valve system within the computer room (effectively a miniature version of the facility chilled water loop). Trying to eliminate potential failure modes in that setup will be quite the adventure, which depending on your availability target may be a non-issue or a great reason to consider moving to new space.
Actually it wouldn't have to be pressurized at all if you located a large tank containing chilled water above and to the side, with a no-kink, straight line to the tank. N+1 chiller units could feed the tank. Thermo-siphoning would occur (though usually done with a cold line at the bottom and a return, warmed line at the top of the cooling device) as the warm water rises to the chilled tank and more chilled water flows down to the intake. You would of course have to figure out how to monitor/cut off/contain any leaks. Advantage is that cooling would continue up to the limit of the BTUs stored in the chilled water tank, even in the absence of power. Cordially Patrick Giagnocavo patrick@zill.net