We have a new 2 MW data centre at Cambridge which uses water cooling and has a target PUE < 1.2.
There are four 700kW (I think) external heat exchangers to cool the water. The expectation is that they will just act as simple radiators most of the time. If the outside temperature rises above about 25 C they use water to provide evaporative cooling. There are two different setups inside which both use the same hot/cold water supply. In the HPC hall there are back-of-rack cooling systems, with water supplied to each rack. There's a picture of the HPC's current setup in their temporary home which uses the same cooling technology though the physical layout is different. (The new hall has more leak protection!) http://www.uis.cam.ac.uk/features/hpcs-joins-uis The other halls have enclosed hot aisles, and the hot air passes via a plenum to the CRAH units at the side of the room, which cool it and return it to the hall's main airspace. Tony. -- f.anthony.n.finch <[email protected]> http://dotat.at/ Trafalgar: Cyclonic in northwest, otherwise mainly northerly or northwesterly 5 or 6. Slight or moderate. Showers in northwest. Good.
