Bull’s Cool Cabinet Door is the ideal complement to an existing air-conditioning system, or a cost-efficient alternative to an air-conditioning installation.
Server density in HPC centers has increased so much in recent years that air-conditioning systems cannot cope with additional servers. Upgrading or replacing the computer room air-conditioning system to produce more, cooler air is a costly solution, both in terms of investment and power consumption. Bull proposes a more energy-efficient solution: removing heat closer to the source, i.e. cooling at rack level.
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The Bull Cool Cabinet Door is a water-cooled door that hinges to the back of a standard Bull 42U x 19” cabinet. This active rear door extracts and removes the heat generated within the rack, using chilled water supplied by a central chiller plant. The resulting water-cooled cabinet accommodates any device designed for standard 19” racks. |
With the Bull Cool Cabinet Door, racks can be filled up to their limit, to reach unprecedented compute density:
- up to 40 KW per rack, i.e. 28 KW/m²,
- 29U/m², or 42U + 6 PDUs over 1.44m².
Three times as many servers can be housed in the same floor space, compared to standard air-cooled cabinets.
Water is a much more efficient heat transport medium than air. Water-cooling also optimizes thermal management by removing heat at cabinet level, before it enters the room. As a result, only 600 W are needed to extract 40 KW, instead of 2.6 KW with air-conditioning.
The air leaving the cabinet is at room temperature, which eliminates hot spots – a good thing for overall MTBF!
The Cool Cabinet Door offers more performance and density than its competitors and is priced well below any equivalent offer. Contact your Bull representative for an estimate!

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