One of the principal issues in maintaining the very high availability required for mission-critical facility data centers is how to deliver cooling effectively and efficiently to all the equipment, wherever it is in the room.
The significant power densities in modern data centers mean that this is a substantial task and justifies significant focus if it is to be implemented in such a way that achieves the cooling objective at low cost and without significantly interfering with operational objectives. People often forget that the primary purpose of the cooling system is to cool the electronics; historically, data centers were simply treated in the same way as other occupied spaces.
Figure 17.1 shows that to cool the electronic component it is important to take responsibility for configuration/design of cooling for the IT Equipment itself, how it is cooled in any rack/cabinet, and how those cabinets are cooled in the data hall. The broken line represents the break in ownership of the problem; at the electronics scale, the manufacturer is responsible; at the room scale, the facility manager is responsible. There is an obvious danger that the rack/cabinet configuration and cooling falls between the two.