Data Center Racks

A separate cooling device probably isn't necessary if air flow in the room is decent. But if you have 43U of hot-running equipment--your rack is filled with blade servers and SAN switches--look for latch-on cooling systems. Liebert's add-on, Extreme Density, is designed for its enterprise-class racks.

These cooling systems tend to be liquid-based. Some use tap water, while others use chemicals that require less pressure. Most products also support simple fan-in-ceiling cooling add-ons. Determine your equipment needs, then ask your vendors what they recommend for cooling. Some vendors have calculated the "optimal" amount of airspace in the front door, some offer side-to-side cooling attachments to cover Cisco switches, some have extra fan arrangements, and, of course, some have liquid-based cooling systems.

If you need multiple racks, consider buying an extra cooling unit or a more advanced cooling system. APC, Dell and Liebert offer systems designed for larger setups and include modules that will help cool multiple racks in a non-data-center environment.

Got Power?

With regard to UPSs, you want enough redundant power to give you sufficient time to reach the room--physically or by way of remote administration tools--to power-down each piece of equipment gracefully during an outage. Allow a minimum of 15 minutes (per rack) to accomplish this.