How to chill out

Any data center modernization project must address heat

It isn’t sexy, but IT managers will tell you that keeping a data center properly cooled is an ongoing challenge.

An average rack of servers once consumed roughly five kilowatts per hour. Today it’s not unusual for a rack of servers to consume seven, 15 or up to 30 kWh in ultradense, blade-filled racks. That’s expensive—and hot.

But Richard Sawyer of American Power Conversion says even setups as dense as 45 kWh can be properly ventilated (though the denser the configuration, the more expensive it will be to cool). He and other experts provide these pointers.

TIP 1: Consider the layout of your server racks. Most experts advocate the hot aisle-cold aisle approach, where the servers are arranged in rows so they all blow heat into common areas, where it can then be blown away.

TIP 2: Snap in “blanking panels” over unused portions of the rack. The panels stop the hot air from being sucked through the cabinet and mixing with the cooler air on the other side.

TIP 3: If you’re piping air under raised floors, remove any unnecessary objects in that space. “Every time you put in a cable, take the cable it’s replacing out,” Sawyer said. “If there is a cable there, there isn’t any air.”

TIP 4: If your racks are getting dense, you may want to consider supplemental cooling. Both APC and Liebert Corp. sell cooling and heat removal units that can be attached to the front or the back of server cabinets. In addition, APC has started selling slim in-row cooling units that take up half the floor space of a server cabinet. When placed in between cabinets, these units suck out hot air and blow in cool. Liebert offers mobile units that can be moved around to where the hot spots are.

TIP 5: If your data center is still running hot (20 kWh per rack or above), you may want to explore water cooling. Normally feared by admins because leaks could cause damage, water—and other liquid coolants—can be far more efficient at removing heat than air.

TIP 6: Be creative when working through cooling and power problems. Sometimes low-cost solutions are right in front of you. For instance, take a look at the air outside your data center. Although in many cases, ambient air may not match the humidity, purity or temperature requirements for data centers, when it does, it can save big money.

About the Author

Connect with the GCN staff on Twitter @GCNtech.


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