Global warming may becoming suspect in more eyes these days and "going green" may not have the same cache as a few years ago, but the fact is that energy costs still represent a large portion of the operational budget at most data centers, so it only makes sense to trim down consumption as much as possible.
And while great strides have been made with virtualization and other energy-saving techniques lately, cooling issues are likely to remain front and center as organizations continue to push the density levels in both the server and storage farm. The conundrum here is that the more tightly you pack heat-generating equipment, the more energy you consume trying to cool the air in and around it.
That's why a number of organizations are turning toward the concept of "free cooling." Although it's not entirely free, the idea is to make use of freely available, natural resources to keep temperatures from exceeding operational limits. Solutions range from using outside cold air to tapping into natural water supplies and even planting grass on the roof to cut down on solar radiation.
PEER 1 Hosting, for example, recently constructed a $40 million, 40,000 square foot data center in Toronto that features a new generation of Variable Frequency Drive centrifugal chillers and external condenser towers that are able to tap into outside air, which can easily drop to 10 degrees C in the winter months. Local well water also feeds an internal cooling infrastructure.
Meanwhile, WETA Digital, the special effects house responsible for much of the wizardry in movies like Avatar and Lord of the Rings, uses both water cooling and free cooling courtesy of the chilly climate in Wellington, New Zealand, to keep the lid on more than 4,000 HP blade servers packed into a 10,000 square foot facility. The company keeps the thermostat at about 25 degrees C, which is warmer than most managers prefer, but is still cool enough to keep the center humming, even at full data loads.
And in Wynhard, England, HP recently opened a new facility designed to use free cooling virtually year-round. The center circulates fresh air through a series of inlet fans and bag filters, mixing it with warmer internal air to maintain a constant 24 degrees C. The company reports that its construction costs were about 6 percent above normal, but it expects to make up the difference relatively quickly through lower energy costs.
While it may be efficient, free cooling is not without risks, according to Emerson Network Power's Fred Stack. The chief concern is availability, which could suffer if Mother Nature decides she doesn't much care about enterprise economics and decides to turn the heat up. It's important to have a back-up solution available at all times, plus a healthy dose of monitoring and automation, not only to prevent a catastrophe but to maximize efficiency during normal operation. Naturally, Emerson has a full line of cooling systems with Liebert ICOM controls to do just that.
The ability to utilize free cooling will depend very much on the climate and geography of your region. I wouldn't expect to see tremendous gains in, say, Death Valley, for example.
But as more organizations shift their data over to the cloud, it could very well be that it won't matter where actual facilities are located before too long. In that case, it would make sense to place resources and capacities where they can be operated most effectively and efficiently.