Jul 01 2006

Keeping Your Cool

High-density servers, high-capacity storage force companies to deal with the heat.

When Michael Magaldi bought a Hewlett-Packard blade server chassis last summer to help meet the growing computing needs at St. Mary's and All Angels, a private grade school in Aliso Viejo, Calif., he was thinking ahead. The chassis houses up to eight servers, enough processing power to keep up with the school's expanding use of video clips and PowerPoint presentations by students and faculty, plus plenty of room to grow.



But one thing Magaldi didn't consider was the level of heat generated by the high-density server unit, which almost immediately after installation raised the temperature in the server room — the size of a walk-in closet — enough to cause a meltdown of the storage area network (SAN) device running next to it. "I didn't really think about cooling [beforehand]; we're not engineers here, we're small-business people," Magaldi says. "But man, the blades generate heat like you wouldn't believe. We learned a lot."



As the temperature in the school's server room reached 90 degrees Fahrenheit, 20 degrees hotter than most information technology equipment generally should be kept, the SAN suffered an interrupt. Luckily, no data was lost. Still, it was clear that the school's air conditioning system was not equipped to handle this kind of heat. Magaldi had the school's heating, ventilating and air conditioning supplier install a 1-ton unit simply to cool the server closet that now keeps the space at 70 degrees around the clock.



Although this surprise expense caught Magaldi off guard — the dedicated AC unit cost about $3,000, plus $1,500 for installation — he believes it was worth it to protect his investment in server equipment. Plus, the school is now saving money on its electric bill because the combination of two cooling units operates more efficiently than did the previously overworked central HVAC system. Magaldi estimates that the school has shaved roughly $300 from its $12,000 monthly power costs.



Heating Up



With high-density servers such as blades emerging as good solutions even for smaller companies with significant processing needs (see BizTech Tech Update, June 2006), and greater storage requirements making SANs and other high-density storage popular, there is more processing and disk-spinning going on in confined spaces. This "densification," as HP calls it, is transforming data-center cooling from a nice-to-have option to a necessity.



"Cooling is something you definitely need to consider — eventually the heat has to go somewhere," says Raymond DeCrescente, chief technology officer with the Capital Region Orthopaedic Group, a medical practice and surgery center supporting 24 doctors in Albany, N.Y. Two years ago, the center bought three blade server systems from HP to power its management system, tax system and finance database, as well as its digital X-rays, MRI and other images. Because the image files require a lot of storage capacity, the center also had to re-examine its storage plans.



After much lobbying, DeCrescente received the budget and space to build a data center, complete with power and cooling management systems. "Once we knew we were going to start sizing storage up, I said, 'This is the time to do this,' " DeCrescente says of the data center, which he estimates cost roughly $160,000 to build.



But for smaller, fast-growth companies, budgetary or space constraints keep full-blown data centers from being an option. Instead, many businesses cobble together makeshift centers in unused offices, small extra rooms or spare closets — completely overlooking the likely cooling demands.



"I don't think cooling bubbles up very high or very often in terms of small-business concerns, which is why it's key for the channel partners to point out the needs for cooling capacity," says Ray Boggs, vice president of small/medium business and home-office research for IDC of Framingham, Mass. Often smaller companies are still grappling with "having dedicated server space, as opposed to sticking them wherever it's convenient."



Wallet Buster



With power costs on the rise and computer power consumption multiplying every few years, cooling must be considered because of a simple physics fact: For every watt of power consumed, a watt of heat is generated. IBM says the average 1U-rack server, which consumed 80 watts of power 10 years ago, now requires as much as 450 watts of power. Meanwhile, the cost of electric power has steadily risen over the past five years. The average price of electricity to commercial customers rose from 7.26 cents per kilowatt an hour in 1999 to 8.16 cents in 2004, according to the most recent report by the U.S. Energy Information Administration.



"Power has gone from a teeny little line item you could dismiss as nothing to a pretty major cost," says Scott Tease, manager of IBM's BladeCenter product marketing.



Luckily, not every company needs to build a high-end data center to save on power costs and protect IT investments. There are variety of offerings on the market that can be bought with new servers, or even after the fact, that do an efficient job of cooling the areas where servers and storage are kept, therefore saving on ambient cooling costs.



One example is IBM's Cool Blue, a rear-door heat exchanger that cools the air coming from servers by using water, much like the early mainframes did. Cool Blue can be used with any IBM rack-mountable server, including blade servers, and costs about $6,500 for the rack and heat exchanger.



HP sells a self-contained unit — the Modular Cooling System — that attaches to a rack and also uses water to cool air across the front of the rack, says Ron Mann, director of rack and power systems with HP's Enterprise Storage and Servers Group. The unit, which starts at $30,500, cools equipment that consumes up to 30 kilowatts in a single rack.



American Power Conversion offers a number of products, ranging from its portable AC PA4000, which cools up to 4 kilowatts and starts at $2,500, to its ceiling-mounted NetworkAir CM, which cools up to 17 kilowatts and starts at $5,800.


A Few Chilling Alternatives


Product Cost Description
APC NetworkAir PA Portable $3,510 Localized cooling for small rooms and data closets
APC NetworkAir RM air distribution unit $612 2U rack-mounted fan works with existing air conditioning system to deliver cool air to equipment contained in a rack enclosure
HP Modular Cooling System $37,407 Self-contained water-cooled rack system
Rittal TopTherm wall-mount cooling unit $1,476 Cools up to 300 watts
Intel SC5200 Server Chassis $1,003 5U rack mount with hot-swap redundant power and integrated cooling


CEO takeaway
• Before buying new servers or high-density storage equipment, determine the new hardware's cooling requirements (suppliers should be able to do this for you) and assess whether your current cooling system can accommodate the additional heat.
• If deciding between traditional HVAC equipment and a dedicated server-room cooling unit, estimate the additional electricity costs needed to cool the data center area versus the acquisition and installation costs (if applicable) of a dedicated unit. When power costs are considered, often the dedicated unit will cost less over time because of more efficient operation.
• Cabinet fans and other low-cost cooling approaches may work fine today, but factor in future data center growth and increasing electricity costs to decide if a more robust solution makes sense.