Some Data Centers Resist Higher Operating Temperatures, Despite Energy Savings
Currently new data centers are being designed to run at higher temperatures, which increases the number of hours free cooling is available, says Beaty, since at times a cooler outdoor climate is being used without mechanical refrigeration or cooling. One advantage of the new ASHRAE temperatures is that they allow a data center flexibility to go to a cooler temperature to take advantage of lower outdoor temperatures, even if typically runs at a higher temperature. "For example, if an operator was to select a maximum operating temperature of 78 F, when it is 60 F outside, there would be no reason to not operate the data center at something less than 78 F such as 68 F," says Beaty.
Using the higher end of the new temperature ranges can significantly reduce cooling energy use in chilled water systems. "Normally the water in the chiller would be cooled to 44 degrees, but if they take it to 50 degrees, it requires half of the energy," says Jim McEnteggart, vice president of Primary Integration Solutions.
According to Paul Mihm, executive vice president, technical services group, Rubicon, ASHRAE's 2008 standards are being adopted by some data centers, while others prefer the perceived safer environment of much cooler temperatures. "In the co-location industry, they are trying to get their leases revised to 2008 standards," Mihm says. "The old standards are too stringent, and they receive a financial penalty when they exceed those parameters." Co-location leases with clients include service-level agreements that specify financial penalties for the data center if agreed-upon levels of temperature and humidity are exceeded.
Some data centers are running at only slightly higher temperatures, says Mihm. "People have a difficult time embracing aggressive elevated temperatures to save cooling costs because the time to reach critical temperature is significantly shorter in the event of a failure," he says. "A significant mechanical cooling failure, where the temperature goes to 104 F or 108 F, will take you out of business."
Much of the resistance to higher operating temperatures comes from enterprise data centers such as banks, insurance companies, and other financial businesses, where an equipment malfunction resulting in down time or data loss has catastrophic consequences. Even when a risk-averse company opens a new data center or buys new equipment, they will still run a much cooler operation, where the incoming air to the cabinet is 70 degrees, says Voss. "Their view is that they can never go down," he says.
Where synchronous data backup exists, there is less of a risk, but even in those instances, the operations manager of an enterprise center may not want to chance a meltdown. "If the entire management embraces the idea [of higher temperatures], and the change is clearly managed and accepted, it will be a good opportunity to save revenue," Mihm says.