Computers are power-intensive devices, meaning a great deal of electricity is required to power small equipment. An enterprise data center may contain hundreds, if not thousands of pieces of IT equipment, all using lots of energy and therefore generating lots of extra heat.
The traditional approach to keeping data centers cool has been to apply brute force and cool the environment to meat-locker temperatures (another energy-intensive process).
However, these chilly standards aren’t necessary if good air management practices are in place. Bill Kosik, principal and green business technology lead at HP Critical Facilities Services, says that data center equipment performs well and without failure at higher temperatures than previously thought.
“Based on new research data, industry organizations such as the American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) have relaxed operating temperature and humidity requirements,” says Kosik. “This is very important from an energy use and environmental standpoint. Raising the air temperature from 60°F (16°C) to 70°F (21°C) could reduce energy use of the cooling systems by 20 percent.”
The real trick though, says Kosik, is in equalizing the overall temperature of the data center. That means identifying and eliminating hot spots and redistributing cool air more evenly by optimizing use of your AC equipment.
Many data centers continually run air conditioning (AC) units at full capacity. On top of that, many also run back-up AC units full time, just in case.
“Most AC units running at full speed are blowing more air than is necessary,” explains Kosik. “Reducing the speed of your fans by 25 percent can reduce that unit’s energy consumption by up to 60 percent.”
According to Kosik, AC units running at full capacity should focus on areas that create the most heat. But you must also identify the cool spots that require less air flow and reduce fan speeds in those areas.
As an additional step, Kosik recommends, turn off your redundant AC units and let them do what they’re supposed to do—serve as back-up in case primary units fail or temperatures rise too high. But be sure to conduct thorough maintenance of AC equipment on a regular basis, and test control systems to verify that they’ll properly react to anticipated failure scenarios.
Humidity is the third culprit in the data center power binge. Servers and storage equipment need just enough moisture in the air to prevent electrostatic discharge. Yet too much moisture causes erosion and can shorten the equipment’s lifespan. Maintaining this narrow, optimal range of humidity typically requires energy-sucking humidifiers.
However, similar to misperceptions about data center air temperatures, an acceptable range of humidity may actually be broader, especially if overall air temperatures can increase.
“The standard humidity tolerance level for data centers was previously stated at 40 to 55 percent,” says Kosik. “But we’re seeing that most equipment can tolerate a wider range, more like 30 to 60 percent, depending on the temperature.” This means data centers don’t have to exert as much energy trying to maintain a narrow, optimal range of humidity.
As welcome as these new findings on temperature may be, Kosik also cites the need for further investigation. Kosik advises companies to proceed cautiously and to conduct thorough analysis before adopting new heat and humidity tolerance standards.
With the acquisition of EYP Mission Critical Facilities, HP filled an important niche in its data center services portfolio and greatly expanded its expertise in energy efficiency. Now HP Critical Facilities Services offers a range of services to address data center planning, design and operations issues.
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