ZURICH - Since 2008, the largest players in the data center industry have been advocating operating server rooms at warmer temperatures. Google, Yahoo, Microsoft and Facebook have all embraced the idea of raising the thermostat in their data centers, saying the benefits of reduced spending on cooling can be substantial, and the practice hasn't led to elevated hardware failures.
But few enterprise data centers are following suit, according to Zahl Limbuwala, chairman of the Data Center Specialist Group at BCS, the leading IT industry group in the UK.
"We're still stuck at low temperature points," said Zimbuwala, who gave a presentation at the Google European Data Center Efficiency Summit Tuesday in Zurich, Switzerland. "All the work the industry has done on this issue still needs to roll through. It really hasn't had the impact we thought it might."
Data Centers Weigh Risk vs. Reward
Most data centers operate in a temperature range between 68 and 72 degrees F (20 to 22 degrees C), and some are as cold as 55 degrees F (!2 degrees C). But Google and others have increased the data center temperature to 80 degrees F (about 27 degrees C).
Raising the baseline temperature inside the data center – known as a set point - can save money spent on air conditioning. By some estimates, data center managers can save 4 percent in energy costs for every degree of upward change in the set point. But nudging the thermostat higher may also leave less time to recover from a cooling failure, and is only appropriate for companies with a strong understanding of the cooling conditions in their facility.
The leading U.S. industry group for heating and cooling professionals, ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) increased its recommended operating range for data centers from 77 degrees to 81 degrees in a 2008 update.
Limbuwala reviewed data from a survey of BCS data center operators, which found that the majority of data centers continue to operate at 22 degrees C (72 degrees), with most of the remainder between 20 and 24 degrees C.
ASHRAE has just released new, expanded guidelines for server rooms based on the type of equipment and application, and the level of control the operator has over the environment. For data centers running mission-critical operations, ASHRAE has maintained the 2008 upper range of 80.6 degrees. It has also created several new categories for operators of data centers who have strong control over the environment and manage reliability using groups of networked data centers, such as Google or Microsoft or Yahoo. The upper range for those facilities can now range as high as 113 degrees F (45 degrees C).
Impact on Legacy Facilities and Equipment
The new guidelines draw clear distinctions between different types of facilities, according to Don Beaty, founder of DLB Associates and active member of ASHRAE Technical Committee 9.9. Beaty said many data centers covered by the ASHRAE guidelines are either older facilities or running legacy equipment that may not tolerate warmer environments as well as new equipment.
Harkeeret Singh of Thomson Reuters, who gave a presentation in Zurich on behalf of The Green Grid, emphasized the need for data center operators to be closely monitoring and managing conditions within their server rooms.
"Widening the temperature is more relevant for new data centers," said Singh. "We can't raise the temperature in the data center without dealing with airflow management. First do all the airflow management tasks, then raise the temperature."