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For Release:
January 25, 2008

Contact:
Jodi Dunlop
Public Relations
678-539-1140
jdunlop@ashrae.org
1791 Tullie Circle NE
Atlanta, GA 30329

 

ATLANTA – Datacom center energy use is typically large and concentrated (it can be 100 times the watts per square foot of an office building), with operations running 24 hours, 7 days a week, about three times the annual operating hours of most commercial properties.

As a result, issues such as sustainable design, energy efficiency and operating cost become critically important for these facilities.

Guidance to assist those involved in the design, construction, commissioning, operation, implementation and maintenance of datacom equipment centers is available in a new book from ASHRAE, Best Practices for Datacom Facility Energy Efficiency.

“This book provides detailed information on the design of datacom facilities that will aid in minimizing life-cycle cost and maximizing energy efficiency,” said Tom Davidson. “The overall goal is to minimize total cost of ownership (TCO) for the end user, while helping to conserve energy resources on a global scale.”

Davidson is a member of ASHRAE’s technical committee on mission control facilities, technology spaces and electronic equipment, which wrote the book.

A study conducted by Lawrence Berkeley National Laboratory on average data center power allocation showed that only 46 percent of power was used by information technology (IT) equipment such as servers, while 23 percent was used by HVAC cooling equipment, 8 percent by HVAC fans, 8 percent by uninterruptible power supply equipment losses, and 4 percent by lighting.  Another 11 percent was attributed to other uses, such as miscellaneous electrical losses, support office area, etc.

“Since the infrastructure/energy cost is an increasing component of total cost of ownership, a strong emphasis must be placed on this cost to keep a datacom facility energy efficient and operating at the lowest cost to support the level of reliability and availability of the equipment it houses,” he said.

The book provides a listing of best practices in the areas of environmental criteria, mechanical equipment and systems, economizer cycles, airflow distribution, HVAC controls and energy management, electrical distribution equipment, datacom equipment efficiency, liquid cooling, total cost of ownership and emerging technologies. Examples of the best practices include:

Environmental Criteria

• Adoption of temperature and humidity ranges provided in ASHRAE’s Thermal Guidelines for Data Processing Environments publication can result in increased energy efficiency.

• For computer room air-conditioning equipment, focus the cooling solution on very high sensible/total cooling capacities per the revised ANSI/ASHRAE Standard 127-2007.

• Raising the supply air setpoint in a facility can significantly increase the number of cooling hours in economizer mode.

• Recognize that datacom equipment loads will change over the next 10 to 15 years. Develop a cooling distribution strategy that can adjust to these changes.

• Investigate the costs and benefits of different methods for humidity control. System design and control algorithms should allow the primary cooling coils to ‘run dry’ and thus allow for chilled-water reset at light loads without impacting relative humidity.

• Consider distributing high-voltage AC or DC power to point of use.

• Select power equipment from the highest input voltage available within its input voltage rating range.

• Consider the use of a cooling distribution unit (CDU) to isolate the liquid cooling loop from the building chilled-water cooling loop. This allows the liquid cooling loop temperature to be set above the room dew-point temperature, thus eliminating condensation.

• Use energy system modeling software to aid in developing an accurate TCO.

• Verify and document that the facility, its systems and assemblies are designed, installed and maintained in accordance with the owner’s program requirements.

ASHRAE, founded in 1894, is an international organization of some 50,000 persons. ASHRAE fulfills its mission of advancing heating, ventilation, air conditioning and refrigeration to serve humanity and promote a sustainable world through research, standards writing, publishing and continuing education.

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