In 2010, green data center designers hit a point of desperation. Server rooms were already struggling to earn LEED points because of their high energy-use and unique design, then ASHRAE and LEED revoked exemptions that excluded data centers from models of building energy cost. Data centers now had to meet the same energy-efficiency standards as any other commercial project, despite having greater power supply and cooling needs.
“Everyone started to throw their hands up in the air and say, ‘Why try?’” says Bill Kosik, director of energy and sustainability at Hewlett Packard’s Critical Facilities Services, which designs data centers for private clients. “Because data centers are often dark and remotely located, we couldn’t earn many of the daylight and quality transit points available to other buildings.”
This past November, the USGBC hoped to resolve the controversy by publishing new industry-specific compliance options for data centers. LEED V4 offers credits for the use of energy-efficient servers, power supplies, and cooling systems, and commissioners will be asked to review data center plans during construction and design. LEED V4 also clarifies the scope of Daylight and Thermal Comfort credits by explicitly allowing regularly occupied spaces inside a data center to earn points for the whole facility. So even if the computer room itself is too hot and dark to meet the credits, the office space adjacent to the server room can.
“It’s always been a mixed bag for data centers—they have had the benefit of being excluded and the difficulty of meeting standards,” says Corey Enck, director of LEED technical development for the USGBC. “Now that we have seen so much growth in the IT market, there is a real need to adapt standards to take data centers into consideration.”
In the 1999 version of ASHRAE, data centers were not regulated by ASHRAE standard 90.1, which has the criteria referenced by LEED. This meant that LEED buildings also excluded data centers and server rooms as unregulated energy loads. This changed in 2010 when ASHRAE revised language to include data centers in whole-building energy calculations and drafted energy efficiency requirements for data centers.
The new standards inspired some of the most innovative buildings in the world. To cut cooling costs, data centers began to actively harness outdoor resources like wind and winter frosts. This contrasted with the insulated data centers of the past, which were constructed in the heart of a building to control exposure to humidity.
A group of students tour the LEED Platinum, solar-powered data center built for the National Renewable Energy Laboratory.
In 2010, Hewlett Packard opened a building in Newcastle, United Kingdom, that uses seven-foot fans to pull cool ocean breezes into a duct system that spans the entire lower floor of the building. That same year, the National Renewable Energy Laboratory (NREL) opened a data center in the Denver area that runs entirely on solar power. The LEED Platinum building pulls cool air from outside into a labyrinth of large cement ducts in the basement. And in 2012, Facebook implemented a similar design in its Prineville, Oregon, data center that earned LEED Gold certification. The building pulls in cool air from outside, evaporates water into the air to achieve further cooling, and then channels the chilled air to server rooms.
These buildings have one thing in common—a system called an economizer that uses outdoor air to cool server racks. As of 2010, economizers were used in the baseline comparative models outlined in ASHRAE standard 90.1 Appendix G. LEED has always referenced ASHRAE, but LEED V4 is the first to reference the controversial 2010 standard that makes economizers a necessity. “According to the new standards you don’t have to use an economizer, but if you don’t, you have to make up for it by saving a lot of energy in some other way,” Enck says. “I haven’t seen any examples of people meeting the standard without an economizer, although this might change.”
To include an economizer in an exisiting data center, the building would have to be renovated to make room for innovative ductwork and custom evaporative systems, and some designers worry that economizers won’t work in hot desert climates or in big cities where pollution contaminates outside air. “There was a real standoff over this—the problem is that not all projects can bring in outside air, and sometimes dust and pollutants can damage machines,” says Ron Jarnagin of ASHRAE.
In response to industry concerns that economizers are too expensive and constraining, Jarnagin drafted a new standard for large data centers that use more than 20 watts per square foot of energy. At the time of writing, ASHRAE standard 90.4 was set to go into effect late 2013 and will not likely require economization; economizers will instead be part of an alternative compliance pathway.
Since 2010, 82 data centers have earned LEED certification; Kosik helped design 30 of the 82, and he asserts that economization is the best practice to reduce energy use. In a data center, the servers alone can account for 60 to 70 percent of a building’s energy use, and the cooling and electrical systems needed to maintain server performance to make up the remainder, which is why installing efficient light bulbs, solar panels, and better insulation hardly makes a dent.
Of the 82 projects, 12 received Platinum certification and 43 earned Gold. Many of these projects voluntarily used outdoor resources to cool air or water even though prior versions of LEED did not reference ASHRAE economizer criteria. Kosik says the changes to LEED and ASHRAE will help more data centers certify, but the final outcome is even more important. “After all the bugs are ironed out, data centers will have a true reduction of energy,” Kosik says. “The goal is not just to earn points and meet standards. The point is to encourage greater energy reductions.”
It’s too early to say whether the standards will encourage widespread reform within the industry, but at the very least, the new criteria will help data centers save a lot of money. “There is a really good business case for energy reductions,” says Enck. “Data centers see a significant return on their investment when they incorporate energy-efficiency strategies, which is what the new standards encourage.”
