FOCUS COOLING UPDATE
Issue 11, Aug/Sept
REQUIREMENTS IN 90.1 STANDARD Engineer says lowering PUE is small price to pay for slowing climate change
Refrigeration and Air Conditioning Engineers (ASHRAE).
I
The standard deals with the energy efficiency of buildings, and part of the update process is to fold data centers under its purview.
In response to a draft of changes addressing data centers, data center executives from some of the most prominent companies in the industry, including Google, Digital Realty Trust, Microsoft and Amazon, co-signed a letter protesting its “prescriptive” approach to energy efficiency. The letter said efficiency assessments should be based on performance rather than design.
One of ASHRAE’s members involved in the future standard responded to the letter in a presentation at DatacenterDynamics San Francisco in July. Mark Hydeman, a principal at Taylor Engineering and vice chairman of an ASHRAE committee dealing with the future standard, clarified where ASHRAE stood and answered some of the questions the controversy had generated.
Hydeman emphasized that there would be a performance-based way to meet efficiency requirements in the standard – the letter’s main contention. The method entails showing that the facility is just as energy efficient, or more energy efficient, than a facility that fulfills all the prescriptive requirements.
Requirements for data centers listed in the last draft have been voted for publication, Hydeman said. The only way they can still be prevented from being published is by appeal. As of mid July, no appeal had been filed.
Hydeman reminded his audience why ASHRAE was revising the standard to require 30% more energy efficiency than the existing 2004 version. The reason was climate change – and the need to stop it.
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www.datacenterdynamics.com
n the last issue of FOCUS, we explored the controversy that had been brewing around the process of updating Standard 90.1 of the American Society of Heating,
“It’s not a big step to go from [PUE] 2.0 to 1.5. And when you do that, power plants get decommissioned or are not being built,” he said. “We have a problem, and we all know it – that’s why we’re doing energy efficiency in data centers.”
US AUDIT HIGHLIGHTS BEST PRACTICE FLAWS
The US federal government’s data center consolidation push has been well publicized. A recent report on an energy efficiency audit of four data centers of one federal agency shows that the Obama administration’s concern is not baseless.
A review of the cooling setup in four data centers of the Internal Revenue Service, conducted by the Treasury Inspector General for Tax Administration, revealed substantial inefficiencies that could easily be eliminated by following existing industry best practices.
Facilities in Memphis, Tennessee; Martinsburg, West Virginia; Austin, Texas; and Ogden, Utah, were reviewed between June 2009 and January 2010.
Reviewers found missing floor tiles in the raised floor, allowing cold and hot air to mix, resulting in inefficient use of CRAC units.
In some instances, perforated tiles – placed ad hoc around the computer floor – were cooling hot aisles. This pattern was observed in Martinsburg, Memphis and Ogden.
The same three facilities either did not use – Current Site Site ECC - Memphis
ECC - Martinsburg Ogden Campus Austin Campus
Energy Use-DCiE 0.66
0.71 0.72 0.79
ASHRAE’S HYDEMAN DEFENDS DATA CENTER
or used inconsistently – brush grommets and blanking panels to seal air leaks in the floor and in equipment racks.
Servers in the three data centers were not all properly arranged to separate cold and hot aisles, with each facility having at least one rack aligned so that servers returned hot air into the cold aisle. Servers in the three locations also weren’t placed in rows consistently, with some spread around the room ad hoc.
In all four facilities, spacing between server rows was inconsistent, ranging between four and 14 feet.
The data centers also contained a lot of unused furniture, computers and that other equipment stored on computer floors which obstructed the air flow.
The Martinsburg and Memphis data centers had an abundance of unused space. If condensed the Martinsburg facility, for example, had three server areas, with only half of the space used in each of them. Had the computer rooms been consolidated, the facility would have required much less cooling.
The report pointed to a 2006 energy audit of the Martinsburg data center, which said the facility had 10 times the amount of air conditioning capacity required.
The audit focused largely on cooling in the four data centers, but also mentioned a lack of motion detectors to control inside lighting, as well as a lack of sub-metering to monitor power consumption.
Potential Site Efficiency
Energy Use-DCiE Measure Change 0.88
0.90 0.90 0.85
0.22 0.19 0.18 0.06
Source: Data Center Energy Profiler tool completed by the IRS June 2009 to January 2010
Percentage Change
33.33% 26.76% 25.00% 7.59%
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