Google Leads Opposition to Proposed ASHRAE Data Center Standard

April 14, 2010 by Jeff Shepard

The following letter was issued on the Google blog, expressing concerns regarding new efficiency requirements being proposed by The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) in its ASHRAE Standard 90.1 amendment.

The letter was singed by: Chris Crosby, Senior Vice President, Digital Realty Trust; Hossein Fateh, President and Chief Executive Officer, Dupont Fabros Technology; James Hamilton, Vice President and Distinguished Engineer, Amazon; Urs Hoelzle, Senior Vice President, Operations and Google Fellow, Google; Mike Manos, Vice President, Service Operations, Nokia; Kevin Timmons, General Manager, Datacenter Services, Microsoft.

"Recently, the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) added data centers to their building efficiency standard, ASHRAE Standard 90.1. This standard defines the energy efficiency for most types of buildings in America and is often incorporated into building codes across the country.

"Data centers are among the fastest-growing users of energy, according to an EPA report, and most data centers have historically been designed and operated without regard to energy efficiency. Thus, setting efficiency standards for data centers is important, and we welcome this step.

"We believe that for data centers, where the energy used to perform a function (e.g., cooling) is easily measured, efficiency standards should be performance-based, not prescriptive. In other words, the standard should set the required efficiency without prescribing the specific technologies to accomplish that goal.

That’s how many efficiency standards work; for example, fuel efficiency standards for cars specify how much gas a car can consume per mile of driving but not what engine to use. A performance-based standard for data centers can achieve the desired energy saving results while still enabling our industry to innovate and find new ways to improve our products.

"Unfortunately, the proposed ASHRAE standard is far too prescriptive. Instead of setting a required level of efficiency for the cooling system as a whole, the standard dictates which types of cooling methods must be used. For example, the standard requires data centers to use economizers � systems that use ambient air for cooling. In many cases, economizers are a great way to cool a data center (in fact, many of our companies’ data centers use them extensively), but simply requiring their use doesn’t guarantee an efficient system, and they may not be the best choice. Future cooling methods may achieve the same or better results without the use of economizers altogether. An efficiency standard should not prohibit such innovation.

"Thus, we believe that an overall data center-level cooling system efficiency standard needs to replace the proposed prescriptive approach to allow data center innovation to continue. The standard should set an aggressive target for the maximum amount of energy used by a data center for overhead functions like cooling. In fact, a similar approach is already being adopted in the industry. In a recent statement, data center industry leaders agreed that Power Usage Effectiveness (PUE) is the preferred metric for measuring data center efficiency. And the EPA Energy Star program already uses this method for data centers. As leaders in the data center industry, we are committed to aggressive energy efficiency improvements, but we need standards that let us continue to innovate while meeting (and, hopefully, exceeding) a baseline efficiency requirement set by the ASHRAE standard."

ASHRAE responded that the proposed changes would not force data center builders to use fresh air cooling in new facilities, but will leave room for companies to use other approaches. ASHRAE, in an e-mail statement, said the standard will include options for companies that opt for approaches other than economizers.

"The proposal to address data centers was made because a significant amount of energy is required to cool and ventilate computer rooms. Through this addendum, ASHRAE is proposing cost effective measures in the prescriptive path of Standard 90.1 to save energy in data centers. The addendum includes eight exceptions to requirements for the use of economizers in data centers. The addendum does not change the portion of the standard that already allows, through the Energy Cost Budget method (an alternate method of compliance), for data centers to be designed without economizers if other energy saving methodologies, including power usage effectiveness (PUE), are employed." ASHRAE said in its response.

Public comment on the proposed changes is open until April 19.