ATLANTA — ASHRAE has announced the latest edition of the principal book in its Datacom Series of publications, which includes four new data center classes that can enable fulltime economizers for a number of applications in many climates.

ASHRAE said that Thermal Guidelines for Data Processing Environments, published by its Technical Committee (TC) 9.9, Mission Critical Facilities, Technology Spaces and Electronic Equipment, provides a reference for unbiased and vendor-neutral information on design and operational parameters for the datacom (data centers and telecommunications) industry.

Based on the latest information from major IT equipment manufacturers, which are part of the committee, the book supplies guidance to data center designers and operations staff to design and run their facilities in the most energy efficient manner possible, including how to operate in a “chilllerless” environment. In addition, the guidance enables a more energy efficient operation without compromising the reliability of the data center.

“This third edition creates more opportunities to reduce energy and water consumption but it is important to provide this information in a manner that empowers the ultimate decision makers with regards to their overall strategy and approach,” said Don Beaty, chair of the Publications Subcommittee of TC 9.9. “The idea is to provide objective data, methodology, and guidance, but at the same time, respect the right of the data center designers, owners, and operators to optimize the operating environment of their data center based on the criteria most important to their business needs.”

Highlights in this third edition include new air and liquid equipment classes and expanded thermal envelopes for facilities that are willing to explore the tradeoffs associated with the additional energy saving of the cooling system through increased economizer usage and what that means in terms of the impact to IT equipment attributes such as reliability, internal energy, cost, performance, contamination, etc.

“The most valuable update to this edition is the inclusion of IT equipment failure rate estimates based on inlet air temperature,” Beaty said. “These server failure rates are the result of the major IT original equipment manufacturers (OEM) evaluating field data, such as warranty returns, as well as component reliability data. This data will allow data center operators to weigh the potential reliability consequences of operating in various environmental conditions vs. the cost and energy consequences.”

The cost of Thermal Guidelines for Data Processing Environments, third edition, is $54 ($46, ASHRAE members). To order, contact ASHRAE Customer Contact Center at 800-527-4723 (United States and Canada) or 404-636-8400 (worldwide), fax 404-321-5478, or visit

Publication date: 10/22/2012