Latest from Air Conditioning
Johnson Controls-Hitachi Air Conditioning
American Society of Heating Refrigeration and Air Conditioning Engineers Logo

ASHRAE Adds Supply-Water-Temp Class to Data-Center-Cooling Guidance

April 22, 2014
“There is an increasing interest in liquid-cooled IT equipment at the rack, equipment, and component levels,” Don Beaty of ASHRAE TC 9.9 said.

ASHRAE recently announced the publication of the second edition of “Liquid Cooling Guidelines for Datacom Equipment Centers.”

“There is an increasing interest in liquid-cooled IT (information technology) equipment at the rack, equipment, and component levels,” Don Beaty, publication chair of ASHRAE Technical Committee 9.9, Mission Critical Facilities, Data Centers, Technology Spaces and Electronic Equipment, which authored the book, said. “There is also increased interest in reuse of the heat rejected from IT equipment. One of the more important changes to the second edition is the addition of supply-water-temperature classification.”

Beaty said the addition of liquid classes can have an effect on the industry similar to the creation of supply-air-temperature classes, which was the critical enabler to the use of economizers in data centers.

“There are five water-temperature classes, with the highest temperature class being greater than 45°C (113°F), which opens up possibilities for using the rejected heat for building heating systems,” Beaty said.

The book provides guidance related to interfaces between chilled-water and technology-cooling systems and discusses liquid-cooled systems that attach to a datacom electronics rack to aid thermal management.

Also included are updated references and information on approach temperatures and liquid-immersion cooling and guidance related to water-quality problems and wetted-material requirements.

Additionally, the guide defines liquid and air cooling in the context of IT equipment and provides an overview of chilled- and condenser-water systems and other datacom-equipment cooling options.

The cost of the second edition of “Liquid Cooling Guidelines for Datacom Equipment Centers” is $46 for ASHRAE members and $54 for non-members. Copies can be ordered by phone at 800-527-4723 (United States and Canada) or 404-636-8400, by fax at 678-539-2129, or online at

About the Author

Scott Arnold | Executive Editor

Described by a colleague as "a cyborg ... requir(ing) virtually no sleep, no time off, and bland nourishment that can be consumed while at his desk" who was sent "back from the future not to terminate anyone, but with the prime directive 'to edit dry technical copy' in order to save the world at a later date," Scott Arnold joined the editorial staff of HPAC Engineering in 1999. Prior to that, he worked as an editor for daily newspapers and a specialty-publications company. He has a bachelor's degree in journalism from Kent State University.