ATLANTA — Because high plug loads and rapidly advancing IT technology make data centers significantly different from commercial buildings, a purposed standard from ASHRAE that specifically addresses the energy requirements of data centers is now open for advisory public review.

Standard 90.4P, Energy Standard for Data Centers and Telecommunications Buildings, is being developed in response to requests to recognize the energy performance profiles unique to data centers; previously, data centers were included in ANSI/ASHRAE/IES Standard 90.1-2013, Energy Standard for Buildings Except Low-Rise Residential Buildings. Standard 90.4P will feature a performance-based approach that is more flexible and accommodating of changes which rapidly occur in data center design, construction, and operations, according to chair Ron Jarnagin.

“The explicit needs of data centers drive a fundamentally different approach to regulating minimum efficiency requirements for the electrical and mechanical systems that support the plug loads,” said Jarnagin. “By using an approach that requires compliance to a ‘system’ level of performance, designers and end-users can utilize various trade-offs in their optimization strategies depending on their company-specific business models.”

Also, current industry modeling tools do not possess all the necessary mathematical models to accurately and appropriately model data center HVAC and power design. As a result, demonstrating compliance to the 90.1 Chapter 11 or energy cost budget approaches is not always a practical option. Instead, Standard 90.4P proposes to utilize a performance compliance path known as power utilization efficiency (PUE) developed by The Green Grid®.

Although there is proposed research for the development of mathematical methods and associated software tools to assist data center designers down the road, compliance with 90.4P is intended to be possible without the use of modeling tools at this time.

Standard 90.4P is open for advisory public review until Dec. 30, 2013. For more information, visit

Publication date: 12/9/2013

Want more HVAC industry news and information? Join The NEWS on Facebook, Twitter, and LinkedIn today!