ASHRAE Invites Industry Comment on Data Center Efficiency Standard Draft

ASHRAE, the body that creates standards for heating and cooling of buildings, has opened the comment period on the second draft of a new standard for data center energy efficiency.

ASHRAE doesn’t create building codes, but local and state officials in the US that do use its standards extensively. The data center standard’s first draft, announced in February, came under criticism by some in the data center industry for its use of PUE (Power Usage Effectiveness) to set efficiency benchmarks and generally for its prescriptive nature.

The standard, 90.4P, is meant to be used in tandem with a broader building energy standard, 90.1. An update to the latter drew similar industry criticism several years ago for favoring the use of economizers to achieve energy efficiency in data centers rather than making efficiency the goal in itself and leaving it to the data center operators to decide how to get there.

“Reviewers of this draft should understand that the Committee intended for this standard to allow innovation while still saving energy in data centers,” Ron Janagin, chairman of the ASHRAE 90.4 Committee, formed to create the new standard, said in a statement. “The Committee believes that it has recommended the requirements for PUE in the Standard based on a justifiable 80/20 rule where only the lower performing systems will be affected.”

One of the biggest changes in the second draft of 90.4P is removal of telecommunications facilities from its scope. A previous version would have applied to data centers and telco buildings. The current one covers data centers only.

The draft also revises data center, computer room, and telecommunications exchange definitions as well as paths to compliance with its PUE requirements.

The standard would apply to new data centers, expansions of existing data centers, and modifications of existing systems. In other words, facilities and systems already in place would not have to comply unless they are being changed in some way.

Here’s a digital copy of the second draft of ASHRAE Standard 90.4P.

You can comment on the draft here.

The second review period ends October 19.

A separate effort is also underway to expand ASHRAE's envelopes for humidity in data centers to allow for more use of free cooling.