STULZ Air Technology Systems, Inc. (STULZ USA) has announced the publication of a new white paper titled, “Regulations Determining Computer Room Cooling Selection - Precision vs Comfort Cooling.” This white paper is intended to assist engineers and contractors who are designing data centers and small IT spaces by providing a history of the various requirements for computer room cooling, along with a detailed overview of the most recent federal regulations.

“There is no shortage of misinformation defining the appropriate use of air conditioning equipment for computer room applications,” said Dave Meadows, director of industry, standards, and technology, STULZ, and the white paper’s author. “The regulatory landscape has changed significantly over the past few years, and we hope to make sense of it all for the engineers and contractors who are facing increasing concern about correctly applying HVAC equipment to computer rooms.”

Prior to 2010 there was no minimum required energy efficiency for computer room cooling equipment in the United States. But with data centers estimated to consume over 3% of the total US power output, the US Department of Energy (D.O.E.) has sought to reduce power usage, and compel the industry to comply with guidelines from the American Society of Refrigeration Engineers (ASHRAE). Today, federal regulations require computer room cooling equipment to meet a minimum Sensible Coefficient of Performance (SCOP) while similar municipal and state conservation codes are continuously evolving. 

“These are fast changing requirements and many engineers and end users are inadvertently misapplying comfort cooling units in computer rooms simply because they are not aware of the benefits of  application specific units or the regulatory aspects of the application,” continued Meadows. “CRAC manufacturers have dedicated thousands of hours of research and development in an effort to create the most energy efficient equipment for this particular application. Comfort cooling equipment has neither the tight control, robust design, nor the built in energy efficiency required to serve the computer room adequately. Specifying or installing the wrong equipment can be costly in both lost energy efficiency and potential fines for non-compliance.”

To date, the Department of Energy (D.O.E.) has not exempted any state from this energy efficiency standard.

According to the white paper, a major impact of the D.O.E.’s decision to add computer room air conditioners to its list of federally regulated appliances is the classification of “computer rooms." Among other things, a computer room is defined as any room which has a design electronic data equipment power density exceeding 20 watts per square foot of conditioned floor space. This low threshold has resulted in relatively small IT spaces and office server rooms being subject to minimum SCOP requirements for HVAC equipment.

“With this white paper, it is our hope that we can provide a very useful resource for engineers and contractors designing computer room spaces of all sizes,” concluded Meadows. “While it is not a replacement for studying the applicable federal, state, and local building codes, I believe most readers will find it helpful and informative.”

The complete white paper can be downloaded here.