How to design data centers: Codes and standards

An expert panel provides engineering and design tips in this Q&A, including information about codes and standards

By Consulting-Specifying Engineer April 29, 2021


  • Peter Czerwinski, PE, Uptime ATD, Mechanical Engineer/Mission Critical Technologist, Jacobs, Pittsburgh
  • Garr Di Salvo, PE, LEED AP, Associate Principal – Americas Data Center Leader, Arup, New York
  • Scott Gatewood, PE, Electrical Engineer/Project Manager, Regional Energy Sector Leader, DLR Group, Omaha, Neb.
  • Brian Rener, PE, LEED AP, Mission Critical Leader, SmithGroup, Chicago

Please explain some of the codes, standards and guidelines you commonly use during the project’s design process. Which codes/standards should engineers be most aware of?

Garr Di Salvo: In the U.S., the IBC, NFPA 70: National Electrical Code and, in most jurisdictions, IFC, IPC, IMC, form the principal basis of local requirements. Some of these have include sections that have unique especially pertinent to data center projects, (like NEC Articles 645 and 685, which outline requirements for facility emergency power off EPO). Additional standards include NFPA 70E, 110 and 111, IEEE 493 and 1584, ASHRAE Fundamentals, Datacom 1 and 90.4. Organizations like FM Global, UL, NETA and SMACNA also provide important guidelines for data center designers.

Peter Czerwinski: The prevailing energy conservation code is one of the most important codes a data center designer must be aware of. Certain equipment capacities in certain climate zones require economizers, so if a data center owner is retrofitting the building with what was thought to be a quick, inexpensive fix, it is important to check the local codes for requirements that may not be obvious.

How has ASHRAE Standard 90.4-2019: Energy Standard for Data Centers affected your work?

Garr Di Salvo: While power usage effectiveness is intuitive, it can be quite difficult to measure in an existing facility where metering is limited. Moreover, it only represents a “an instantaneous assessment snapshot” of energy consumption. It does not capture, without consideration for variations based on time of day, season or climate and, without which it can be difficult to garner provides little insight into the nature of what’s causing energy losses or and identify opportunities for improvement.

ASHRAE Standard 90.4 offers a reasoned methodology for evaluating data center efficiency that accounts for these concerns. As such, it provides insights that can be and is more readily applied in design, during the design process, when choices can have the greatest impact. It provides a “language” for discussion of facility efficiency that can push the industry forward in the same way that the Uptime Institute advanced discussion of data center reliability.

What are some best practices to ensure that such buildings meet and exceed codes and standards?

Garr Di Salvo: Arup has developed training for our staff training modules to help ensure that those working on data center projects are knowledgeable of both ensure that all staff working on data center projects are well versed in the applicable codes and up to speed on current best practices. applicable to their design. Maximizing efficiency within the data center is a key design consideration as this helps both the meet code requirements but also minimize operational cost to the operator. Reduction of power associated with HVAC has been a goal for data centers for a long time and by taking advantage of the full allowable temperature range of ASHRAE, raising the supply temperature of the facility and through optimization of HVAC systems through computational fluid dynamics analysis significant improvement in overall energy efficiency can be gained.

In addition, providing scalable solutions for the fit out of data centers helps to both minimize Day One capital costs and also the associated energy cost in operating the facility. Maximizing the use of installed equipment increases the overall efficiency of the facility.

What are some of the biggest challenges when considering code compliance and designing or working with existing buildings?

Garr Di Salvo: Equipment spaces may have been designed under previous versions of codes and assuming the use of older technology. One example is the use of flooded-cell or valve regulated lead acid batteries in uninterruptible power supply systems versus lithium-ion batteries, which are becoming more commonplace.