Analyzing data centers: codes and standards

Data is the lifeblood of any business or organization—which makes a data center a facility’s beating heart. Here, engineers with experience on data center projects show how to succeed on such facilities, and how to keep your finger on the pulse of data center trends in regards to codes and standards.

By Consulting-Specifying Engineer April 27, 2017


  • Robert C. Eichelman, PE, LEED AP, ATD, DCEP, Technical Director, EYP Architecture and Engineering, Albany, N.Y.
  • Karl Fenstermaker, PE, Principal Engineer, Southland Engineering, Portland, Ore.
  • Bill Kosik, PE, CEM, LEED AP, BEMP, Senior Mechanical Engineer, exp , Chicago
  • Kenneth Kutsmeda, PE, LEED AP, Engineering Manager—Mission Critical, Jacobs, Philadelphia
  • Keith Lane, PE, RCDD, NTS, LC, LEED AP BD&C, President, Lane Coburn & Associates LLC, Bothell, Wash.
  • Brian Rener, PE, LEED AP, Senior Electrical Engineer, SmithGroupJJR, Chicago
  • Mark Suski, SET, CFPS, Associate Director, JENSEN HUGHES, Lincolnshire, Ill.
  • Saahil Tumber, PE, HBDP, LEED AP, Senior Associate, Environmental Systems Design, Chicago
  • John Yoon, PE, LEED AP, Lead Electrical Engineer, McGuire Engineers Inc., Chicago

CSE: Please explain some of the codes, standards, and guidelines you use during the design process. Which codes/standards should engineers be most aware of in their design of engineered systems in data centers?

Mark Suski: Key codes and standards being used today are NFPA 72: National Fire Alarm and Signaling Code, NFPA 75: Standard for the Fire Protection of Information Technology Equipment, NFPA 70: National Electric Code (NEC), and NFPA 2001: Standard on Clean Agent Fire Extinguishing Systems. Plus, large companies will have internal corporate-protection requirements for their data centers. There are two methods to provide fire protection within the data center, the first is the prescriptive-based approach and the second is a fire-risk-based approach. The prescriptive-based approach involves reviewing the appropriate code and/or standard and installing the required detection and suppression systems. This method does not take into account any site-specific issues and can be considered a one-size-fits-all approach. The risk-based approach allows the user to evaluate how critical the equipment is, assess the importance of equipment operation, and factor in business continuity if the equipment is out of service to determine the level of protection needed. The information gathered during the risk evaluation is reviewed against potential protection strategies to determine the best course of action for the specific data center. This is a more tailored approach and provides the appropriate level of protection for the individual site.

Tumber: The commercial design and construction codes are typically applicable to data centers. Due to their unique requirements, it is important to implement the codes creatively to meet the data center needs—specifically, the energy codes, such as International Energy Conservation Code (IECC)  and ASHRAE Standard 90.1: Energy Standard for Buildings Except Low-Rise Residential Buildings. There are also a number of publications from the Department of Energy (DOE) and ASHRAE (e.g., ASHRAE Standard 90.4: Energy Standard for Data Centers and TC 9.9: Mission Critical Facilities, Data Centers, Technology Spaces and Electronic Equipment), U.S. Green Building Council (USGBC), U.S. Environmental Protection Agency (EPA), NFPA, The Green Grid, and others that provide pertinent information and guidelines for creating industry-leading data center designs.

Lane: NEC, NFPA 780: Standard for the Installation of Lighting Protection Systems, the Building Industry Consulting Service International standards, and the International Building Code are just a few of the standard codes that must be followed in data center design. It is critical to understand the client’s reliability and redundancy needs and to match those needs (or client standards) with the design. The engineer must understand the standards required to meet the reliability and concurrent maintainability as well as owner’s flexibility requirement.

Rener: NEC, NFPA 110: Standard for Emergency and Standby Power Systems, IEEE Recommended Practices for the Design of Reliable Industrial and Commercial Power Systems (IEEE Gold Book), The Green Grid, Uptime Institute, and ASHRAE 90.1 are codes and standards that are most commonly used in data center design.

Kosik: The first thing an engineer needs to do is research the pertinent codes and standards that are required by the local authority having jurisdiction (AHJ)—and not just the explicit codes and standards, but all of the referenced codes and standards. This full review may uncover any additional information that will inform the design, and maybe in ways the engineer hasn’t anticipated. I have found that generally all of the required information is contained in all of the code documentation, but occasionally I have come across a piece of data in the referenced documents that would be problematic if not addressed. In terms of design standards and guidelines, ASHRAE is the primary source. They have a great DataCom series that covers a wide range of design-related topics for data centers. Another excellent publication is the Data Center Handbook, published in 2014. It is a very information-rich book on pretty much any topic related to data centers.

Eichelman: There are several standards written specifically for data centers. These include NFPA 75, NEC articles 645 and 708, Uptime Institute Data Center Site Infrastructure Tier Standard Topology, TIA 942, USGBC LEED v4, and ASHRAE Standard 90.1. NFPA and ASHRAE standards are typically, but not always, referenced directly by the applicable building code for a project, but are considered best practices nonetheless. Uptime, TIA, and USGBC standards offer best practices depending on the nature, reliability requirements, and energy efficiency goals of the facility. Executive Order EO13693 includes specific requirements related to energy consumption for all existing and new federal data centers.

CSE: How do you anticipate ASHRAE 90.4 will impact the design process? 

Rener: ASHRAE 90.4 is a performance-based standard versus a prescriptive-based standard like ASHRAE 90.1. This gives the design team more flexibility in the system design approach to meet the goals of the document, such as not forcing an outside-air economizer design, with which some operators are uncomfortable. ASHRAE 90.4 also addresses data center system renovations in a manner that does not require making major upgrades to legacy MEP systems to be in compliance during a small renovation. Currently, design efficiencies are usually modeled with a PUE value, but this ratio of efficiency was intended to be a measured value of actual performance, not predicted performance. The calculations for ASHRAE Standard 90.4 may start to replace the PUE prediction in the design phase.

Yoon: While data center efficiency/energy consumption has always been a concern because of its impact on operational costs, its importance has always been a distant second to ensuring uptime. ASHRAE 90.4 was written as a logical extension of ASHRAE 90.1. While it’s unclear if or when ASHRAE 90.4 will be adopted by AHJs, this code has the potential to change that.

Tumber: The commercial energy codes, such as IECC and ASHRAE 90.1, do not adequately encompass data centers due to their unique requirements. ASHRAE 90.4 is performance-based and is a step in the right direction. It will aid with the compliance process once AHJs start adopting the standard, and there is harmony with ASHRAE 90.1. It will also help in benchmarking and comparing alternate designs from an energy efficiency perspective. Meeting the requirements of ASHRAE 90.4 should not be difficult, as we have been designing data centers that exceed the minimum requirements listed in it.

Kosik: ASHRAE 90.4 is a document that most of the data center design professionals have been asking for over the past 10 years. The data center design community has become much more sophisticated as organizations such as The Green Grid have been formed, the DOE’s Center of Expertise for Energy Efficient Data Centers, and other international standards, such as BREEAM and Infocomm Development Authority of Singapore’s Green Data Centre Innovation Programme (GDCIP). I consider ASHRAE 90.4 to be a robust augmentation of ASHRAE 90.1. It fills in the gaps in determining how to calculate and develop baseline energy models for data centers, which are very different in electrical density, usage, and energy consumption. Like any new standard, it will have some areas that need improvement or further refinement, but it is certainly an important standard in the world of data centers.

CSE: How are codes, standards, or guidelines for energy efficiency impacting the design of such buildings?

Lane: As the expectations of lower energy use and lower PUE continue to increase, significant coordination between electrical engineers, mechanical engineers, and the architect is required. Selection of efficient electrical equipment as well as HVAC system design, and most significantly, air containment and pathways require coordination with all design entities.

CSE: How will the 2017 edition of NEC impact building design? What are the challenges/solutions?

Yoon: One of the biggest changes is the inclusion of a new article, 706 Energy Storage Systems. Although it is geared toward distributed energy storage for PV and wind generation, the way that it’s written makes it applicable to UPS applications. Unlike other sections, Article 706 in the 2017 edition doesn’t yet have much in the way of commentary to help explain intent or how it will evolve in future editions of the NEC.

Rener: There are some expanded requirements for labeling available short-circuit levels and ratings at some equipment including HVAC controllers. The biggest changes are related to the expanding green and alternative energy sources, which are finding increased use in data centers. Article 690 includes requirements for “rapid shutdown” controls for solar systems, highlighting a concern data center users have had in the past for emergency power-off devices for generators and UPS systems. In addition, several brand-new articles have been introduced including Article 706 Emergency Storage Systems, Article 710 Stand Alone Power