Data center or telecom room?

By Tim Kuhlman, PE, RCDD, CH2M HILL, Portland, Ore. July 1, 2009

Capital costs and operating costs are two of the biggest concerns for building owners and operators. For new and retrofitted buildings, the capital cost of construction can determine whether a project can proceed or not. Whether a facility contains a large or small amount of technology equipment, the proper interpretation and application of the code is imperative to avoid inflating capital construction costs through the design and construction process. Article 645 of the National Electric Code (NEC) published by the NFPA, which addresses information technology (IT) equipment, is often misunderstood and misapplied.

Codes and regulations such as the NEC are adopted to protect people and property. This protection comes at a cost, but it is a necessary and required cost. However, when a code or regulation is applied to the wrong situation, it can add needless cost to the facility, which is then passed down to consumers. Not all equipment rooms with IT equipment fall under the definition of NEC 645. For the rooms that NEC 645 does address, the requirements of this article are not always needed.

Confusion in terms

To avoid these unnecessary costs, it is important to understand the definition of IT equipment in NEC 645. The NEC text refers to NFPA 75: Standard for the Protection of Information Technology Equipment in order to define the term “IT equipment.” NFPA 75 was authored by request of the computer industry for the standardization of fire protection recommendations. The term “IT equipment” was formerly defined as “electronic computer/data processing equipment” and “electronic computer system.” The terms “computer room” and “computer area” have been replaced by “IT equipment room.” In paragraph 3.3.10 of NFPA 75 , IT equipment is defined as “any electronic digital or analog computer, along with all peripheral, support, memory, programming, or other directly associated equipment, records, storage, and activities.”

Therefore, NEC 645 addresses computer rooms or data centers. To avoid confusion, for the remainder of this article the terms “IT room,” “computer room,” and “data center” have the same meaning and will be used interchangeably.

A common mistake in the communications industry is to apply NEC 645 to communication rooms that are used for networking, telephone equipment, and building cable distribution. Network hubs, routers, switches, gateways, and cable termination equipment are all used for IT, as defined by the communications industry. For the communications industry, the equipment and rooms are defined by Telecommunications Industry Assn./Electronic Industries Alliance (TIA/EIA) 568C.1: Commercial Building Telecommunications Cabling Standard and TIA/EIA 569B: Commercial Building Standard for Telecommunications Pathways and Spaces . Communication rooms are defined as “equipment rooms” or “telecommunication equipment rooms.” It is easy to see how the use of the term “IT equipment room” by NFPA 75 and TIA/EIA’s term of “telecommunication equipment room” can be confused to be the same. It is common in the trade to refer to telecommunication rooms as IT rooms as these rooms are often under the control of the IT department. However, the role and function of these two rooms are different, and confusing them can lead to higher construction cost.

The primary role of a computer room is to handle data processing and storage. The primary role of a communication room is to handle data transport. IT rooms may have communication (networking) equipment to handle internal data transport and to transport data outside the computer room. Likewise, occasionally IT equipment (file servers or control servers) is installed in a communication room. The presence of data processing or data transport equipment in a room does not change the primary role or definition of the room. As stated in NFPA 75 paragraph 1.3: Application, “The mere presence of the IT equipment shall not constitute the need to invoke the requirements of this [IT room] standard.” When a communication room is mistakenly built according to the IT room code, the building owner pays more than necessary to construct, maintain, and operate that room.

Another standard worth noting is TIA 942: Telecommunications Infrastructure Standard for Data Centers. The purpose of this standard is “to provide requirements and guidelines for the design and installation of a data center or computer room.” This standard also defines the terms for an “equipment room” or “equipment space.” It specifically identifies when the term “equipment room” applies to telecommunication by indicating it within a parenthetical. TIA 942 recognizes the difference in the role between an IT room and a communication room and attempts to delineate between the two to reduce confusion.


Code-mandated or provisional?

Chapters 1 through 4 of the NEC can be applied to most electrical applications within a facility. Chapter 6 addresses special conditions, which include Article 645 and the types of cables and wiring methods that can be applied to an IT room. A room falls under NEC 645 only if five special requirements are met. (See “Data centers, defined,” page 34.) If these requirements are not met, then the cabling requirements of Chapters 1 to 4 apply. Too often, people believe that the five requirements are required for any room that contains computer equipment, which is not the case. They are required only if the engineer wishes to apply other provisions in the article.

For example, NEC 645 allows certain types of cable to be installed under the raised floor of an IT room. In a traditional computer room, the space below the raised-access floor is an air plenum. For any other type of room built with the same type of floor and air-handling scheme, NEC 300.22(C) would be applied and the cable routed under the floor would have to be plenum-rated or routed in conduit. However, the NEC recognizes the special needs of a computer room, and NEC 645 permits non-plenum-rated cable, not installed in a raceway, to be routed through the under-floor plenum space.

Computers and code evolution

Computer room design evolves with the equipment that it supports. In a legacy data center that housed large mainframe computers and tape storage devices, the raised-access flooring was key in the distribution of cables between the equipment and the transport of cooling air and water. It was common for the manufacturer of the computing system to provide the data-transport cabling between the devices. These were proprietary cables for a proprietary computing system. The provisions for cabling that NEC 645 and NFPA 75 addressed made it easier to install proprietary cabling. This proprietary cabling would have been very costly to route in conduit or to manufacture custom plenum-rated cable.

Since the early 1960s when NFPA 75 was first drafted, there have been a lot of changes to the computing environment. In the past, the mainframe computer, associated periphery equipment, and its proprietary cabling took up most of the space in the computer room. Now, the primary occupants of the computer room are client server applications operating across file servers.

Data transport for computing also has evolved with standard technologies such as Fibre Channel and Ethernet. Standardized networking has led to standardized cabling for networks, and it is no longer necessary to get custom cabling from the computer manufacturer. With standard cable types, it is easier to get cables that are plenum-rated that can be routed exposed under a raised-access floor without building an NEC 645-compliant room.


A raised-access floor is no longer necessary for the distribution of cooling and cabling in a computer room. A raised floor can still be used, but there are methods for air and cable distribution that do not require it. A large portion of NEC 645 addresses the cabling for the space underneath raised-access flooring. If this is no longer required, then the article may not be applicable to the computer room. Likewise, the dedicated air-handling system for the room may not be applicable if there are no non-plenum-rated cables in the air plenum. A dedicated air-handling system still makes sense, but not for the sole purpose of isolating the provisional non-plenum-rated cable in an air plenum for code compliance.

The last revision of NFPA 75 was published in 2009. The conceptual computer room in Figure 2 is a traditional layout that may be considered antiquated. The current technology of high-performance servers, server density, and high heat loads may not work well in the computer room layout shown. The intention of NFPA 75 is to provide a standard for protecting IT equipment and the room. It may not apply to all computer room facilities, but the protection it intends to provide is still relevant even though the computing environment has changed.


Cash and consequences

A facility may choose to follow the recommendations of NFPA 75 even though it has not been codified by local jurisdiction. This is now a business decision even if it’s not a mandatory code requirement. Whereas the purpose of NEC is to provide practical safeguarding of people and property, NFPA 75 is focused on the protection of IT equipment. It is an evaluation of risk that a business must undertake in order to determine if it should adopt NFPA 75. (See “A risk management decision,” page 35.) If the proper precautions are not taken, building owners risk fire, life safety, or economic loss associated with the loss of function or equipment. For a healthcare facility, risk evaluation already may be determined by the industry that regulates the facility construction, or by corporate standards.

NFPA 75 recognizes that besides the risk to computing equipment, data, and the processing and storage of data, there are times when the transportation of data also is critical. A separate risk analysis is warranted to determine if this is the case. A hospital complex may have one or more computer rooms. The same facility may have 10 times as many communications rooms.

Case study: hospitals

Healthcare facilities are prime examples of IT/communications room confusion. Since IT serves such critical functions in healthcare settings, these rooms are very costly to construct. In a large facility like a hospital, computer rooms and communications rooms are often separate spaces. One exception would be for the network equipment area that directly supports a computer room, which may be within the computer room itself. Another exception would be for smaller facilities, such as clinics, that do not necessarily have the space to afford separate rooms for data processing and transport and will most likely combine these functions into a common space. If a healthcare facility is mislabeling its rooms and misapplying NEC 645, the extra costs are passed on to consumers, which may contribute to the high cost of healthcare.

Healthcare facilities are different from other facilities because of the services they provide. The building does more than protect people and property; the building systems are designed to support unique healthcare equipment and the ambulatory condition of occupants. Communication rooms may support equipment for access control, nurse call, paging, and intercom, and provide space for fire alarm panels. The presence of these systems may increase the regulatory requirements for communication rooms in healthcare facilities.

Additional code requirements and regulations would impact the design of a computer room or communication room. These codes would depend on the size, type, and jurisdiction in which the healthcare facility is located. NEC and NPFA have codes and standards specific to healthcare facilities, such as NEC 517 and NFPA 99. For example, if you are building or remodeling a facility in the state of California, then the Office of State Wide Health Planning and Development (OSHPD) standards need to be considered. OSHPD is one example of a local organization turning the provisional conditions of the code into mandatory requirements.

Critical communications

Not all data centers are the same. Some are large, purpose-built data centers that serve a region or corporation; some are small computer rooms for a local clinic. Computer rooms serve different functions, and each size and type has to be evaluated for risks of data and equipment loss. For instance, in healthcare facilities, not all computing requirements are critical for serving patients directly. The business side of healthcare that handles finances, billing, payroll, and other commercial operations relies on IT rooms as well, but there is not as much risk involved.

The Uptime Institute, in its white paper “Industry Standard Tier Classifications Define Site Infrastructure Performance,” provides guidelines for determining to what tier level a computer room should be built. The data center tier level will depend on the critical nature of information within the computer room and its susceptibility to disruption. With a thorough analysis of a proposed computer room, the construction and design cost can be minimized by not programming services, redundancy, and code applications where they are not needed.

NEC 645 is applicable to modern computer rooms. However, it may not be applicable for smaller rooms or very large purpose-built data centers that do not benefit from the provisions of the code. This depends on the critical nature of the room, a risk assessment of the data and equipment, and consideration for the impact on life safety.

Would it ever be necessary to build a communications room to the provisions outlined in NFPA 75 and NEC 645? Yes, but only under rare circumstances where it has been determined that the transport of data is critical to life safety or that there is extreme risk to facility operations.

Product Spotlight: Hospital Data Centers

As technology has evolved, so has the equipment located within a data center. Specifically, hospital data centers are always working to be one step ahead. Here are four new technologies that engineers may specify in a hospital data center.

UPS platform

The NXL UPS platform, manufactured by Liebert, is available in 250 to 750 kVA ratings, allowing it to support hospital data centers of various sizes. It features a color touch screen, enhanced cable access, and a compact design to reduce footprint. The 750 kVA model works with another Liebert product to extend and optimize the battery life, leading to reduced maintenance costs and superior data center safety. #1

VFD bypass

ABB’s E-Clipse Bypass for VFDs is the first bypass available with full serial communications capabilities and language display, allowing users to monitor information such as motor amps, volts, and kilowatts. It also features a regulated power supply, allowing it to operate during emergency generator tests, and is IBC 2005 Seismic certified. The product saves energy as well, calculating and displaying how much CO2 production was avoided by using the VFD. #2

Control switchgear

By providing engine control, load demand, and bus load optimization controls, the 7000 Series Generator Paralleling Control Switchgear by ASCO can be used for prime, emergency, and automatic standby power. The series is equipped with communications capabilities, such as power system monitoring and protection, as well as utility paralleling. #3


By offering flexible configurations, increased safety, easier specification, and simplified selective coordination as per NEC requirements, the Quik-Spec Coordination Panelboard by Cooper Bussmann is designed for use in a hospital data center. The panelboard can perform up to 600 Vac/200 A/200 kA short-circuit current rating, and is designed in the same footprint as conventional panelboards. #4

Author Information
Kuhlman has 20 years of experience in the design and construction of telecommunication infrastructure for microelectronics manufacturing facilities, data centers, laboratories, testing labs, office buildings, petrochemical plants, hospitals, and university campuses. He is a member of Consulting-Specifying Engineer’s editorial advisory board.

Data centers, defined

In order to apply the standards regarding data centers as outlined in NEC 645, a room must meet these five requirements:

• Emergency power off switch to disconnect power to IT room electronic and HVAC equipment

• Separate and dedicated HVAC system

• Listed IT equipment installed

• Room occupants limited to those operating or maintaining IT equipment

• Fire-rated wall to provide separation from other building occupancies.

A risk management decision

According to NFPA 75 Chapter 4, these are risk factors to consider in determining the need to apply NFPA 75.

IT rooms and data processing equipment:

• The impact to life safety function if the IT equipment room fails

• Fire threat of the installation to the occupants or property

• Economic losses from losing the function of the room, such as the loss of records or loss of equipment

• Increased regulatory impact due to failure to self-evaluate and implement measures to minimize losses to people and property, and effects on others

• Economic losses associated with loss of reputation

Communication rooms and data transport equipment:

• Evaluate the risk of a communications room causing damage and interruption to an IT room due to the loss of data and communications. If this is vital to operations, then NFPA 75 will apply to communication rooms and equipment.