Data center design: Fire and life safety

In the information age, data centers are one of the most critical components of a facility. If the data center isn’t reliable, business can’t be done. Fire and life safety issues are tackled here.


Kevin V. Dickens, PE, LEED BD+C, Mission critical design principal, Jacobs Engineering, St. Louis. Courtesy: Jacobs Engineering Terrence J. Gillick, President, Primary Integration Solutions Inc., Charlotte, N.C. Courtesy: Primary Integration SolutionsBill Kosik, PE, CEM, BEMP, LEED AP BD+C , Principal data center energy technologist, HP Technology Services, Chicago. Courtesy: HP Technology ServicesKeith Lane, PE, RCDD, NTS, RTPM, LC, LEED AP BD+C, President/CEO, Lane Coburn & Associates LLC, Bothell, Wash. Courtesy: Lane Coburn & AssociatesDavid E. Wesemann, PE, LEED AP, ATD, President, Spectrum Engineers Inc., Salt Lake City. Courtesy: Spectrum Engineers Inc.


CSE: What trends and events have affected changes in fire detection/suppression systems in data centers?

Wesemann: The highly sensitive air sampling systems are very common for data centers due to their early detection of potential fires. This coupled with a gaseous clean-agent type suppression system helps to avoid the risk of introducing water from wet sprinklers into the data center (although many codes and jurisdictions still require traditional sprinkler systems even if clean agent suppression systems are present).

Gillick: To varying degrees, philosophical, code, and insurance trends all have affected changes in life safety/fire suppression systems in data centers. From a fire detection standpoint, we are seeing the deployment of early detection warning systems, such as very early smoke detection apparatus (VESDA), which detect the elements of combustion at the atomic level and indicate a pending fire. Another area in which we’ve seen significant change is within the data center enclosure, where we are being asked to commission various combinations of water, dry-pipe reaction, and gaseous suppression systems depending on the facility. Additionally, many of the medium- and high-density rack enclosures require fire suppression systems within the enclosure, which vary by local jurisdictions and code requirements.

CSE: How have the costs and complexity of fire protection systems changed in recent years?

Gillick: The cost and complexity of dry-pipe and gaseous systems have increased in recent years. As a result, some owners are selecting wet-pipe systems with the approval of their insurance carriers. 

CSE: What changes in clean agent suppression systems have you seen in data centers recently? What do you see changing in the near future?

Wesemann: FM200 seems to be a popular suppression system still. I’ve seen some nitrogen misting systems being used.

Gillick: Due to the cost of clean agent suppression systems and the storage requirements of the gas canisters, owners are considering the volume of space in which they want to deploy these systems: full flood of the white space area between the ceiling grid and the raised floor, within the raised floor plenum or ceiling plenum, or all of the above? We are starting to see the emergence on the market of new gases, fostering the retrofit or replacement of some of the legacy systems. Overall, I do not see owners deploying clean agent systems as extensively now as they did in the past, and that trend may continue in the near future. 

CSE: What are some important factors to consider when designing a fire and life safety system in a mixed-use building (data center within an office building, for example)? What things often get overlooked?

Wesemann: In mixed-use buildings, data centers have to be designed as stand-alone facilities with their unique requirements for fire detection and suppression, but then report to the main building fire alarm system. Likewise, the building system needs to report to the data center. Sometimes the “overlay” of the two systems (which can be the same system with two functions) gets confusing, especially if the same signal tone is used to annunciate both types of alarms (those generated within the data center and those generated in other areas of the mixed-use building).

Gillick: There are two very important factors to consider in the context of fire and life safety in a mixed-use building: first, design of a dedicated MEP system for the data center, which will enable it to continue operation as a stand-alone structure in the event of a fire or other catastrophic event; and second, development of contingency plans to protect the space if code requires that a fire alarm condition must unlock all doors. You’d be surprised how often these factors are overlooked until someone has observed the consequences of a fire department shutdown of MEP services to the entire building, or intruders entering unlocked and unprotected doors. 

CSE: In a mission critical facility such as a hospital, what unique emergency notification or mass notification systems have you specified, and what challenges did you overcome?

Gillick: More than in any other type of mission critical facility, a hospital requires integration of many layers of internal communication systems—emergency mass notification systems, fire alarm notification, security, paging, nurse-call, handheld online records, etc.—with the building telecommunication and security systems. The challenges include correct zoning of the announcements and coordination with architectural design for signage, assembly places, shelter-in-place areas, and so forth. 

Wesemann: Voice annunciation systems with the ability to broadcast prerecorded and live messages are often used. The biggest challenge with the voice systems is the NFPA intelligibility requirements that are difficult to predict using traditional design methods and rules of thumb. We often have to involve our acoustical engineer with computerized design and modeling tools to ensure intelligibility.

Robert , AZ, United States, 01/28/14 03:08 PM:

I appreciate the responses to these questions as they show that fire detection, suppression, and life safety systems have to be designed as integrated systems, and not isolated silos. Regarding the cost of clean agent suppression systems there is some evidence to suggest that prices will continue to decline in the future due to increased competition, expiration of patents, and retrofit options that can utilize the existing mechanical piping. The advent of more systems using all “natural gases” also offers the prospect of financial relief in the event of a discharge, which has to be considered when specifying a system. All in all, we've seen a sizable decrease in equipment cost from the systems first used to replace Halon 1301, and there could be more to come. Thanks again for your thoughtful dialogue.
Mohsin , OR, United States, 02/06/14 03:05 PM:

It is unfortunate to note that the use of automatic gaseous fire extinguishing systems is still not Code mandated here in the US market place.
This is not the case in Europe and the Middle East, in particular.
It is disheartening to note and see sprinkler systems used that extensively in data centers and other key sensitive areas. Apparently, the sprinkler lobby here in the US has done a good job and it’s time for the rude awakening. A case from the recent NFPA journal may serve as a daring example in this regard. Somewhere in the East Coast, a modern warehouse facility caught fire and despite all the intervening efforts of a number of fire departments from the adjoining Cities and Counties, this modern and recently built facility was a colossal loss.
The insurance company assigned the task to "Hughes Associates" to investigate and suggest provision of early detection systems for future scenarios.....The warehouse had no detection system and just the sprinkler the full story in NFPA journal to be enlightened further on this subject.....Sprinklers are good, even great but please do not be sold out that everything is fine and dandy with just a sprinkler system in place. After all, that day has not dawned as yet where a typical sprinkler head can act in part at least to respond to the presence of dense smoke as well. It’s a topic of ........
Lastly, I would like to mention that the use of Water Mist Systems as a substitute for the ozone depleting halons is slowly but surely gaining momentum but again water mist miniscule droplets are not the same as water from sprinkler heads.
Irony of the matter is that even preaction systems which require some form of early detection for system actuation are seeing a push-back in some areas and States. This subject was brought up to our attention during the most recent meeting of the Cascade Chapter of SFPE here in the Portland, Oregon area.
Simply put, this is unacceptable.
Reason: A sprinkler head no matter how fancy a term you can use to describe it (Fast response/Early Discharge) or whatever, are not and will never be a substitute for early warning and very early warning detection systems.
VESDA = (Very Early Smoke Detection Apparatus) system, way to go (thumbs up).
Concluding Remarks:
Fire is the greatest of servants but what a master and master it truly becomes when fire has taken a foot hold. Remember the 3 minute rule.....Early detection and intervention is the key, why wait for the flames to appear. Even for property protection and mission critical facilities and operations, this is of paramount importance.
I sincerely hope that I have not offended any one here. For once, you are to blame for providing all the prompts in your article.
Sharing is power, though.
Keep it up!
M. Malik
PAUL , AR, United States, 02/12/14 05:48 PM:

In research that I did a few years ago, I discovered that this is where “Electronic Computer/Data Processing Equipment” is specifically addressed by the National Electrical Code NFPA 70.
The code deferred to protection provisions of NFPA 75, Standard for the Protection of Information Technology Equipment

In NFPA 75 1999 Ed, it stated the following: ( Note this is consistent with the 2013 Edition of NFPA 75.)
The computer area shall be separated from other occupancies within the building, including atria or other open-space construction, by fire-resistant-rated construction. The computer room shall be separated from other occupancies in the computer area by fire-resistant-rated construction. The fire resistance rating shall be commensurate with the exposure but not less than 1 hour for both.

NFPA 75, 2013 The fire resistance rating shall be commensurate with
the exposure but not less than 1 hour for both.

Excerpts from NFPA 70 Article 645, 2011
Information Technology Equipment (ITE). Equipment and
systems rated 600 volts or less, normally found in offices or
other business establishments and similar environments
classified as ordinary locations, that are used for creation
and manipulation of data, voice, video, and similar signals
that are not communications equipment as defined in Part I
of Article 100 and do not process communications circuits
as defined in 800.2.

Informational Note: For information on listing requirements
for both information technology equipment and communications
equipment, see UL 60950-1-2007, Information Technology
Equipment - Safety - Part 1: General Requirements.

Information Technology Equipment Room. A room within
the information technology equipment area that contains the
information technology equipment. [75:3.3.9]

645.4 Special Requirements for Information Technology
Equipment Room. This article shall be permitted to
provide alternate wiring methods to the provisions of Chapter
3 and Article 708 for power wiring, Parts I and III of
Article 725 for signaling wiring, and Parts I and V of Article
725 for optical fiber cabling where all of the following conditions are met:

(1) Disconnecting means complying with 645.10 are provided.

(2) A heating/ventilating/air-conditioning (HVAC) system
is provided in one of the methods identified in 645.4(2) a or b.

a. A separate HVAC system that is dedicated for information
technology equipment use and is separated
from other areas of occupancy; or

b. An HVAC system that serves other occupancies and
meets all of the following:
i. Also serves the information technology equipment room
ii. Provides fire/smoke dampers at the point of penetration
of the room boundary
iii. Activates the damper operation upon initiation
by smoke detector alarms, by operation of the
disconnecting means required by 645.10, or by both

Informational Note: For further information, see NFPA 75-
2013, Standard for the Protection of Information Technology
Equipment, Chapter 10, 10.1, 10.1.1, 10.1.2, and 10.1.3.

(3) All information technology and communications equipment
installed in the room is listed.

(4) The room is occupied by, and accessible to, only those
personnel needed for the maintenance and functional operation
of the installed information technology equipment.

(5) The room is separated from other occupancies by fire-resistant-
rated walls, floors, and ceilings with protected openings.

Informational Note: For further information on room construction
requirements, see NFPA 75-2013, Standard for the
Protection of Information Technology Equipment, Chapter 5.

(6) Only electrical equipment and wiring associated with
the operation of the information technology room is
installed in the room.

Informational Note: HVAC systems, communications systems,
and monitoring systems such as telephone, fire alarm
systems, security systems, water detection systems, and
other related protective equipment are examples of equipment
associated with the operation of the information technology room.
James , Australia, 02/21/14 08:34 AM:

I find it interesting that no mention has been made of Hypoxic fire prevention, by controlling the oxygen level within the risk to be protected, fire is actively controlled.
Hypoxic fire prevention is by far (in my opinion) the best way to protect against the risk of fire without need of expensive pressure tests and the chance of accidental discharge.
Further more the implementation of these systems do no adverse affects to sensitive equipment by acoustic shock from discharge or damage by water etc.
I am more than happy to discuss the ins and outs of these systems as I believe they are often misunderstood or unknown.

James Phelps
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