Fire Protection In Mission Critical Facilities
- By Lance D. Harry, P.E.
- Aug 25, 2008
Note that evacuating the protected space is a general recommendation for any potential fire event.
The use of fire protection technology in “mission critical” facilities has long been a standard for most engineering, IT, and facilities professionals. Whether it be as simple as portable extinguishers or as complex as high sensitivity smoke detection coupled with clean agent suppression systems, some sort of fire protection is a must.
Historically speaking, mission critical facilities (MCFs) have garnered an elevated level of fire protection awareness because of two factors:
• MCFs involve a collection of highvalue assets, typically electronics, that have significant monetary value but are often even more valuable operationally. The cost of replacement and downtime associated with damage to these assets can be astronomical.
• MCFs inherently involve a greater level of risk than most commercial space because of the presence of both a constant ignition source (electricity) and a plentiful supply of fuel (generally, plastics, as in printed circuit boards (PCBs)).
The MCF itself can take on a number of different identities. The most common example in today’s business environment is the data center. Data centers are often the hub of a business’ operations, handling anything from internal communications (e-mail) to vendor/customer data, external order handling, and financial transaction processing. Data centers are found in all segments of the business landscape. Financial, telecommunications, and large manufacturing most commonly have numerous and extensive data center assets. Other examples of MCFs are network control centers, process control rooms, laboratory facilities, power generation facilities, testing environments, etc. The MCF is really defined by the company and owner. If the assets and operations are of particular value, it can certainly be deemed mission critical.
Fire protection in these facilities can be varied. Traditionally, systems have been sought that provide the greatest level of protection for the least cost. Level of protection can be loosely evaluated through two elements: extinguishing fire rapidly and effectively, and also minimizing associated damage to the protected assets. It is important to realize that, in most cases, MCF protection involves both structural protection (generally recommended throughout a given building) and asset protection (supplemental protection for the high-value asset).
In the ’60s, ’70s, and ’80s, halon compounds were prevalently used for the MCF application. Halon 1301 was the most common clean agent of the era. Some would argue halon 1301 was used more liberally than it should have been.However, its effectiveness in extinguishing fire and minimizing damage to the protected space was exemplary. Unfortunately, halon compounds contain either bromine or chlorine as one of their primary elements. Both elements are known ozone depletion contributors and were thus targeted by the Montreal Protocol, originally signed in 1987.The Montreal Protocol banned the production of ozone-depleting compounds, including halons, in most developed countries. Halon is still available today in recycled form, however. For example, in the United States, it is legal to recharge existing halon 1301 systems with recycled halon purchased from third-party suppliers and recycling groups. In the countries of the European Union, however, halon systems are no longer permitted and are required to be removed from service.
Fire Protection Evaluation
Fire protection system selection is a complex process that can involve a number of different entities, including internal company resources (financial, engineering, IT), outside consultants, insurance representatives, architects/ engineers, and the local authority having jurisdiction (AHJ). It is first important to understand the difference between code-required protection systems (most often, sprinkler systems) and supplemental asset protection.
Evaluating the need for supplemental protection should start with an analysis of the facility in question. Several different factors should be taken into consideration:
Analysis of the facility. The physical characteristics of the facility should be noted. In new construction, particular requirements often can be included, such as tightly sealed windows/doors and venting if necessary (see below for a discussion of various clean agents). In older facilities being outfitted with a suppression system, room integrity is of critical importance. If a room is overly “leaky” and will likely not achieve a level of integrity that is desired (or is too costly to do so), other strategies may need to be sought. Most local fire protection contractors can assist in a determination of room integrity for a given facility.
Hazard analysis.Understand the fire hazards within the space. It is most important to differentiate between class A (common combustibles such as plastics and fabrics) and class B (flammable liquids). Most MCFs contain only class A hazards, but a thorough review should be performed. This is also a good opportunity to investigate and evaluate the desire for “Emergency Power Off,” or EPO.Most fire protection professionals and codes recommend power be shut off to the electronic assets in the protected space prior to discharge of the system. In a facility where power is not shut off prior to discharge,some additional design considerations may need to be implemented. Consult your AHJ and system manufacturers for additional guidance in this area.
This article originally appeared in the August 2008 issue of Occupational Health & Safety.