Letters

Dr. Gene Corley's guest commentary on sprinklers (January 2004 BD&C, p. 6) presents a bias that not all readers may be aware of. The title itself, "Reliance on Sprinklers a Mistake," is potentially misleading. The effectiveness of sprinklers in controlling fires in buildings is unmatched, and it is not a mistake to rely on them.

The example of the World Trade Center is too extreme to conclude that sprinkler systems are commonly overwhelmed. In that example, the design envelopes for both the building and the sprinklers were greatly exceeded.

Dr. Corley cites NFPA statistics that sprinklers do not operate 16% of the time. This, too, is potentially misleading. The NFPA publication that discusses sprinkler use and reliability is "U.S. Experience With Sprinklers," by Kimberly D. Rohr, Fire Analysis and Research Division of NFPA, November 2003. Page 11 of this publication states: "… the percentages (of cited reliability of sprinklers) may be misleadingly low because the data do not separate cases where sprinklers could not be expected to operate."

Cases where sprinklers could not be expected to operate (or to operate but not control fire) include:

• Partially sprinklered buildings where the fire starts in an unsprinklered area;
• Buildings in which sprinklers have been turned off;
• Areas where sprinklers have been blocked or obstructed;
• Storage areas with unanticipated storage placed in aisles;
• Buildings where the occupancy hazard has increased.

Relying on sprinklers for fire protection brings with it the responsibility to keep them operational. This responsibility includes addressing all the above points.

Like relying on sprinklers, relying on building construction features for damage control brings the responsibility for keeping them operational, including the following: sealing duct, pipe and conduit penetrations through fire barriers; installing fire dampers inside ducts that penetrate fire barriers; confirming that fire dampers operate automatically and close fully; installing fire doors in fire wall openings; keeping fire doors in good repair; confirming that fire doors are not blocked open; and confirming that fire doors operate automatically and close fully.

The risk of failure of sprinklers and building construction features can vary, and this risk can be controlled. Risk management techniques can help find the best combination of sprinkler design and construction features for any building. One need not be downplayed at the expense of the other.

Jane I. Lataille, P.E., Fire Protection Engineer, Los Alamos National Laboratory