• U.S. Experience with Sprinklers
• Smoke Alarms in U.S. Home Fires
• Non-Water Based Automatic Fire Extinguishing Equipment

U.S. Experience with Sprinklers

Includes statistics on how often sprinklers are reported in fires, by property use, and their estimated impact in reducing the average loss of life and property per fire. Includes statistics on performance, usage and reliability of sprinklers, as well as leading reasons when system fail to operate or operate but are ineffective. Also includes special study statistics on non-fire sprinkler activations.

Executive Summary
Automatic sprinklers are highly effective and reliable elements of total system designs for fire protection in buildings. According to the 2009 American Housing Survey, in 2009, 4.6% of occupied homes (including multi-unit) had sprinklers, up from 3.9% in 2007, and 18.5% of occupied home built in the previous four years had sprinklers.                                                       

Of reported 2006-2010 structure fires, an estimated 9% showed sprinklers present.* Sprinklers were reported as present in 55% of reported fires in health care properties.  Manufacturing facilities (48%), hotels and motels (51%), prisons and jails (53%), and dormitories and barracks (53%), all had sprinklers reported in at least half of reported structure fires. In most other property uses, at least two-thirds of all reported fires were reported as sprinklers not present. 

Sprinklers are still rare in most of the places where people are most exposed to fire, including educational properties (34% of fires), stores and offices (23%), public assembly properties (23%), and especially homes (6%), where most fire deaths occur. There is considerable potential for expanded use of sprinklers to reduce the loss of life and property to fire. 

Sprinkler systems are carefully designed to activate early in a real fire but not to activate in a non-fire situation. Each sprinkler reacts only to the fire conditions in its area. Water release in a fire is generally much less than would occur if the fire department had to suppress the fire, because later action means more fire, which means more water is needed. Water release with no fire is rare compared to water release in response to a fire. 

Sprinklers operated in 91% of all reported structure fires large enough to activate sprinklers, excluding buildings under construction and buildings without sprinklers in the fire area. When sprinklers operated, they were effective 96% of the time, resulting in a combined performance of operating effectively in 88% of all reported fires where sprinklers were present in the fire area and fire was large enough to activate them. The more widely used wet pipe sprinklers operated effectively 89% of the time, while dry pipe sprinklers operated effectively in 76% of cases. 

As defined in NFPA 13, section 3.4, a wet pipe sprinkler system has sprinklers attached to a piping system containing water so that water discharges immediately from sprinklers opened by heat from a fire, while a dry pipe sprinkler system has sprinklers attached to a piping system containing air or nitrogen under pressure so that sprinkler activation releases the air or nitrogen, allowing water pressure to open a valve and water to flow into the piping system and out the opened sprinklers.

With wet-pipe sprinklers the fire death rate per 1,000 reported home structure fires was lower by 83% and the rate of property damage per reported home structure fire was lower by 69%. For more on NFPA’s Home Fire Sprinkler Initiative, go to http:/www.firesprinklerinitiative.org.

*These estimates are projections based on the detailed information collected in Version 5.0 of the U.S. Fire Administration's National Fire Incident Reporting System (NFIRS 5.0) and the NFPA's annual fire department experience survey. These statistics exclude buildings under construction and cases of failure or ineffectiveness because of a lack of sprinklers in the fire area and after some recoding between failure and ineffectiveness based on reasons given.  Because fires reported as confined fires are reported without sprinkler performance details or as fires too small to activate operating equipment, confined fires are not included in any analysis involving reliability or effectiveness of automatic extinguishing equipment.  See Appendixes A and B for additional details of statistical methodology, including the distinction between confined and non-confined fires.

When sprinklers fail to operate, the reason most often given (63% of failures) was shutoff of the system before fire began, as may occur in the course of routine inspection or maintenance.  Other leading reasons included manual intervention that defeated the system (18%), lack of maintenance (6%), and inappropriate system for the type of fire (5%).  Only 8% of sprinkler failures were attributed to component damage.

When sprinklers operate but are ineffective, the reason usually had to do with an insufficiency of water applied to the fire, either because water did not reach the fire (53% of cases of ineffective performance) or because not enough water was released (18% of cases of ineffective performances).  Other leading reasons were manual intervention that defeated the system (9%), system component damage (9%), lack of maintenance (8%), and inappropriate system for the type of fire (3%).