NFPA 13DR HDBK
Automatic Sprinkler Systems for Residential Occupancies Handbook
|Publication Date:||1 January 2016|
As indicated in its scope, NFPA 13D applies only to one- and two-family dwellings, such as those shown in Exhibit I.1.2, and manufactured homes. The term manufactured home refers to a portable vehicle as defined in 3.3.5, which used to be called a "mobile home." The size limits (i.e., height and area) of homes is not addressed by NFPA 13D. The philosophy is that two sprinklers will be able to control a fire in such a manner to prevent flashover in the room of origin for a long enough time to allow occupants to escape; therefore, the size of the home is not considered to be a concern or limiting factor. However, homes having ceiling constructions or room configurations that are beyond the basis of the two-sprinkler design criteria could require a greater number of sprinklers in the system design and/or a higher discharge flow rate to achieve the desired life safety objective.
NFPA 13D is written with life safety as the primary objective, with property protection a secondary concern. Still, field experience has demonstrated the ability of residential sprinkler systems to significantly limit property damage in many cases. If enhanced property protection is desired, additional protection beyond the requirements of NFPA 13D is likely to be necessary.
Because of a number of factors - including a two-sprinkler design discharge, the allowance for the omission of sprinklers in certain spaces, and a 10-minute water supply (7 minutes under specific conditions) - a sprinkler system installed in accordance with NFPA 13D is inappropriate for multifamily structures and occupancies. A multifamily occupancy contains three or more dwelling units. Sprinkler systems using residential sprinklers that are intended for multifamily facilities should be designed and installed in accordance with either NFPA 13R or NFPA 13.
The development of NFPA 13D did not consider the application of NFPA 13D for residential board and care facilities. However, the Technical Committee on Board and Care Facilities, which is part of NFPA's Life Safety Code project (NFPA 101®), has reviewed NFPA 13D and determined that it is appropriate for certain small board and care facilities where additional protection is provided. See NFPA 101 for more details.
Many requirements in NFPA 13D are based on full-scale fire tests conducted in dwellings and structures in Los Angeles, California, and Charlotte, North Carolina [Cote 1980; Cote 1982; Kung 1982; Moore 1980], and earlier laboratory tests conducted by Factory Mutual Research Corporation (now FM Global) and Battelle Columbus Laboratories (BCL) [Henderson 1978; Kung 1978]. Some of these tests indicated that the associated life safety objectives could be achieved with water application rates as low as 0.025 gpm/ft2 (1.02 mm/min). However, these tests usually involved smoldering fires in typical residential room configurations and flaming fires generated by a gas burner rather than by a fuel package consisting of household combustibles such as furniture and draperies. Subsequent tests at FM Global [Kung 1980] and at the test sites in Los Angeles and Charlotte [Cote 1980; Cote 1982; Kung 1982; Moore 1980] established that higher sprinkler water application rates were needed to address fires involving furniture near combustible vertical surfaces such as draperies.
Whether or not NFPA 13D is appropriate for multiple townhouse structures, similar to the one shown in Exhibit I.1.3, depends on how the townhouses are designed and constructed per the applicable building code. If the townhouses are constructed in accordance with a building code such as the International Residential Code (IRC), where each townhouse unit is considered a separate structure due to the use of appropriately fire-rated construction separating each of the units, then the use of NFPA 13D is appropriate and acceptable. In this case each individual townhome is a separate building in accordance with the code. The same would apply if every two townhomes are constructed as separate buildings per the building code. Where multiple townhouses (more than two) in the same structure are not separated by appropriately fire-rated construction, the application of NFPA 13D would not be correct. The definition of the term dwelling in 3.3.3 includes townhouses to clarify this issue
While the purpose of this standard is to provide improved protection against injury and loss of life, the use of these systems has demonstrated an ability to provide improved protection against property damage. Various levels of fire safety are available to dwelling occupants to provide life safety and property protection.
This standard recommends, but does not require, sprinklering of all areas in a dwelling; it permits sprinklers to be omitted in certain areas. These areas have been proved by NFPA statistics[see Table A.1.2(a), Table A.1.2(b), and Table A.1.2(c)]to be those where the incidence of life loss from fires in dwellings is low. Such an approach provides a reasonable degree of fire safety. Greater protection to both life and property is achieved by sprinklering all areas.
Guidance for the installation of smoke detectors and fire detection systems is found in NFPA 72.