An IAFC Member Alert dated May 10, 2002, suggested that IAFC members vote in a particular way on six issues that may be discussed on the floor at the upcoming NFPA meeting in Minneapolis with regard to the proposed 2002 edition of NFPA 13D – Sprinkler Systems for One and Two-Family Dwellings and Manufactured Homes. The memo twice mentioned the National Fire Sprinkler Association, and attempted to ascribe motives to some of the NFSA positions. The purpose of this response is to provide IAFC members and others with some additional information on which to base their own decisions on these issues. The NFSA has a long history of working in cooperation with the IAFC on improved fire protection in general, and residential sprinkler protection in particular.
This
was listed as number 5 in the IAFC memo, but was labeled as the “highest
priority” issue. We would agree that it
is the highest priority, since it represents the most fundamental issue with
regard to residential sprinklers, namely whether they will effectively control
a residential fire. In January of 1999, Factory Mutual called an emergency
meeting for the sprinkler industry, and revealed the results of fire tests they
had conducted on listed residential sprinklers: many of the recently-listed
low-flow sprinklers could not control the same fire test that they had
presumably handled at the time of their listing. This led to a cooperative study by FM, Underwriters Laboratories
and the sprinkler manufacturers that found the existing residential fire test,
intended to represent a fairly severe corner furniture arrangement, contained a
great deal of variability. An 18-month
“recalibration” program took place, involving the development of a new,
consistent fire test.
Concurrent
with that effort, we asked the NFPA Committee on Residential Sprinklers for
guidance, and explained that preliminary testing indicated that true
equivalency with the corner furniture scenario used as the basis of the
residential sprinkler in the late 1970s would lead to a minimum 0.05 gpm/sq ft
density. The Committee made the
decision to maintain the severity of the original fire challenge, which in turn
has led the laboratories and the sprinkler manufacturers to endorse the
absolute minimum of 0.05 gpm/sq ft. It
should be noted that this density represents a substantial reduction from the 1980
edition of NFPA 13D that introduced residential sprinklers. The minimum flows of 18 gpm for the first
sprinkler and 13 gpm for each of two, in combination with the maximum coverage
areas of 144 sq. ft., resulted in densities of 0.125 gpm/sq ft and 0.09 gpm/sq
ft respectively. In fact, without the
addition of the proposed 0.05 gpm/sq ft. minimum, 13D could be interpreted to
still require these higher minimums.
The new minimum represents only about half the minimum allowed for the
first generation residential sprinklers, established with the benefit of
millions of dollars of federal fire research.
Should we allow even lower? All
test data says no, including fire tests of American sprinklers conducted last
year by the Swedish test lab SP and only recently published. The Swedish tests, involving fires
originating in upholstered furniture, showed that densities of 0.05 gpm/sq. ft.
showed “reasonably good protection”. As
might be expected, better results were obtained with densities of 0.1 gpm/sq
ft., the traditional level for light hazard protection.
The
fire sprinkler industry is proud of the gains we have made and the economies
introduced with lower flow residential sprinklers. But we believe it would be irresponsible to allow lesser water
discharge rates than those being proposed by the Committee. While experience
has shown that many of the fires in dwellings take place in kitchens or other
areas in which fires which can be controlled with lesser densities, the NFPA
13D Committee decided to maintain the “reasonably worst case” upholstered furniture
corner fire as the benchmark fire, and we support that decision.
The
flow alarm is not intended as an evacuation alarm and we agree that it will
therefore not necessarily contribute to life safety in any single fire. However, experience has shown that it is
necessary in order to maintain confidence in 13D systems, which will save lives
in the long run. Communities with
residential sprinkler mandates, such as Scottsdale, Arizona and Greenburgh, NY,
have found the flow alarm is needed to minimize the potential for water damage
in the event of an inadvertent operation of a sprinkler or following successful
fire control by sprinklers.
There
is no philosophical or technical issue here, only the recognition that
everything that could be done by means of this chapter can be done in other
ways. For example, the special allowance for a 7-minute water supply also
appears in Chapter 2. In fact, these “limited
area systems” require a minimum flow of 10 gpm for the first sprinkler and 6.5
gpm for each of two, with maximum areas of coverage of 64 sq. ft, meaning that
they require minimum densities of 0.16 gpm/sq. ft and 0.10 gpm/sq. ft, more
than twice the proposed new minimums discussed above.
Because
plumbing codes limit maximum pressures on domestic water systems, pressure
reducing valves will be commonly installed on combined sprinkler/domestic
systems. Recognizing that failure of these
valves will compromise the sprinkler protection, the Committee is merely
seeking to ensure a minimum level of quality and reliability.
* * * * *
It
should be noted that the NFPA Committee on Residential Sprinkler Systems has
effectively established consensus on the above issues. All of these items have gone through public
comment and have maintained the support of the Committee as evidenced by
successful balloting. We believe they
are sound and do not plan to discuss them on the floor unless they are
challenged by some other party.
Included
in the IAFC memo are two additional issues that the NFSA plans to bring up for
floor discussion. Both of these
proposals received the support of the majority of Committee members, but failed
to achieve the two-thirds support needed for a successful ballot:
5
gpm Add-on for Combined Systems
Nonmetallic piping for non-combined systems must be listed for fire sprinkler use. The listing in turn specifies the minimum protection for the piping to ensure that water will reach the sprinklers. Only for a combined sprinkler/domestic system is non-listed piping allowed to be connected to the sprinklers. The 5 gpm add-on is intended to account for simultaneous losses that might take place during a fire event.
In
his negative ballot, IAFC representative Baker noted that the 5 gpm appears
arbitrary, and that more study is needed.
The Committee chose this figure because 5 gpm is already used within
NFPA 13D as the appropriate simultaneous domestic demand for a two-family
dwelling. Perhaps additional study will
lead to a future refinement, but the intent here is to ensure water for the
sprinklers as these systems are installed today.
Water
softeners and other water treatment equipment are very commonly added to
domestic systems by the homeowner. If
this takes place improperly with a combined sprinkler/domestic system, it could
compromise the sprinkler protection.
The bypass is a way of ensuring proper sprinkler protection.
IAFC
representative Baker voted against this issue on the basis of three points:
that the Committee does require a redesign of the system if a water softener is
added, that there is no evidence of past problems, and that this would add to
the cost of the combined system.
We
would not expect evidence of past problems inasmuch as the promotion of the
combined systems is a new phenomenon.
While we agree there would be a cost impact, we believe it is justified
since we have no confidence that the homeowner will undertake the effort to
redesign the sprinkler system when the water softener is added.
* * * * *
We
encourage all IAFC and other NFPA members to review the Report on Proposals and
Report on Comments and make up their own minds with regard to the six issues
presented above. In all cases, the NFSA
position is the position supported by the majority of Committee members.
The
IAFC Member Alert appears to oppose anything that would add cost to any NFPA
13D system. While we respect the goal
of low cost for 13D systems, it should not be achieved by low performance. All standards result in higher costs. We justify the cost of standards through
recognition that the net benefit exceeds the cost. So the discussion on these six issues should relate to the net
benefits of protection.
There
appears to be special sensitivity to the issues related to combined
sprinkler/domestic systems. These
systems can be expected to demonstrate high performance, but only if the
appropriate safeguards are in place. The
proponents of one particular type of combined sprinkler/domestic system are
viewing the above issues as if they related solely to their particular system,
and that is simply not true. True
proponents of residential sprinkler protection need to look at the bigger
picture, and not attempt to write the standard around a proprietary product.
It
is the effectiveness of residential sprinklers that continues to be the number
one factor in the continued growth of residential sprinkler protection. We ask for your help in maintaining that
effectiveness.