NFPA Journal - Spring 2021 - 44

A new report by the Fire Protection
Research Foundation (FPRF) offers
answers. The 160-page " Obstructions
and Early Suppression Fast Response
Sprinklers, " published in August, summarizes six years of research conducted
by Wiss, Janney, Elstner Associates, Inc.,
the global engineering/architectural
firm that partnered with the FPRF on
this project. The research evaluated the
potential impact of obstructions on the
performance of ESFR sprinklers during
fires. The project also resulted in an
analytical tool that can simplify the decision-making process for the placement
of ESFR sprinklers in relation to various
obstruction configurations and sizes.
The findings could have important
ramifications for NFPA 13 and for
the stakeholders who rely on it. Data
collected from the ESFR obstruction
research is being reviewed by the NFPA
13 Technical Committee as part of its
discussions for possible changes to the

2022 edition of the standard. The committee has discussed modifying existing
requirements and adding new provisions in Chapter 14 to address isolated
and continuous obstructions below
ESFR sprinklers.

CREATING THE TESTS

ESFR sprinklers are the heavy hitters
of the sprinkler world in three important ways: they are designed to activate
quickly in order to achieve full suppression of a fire; they create large water
droplets that resist evaporation on
their way to the seat of a fire; and they
release an immense amount of water
to aid in suppression. Imagine driving
through a rain shower that your wipers
can handle easily: that's the output of a
typical sprinkler. Then imagine driving
in the kind of deluge where you can
hardly see beyond your windshield, one
so intense that you have to pull over
and wait for it to pass: that's an ESFR

sprinkler. Depending on the storage
scenario, ESFR sprinklers can eliminate
the need for in-rack sprinklers.
Despite that power, NFPA 13 contains a number of strict provisions for
installing ESFR sprinkler systems, in
part because of the hazardous nature
of the materials those systems are
designed to protect, and because the
systems can be designed to achieve full
extinguishment of a fire. An array of
building components, from structural
elements including beams and columns
to features such as ductwork, smoke
vents, lighting, and skylights, can all
impact the position and spacing of
ESFR sprinklers. According to NFPA
13, the options for installing ESFR
sprinklers near obstructions are limited
to adding another sprinkler below the
obstruction or removing the obstruction altogether-thus the joke that it's
easier to construct the building around
the sprinkler system. As the authors

In June, a fire destroyed a large Amazon distribution warehouse
in Redlands, California-a reminder of the potential hazard
posed by very large storage facilities packed with densely
stored commodities. AP/WIDE WORLD

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NFPA Journal - Spring 2021

Table of Contents for the Digital Edition of NFPA Journal - Spring 2021
