Fire Protection Research Foundation report: "
Evaluation of Fire Flow Methodologies"
(PDF, 307 KB)
Author: Matthew E. Benfer and Joseph L. Scheffey, Hughes Associates, Inc. Baltimore, MD
Date of issue: January 2014
Introduction
The basic method for controlling building fires by fire departments is through the use of water, which is typically applied with manual hose lines or water monitors. This water can come from a municipal water supply, a private water supply, or from the fire department itself (i.e., water tenders). In order to effectively fight a fire, the water supply available must be adequate for the threat from the building and contents. The water requirements for firefighting include the rate of flow, the residual pressure required at that flow, the flow duration, and the total quantity of water required. As described in the NFPA Handbook [1], the American Water Works Association (AWWA) [2] defines the required fire flow as "the rate of water flow, at a residual pressure of 20 psi and for a specified duration that is necessary to control a major fire in a specific structure." Each fire flow methodology may define the objective of the required fire flow differently. There are a number of methods currently used to calculate required water flow rates for sprinklered and non-sprinklered properties. These methods are, in general, based on decades-old criteria derived using data from actual fires. Over the years, building construction methods, building contents, and fire suppression equipment and tactics have changed. The overall objective of this study is to assess the appropriateness of currently available fire flow methodologies. The first task in this project was a literature review of the existing fire flow calculation methodologies in the US and globally. The second task was a data analysis and GAP assessment to determine what additional information is needed to validate the existing fire flow calculation methodologies.