Each new area in which we gain some useful knowledge becomes a stepping stone to another. If only half of the building were burning, 200. Response: Minimum required fire flow shall be submitted using correct format and calculation sheet before plan approval. This month’s Quick Drill involves flow requirements and the formulas that can help you determine fire flow needs, which will in turn help you in several other areas. The formula indicates that if the dwelling were fully involved, it would require 400 gpm to effectively control the fire. Having a good understanding of fire flow requirements is essential to everyone on the fireground–from the firefighter in the jump seat, who must know how much their handline is flowing and how many involved rooms it will put out, to the company officer making tactical decisions about where and when to attack the fire, to the chief officer defending their decision to dispatch four 1,500-gpm-rated engines to a building fire because it requires 6,000 gpm to control.Īsk a lot of firefighters how the whole extinguishment thing happens, and most will tell you the story about “putting wet stuff on the red stuff”–and in its own beautifully simple way, that’s true. I recently read an article that talked about, among other issues, the required fire flow for various fireground situations. The formula for calculating the needed foam concentrate at. FIRE-FLOW CALCULATION AREA (square feet) AUTOMATIC SPRINKLER SYSTEM (Design Standard) MINIMUM FIRE FLOW (gallons per minute) FLOW DURATION (hours) 03,600: No automatic sprinkler system: 1,000: 1: 3,601 and greater: No automatic sprinkler system: Value in Table B105.1(2) Duration in Table B105.

As a result, we must all have a basic understanding of the formulas that determine fire flow requirements.īTU, but there’s a lot more science to it than that. In order to understand the simple formula, it is important to know the components in a foam formula. There are several fire flow formulas in use today, but for the sake of space, we’ll only touch on two: the National Fire Academy (NFA) formula and the Iowa Rate of Flow. The NFA formula is based on offensive interior operations where less than 50 percent of the building is involved. The formula is:Įxample: For a 30′ x 50′ building that’s 25 percent involved, the flow would be 30 x 50 = 1,500 square feet, divided by 3 = 500 x 0.25 = 125 gpm.īased on that required fire flow, one handline pumped at the correct pressure should be able to produce the required gpm. The Iowa Rate of Flow is based on work performed by Keith Royer and Bill Nelson while they were working for Iowa State University’s fire training program. While studying the effects of fog streams on interior fires, the pair demonstrated that all you need to do is put the right amount of water in the right place for the fire to go out–something that’s often overlooked by the modern fire service. Using the fire flow formula, determine the required fire flow to the nearest.

Needed ifire flow equation