Coffee Break Training: Access and Water Supplies: Fire Flow Formulas: Part 9: Insurance Services Office Needed Fire Flow Formula: Effective Area Calculation [open pdf - 538KB]
"Learning Objective: The student will be able to compute an example of the Insurance Services Office (ISO) 'construction factor' subformula that is included in the Needed Fire Flow (NFF) formula." This Coffee Break Training includes the formula for ISO NFF, with detailed instructions on how to complete the formula.
Coffee Break Training - Fire Protection Series No. FP-2013-44
United States Fire Administration: http://www.usfa.fema.gov/