The formulas to calculate the required fire flow are:
ISU Method:
\[ RFF = \frac{V}{100} \]
NFA Method:
\[ RFF = \frac{L \times W}{3} \]
Where:
Fire flow is a measure of the total rate of water flow required to suppress a fire. Fire flow is most often expressed in gallons per minute. It’s often used as a rough estimate as opposed to an exact measure.
Let's assume the following values:
Using the NFA Method:
\[ RFF = \frac{30 \times 20}{3} = 200 \text{ GPM} \]
The Required Fire Flow (RFF) is 200 GPM.
Using the ISU Method:
\[ RFF = \frac{600}{100} = 6 \text{ GPM} \]
The Required Fire Flow (RFF) is 6 GPM.
