Improvement in fire suppression systems has been the focus of not only the construction industry but also by fire risk management agencies (Liu and Kim, 1999, p.32). This is the reason why experimental and computational modeling studies were used by Liu and Kim (1999, p.32) to not only validate fire tests but to improve the effectiveness and efficiency of fire suppression systems. Computing for water spray characteristics includes ventilation conditions of the area, droplet size, and flux density (Liu and Kim, 1999, p.32). The purpose of which is to improve fire suppression strategies especially in different fire scenarios (Liu and Kim, 1999, p.32).
In order to develop fire suppression strategies, the flow rate of the water supply must be considered adequate in handling potential fire incidents (Wilson, 2012, p.24) especially for different fire scenarios (Liu and Kim, 1999, p.32). Wilson (2012, p.24) revealed that an adequate flow rate is primarily based on the reliability and capacity of the water supplied by the municipal water delivery system. This means that an incident commander must understand how the municipal water delivery system works from the adequacy of its water source to the reliability of the water flow (Hickey, 2008, p.5). The reason for this consideration is that the incident commander needs to determine if the municipal water delivery system is adequate and reliable (Hickey, 2008, p.1) for fire suppression requirements aside from the domestic and commercial demands.
Hickey (2008, p.5) revealed that the water supply must have an estimated fire flow of 500 gallons per minute (gpm) at a minimum of 2 hours. But the amount of water needed is primarily dependent on the size of the buildings and number of occupants, which is usually suggested by the Insurance Services Office or ISO (Hickey, 2008, p.9). The reason for the ISO suggestion is that water supply flow differs based on the structure location, which are classified into commercial, residential, institutional, industrial, and mercantile (Hickey, 2008, p.9). The ISO only requires a minimum of a 250 gpm water flow but the residential properties usually have a water flow of 500 gpm while commercial properties use 12,000 gpm (Hickey, 2008, p.9).
The fire incident commander must also be aware of the location and spacing of the fire hydrants, the purpose of which is to make it convenient for fire department use (Hickey, 2008, p.47). The reason for the fire hydrant spacing design is to take advantage of the water flow (Hickey, 2008, p.47) in order to minimize the spread of fire from one structure to another. The water flow computed from each fire hydrant must conform to a minimum of 250 gpm with a 20 psi residual pressure as suggested by the ISO (Hickey, 2008, p.48). Therefore the fire incident commander must consider not only the design of the municipal water delivery system but also the minimum flow rate and the location of the fire hydrants when designing their incident action plan for the entire municipality.
References
Hickey, H. E. (2008). Water supply systems and evaluation methods: Volume 1. U.S. Fire Administration. Retrieved from https://www.usfa.fema.gov/downloads/pdf/publications/Water_Supply_Systems_Volume_I.pdf
Liu, Z., and Kim, A. K. (1999). A review of water mist fire suppression systems – fundamental studies. Journal of Fire Protection Engineering, 10(3), 32-50.
Wilson, D. K. (2012). Fire alarm notebook: Fire pump supervision – part 1. IMSA Journal. Retrieved from http://www.imsasafety.org/journal/so10/4.pdf
