If you're talking about the fire flows referenced in the IFC, Appendix B, this seems to be an AHJ or IU call. For the most part when the building is fully sprinklered only the sprinkler system demand and hose stream demands are used for water tank sizing. I've not had one AHJ or IU apply the fire flow section of the IFC to the water supply when those conditions exist. Now when a building is not protected I have had this section of the IFC applied. However note that this section is not mandatory and is not a part of the actual Code. See wording at the top of the first page. So it requires clarification from the AHJ and/or IU as to what is applicable. But if there is no direction we use it as the basis.
Also note that the 75% reduction is "up to 75%" and "as approved", so it's not an automatic reduction. Craig L. Prahl, CET Fire Protection Specialist Mechanical Department CH2MHILL Lockwood Greene 1500 International Drive PO Box 491, Spartanburg, SC 29304-0491 Direct - 864.599.4102 Fax - 864.599.8439 [email protected] http://www.ch2m.com -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Ron Greenman Sent: Thursday, September 03, 2009 3:40 PM To: [email protected] Subject: Fire Flow When determining tank size on a property supplied only from a tank is the sprinkler demand added to fire flow as a cumulative fire flow or is it considered part of the fire flow? And if the former does the hose stream need to be added or is it negated by the fact that the tank is already supplying the hydrants? Example: 30,000 sqft fully sprinklered building requires a fire flow (reduced 75% then rounded up to the minimum) of 1500 gpm for 2 hours requiring a 180,000 gallon tank. The sprinkler demand is 650 gpm plus a 250 gpm hose stream for one hour for a total of 54,000 gallons. Is the 54K gallons included in whole or in part with the fire flow storage or is it added? Thanks. -- Ron Greenman Instructor Fire Protection Engineering Bates Technical College Tacoma, WA Member: SFPE, ASCET, NFPA, AFSA, NFSA AFAA _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
