Dear Geir The New Zealand Fire Service has published a Code of Practice for Fighting Water Supply (NZS PAS 4509:2008) - which can be freely downloaded from our website
http://www.fire.org.nz/Business-Fire-Safety/Building-Design/Pages/Fire-safety-design.aspx Essentially there are two approaches you can take in this COP. A prescriptive approach using Tables. Table 1 matches Building type/size to a water classification, while Table 2 stipulates the required fire fighting water for this classification. Or you can use a fire engineering approach and match the (energy) quenching efficiency of water to the size of the fire that the fire fighters would be faced with upon arrival. I have simplified this a lot just to get across the main idea. Basically in answer to your question we want to encourage building owners to put the resource (water) where the risk is (which is within the building)! Thus the recognised advance of a sprinkler system which catches the fire whilst still small. So as a recognised trade-off, if a structure is sprinkler protected (and just using the prescriptive method of the COP), then it only requires an additional 25L/s fire fighting water. So the volume of (fire) water supplied to the building MUST be the amount required for the sprinkler and the (operational) fire fighting simultaneously. However as a caveat to this, if sprinklers are installed we do lend ourselves to negotiation on potentially allowing increased hydrant distances, slightly reduced volumes (dependent upon risk, proximity to a fire station, ease of fire fighting access around building, climatic conditions, exposure protection requirements, etc.) where the building is sited in a lower water serviced area than what is normally required OR if the amount of water that is required to supply BOTH the sprinkler system and fire fighting is greater than that required for just fire fighting (with no sprinkler system present). The latter is a very rare case and usually more an anomaly of the COP. Regards, James James Firestone Fire Engineer National Headquarters, NZ Fire Service P. O. Box 9346, Wellington, NZ Level 6, 5-7 Willeston St, Wellington, NZ Cell - 0274858056, DDI (04) 4708011 [email protected] Fires are fast - home sprinklers are faster - don't delay inquire about one today - see http://homesprinklers.fire.org.nz and keep yourself safe and NZ green. -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Geir Jensen Sent: Wednesday, 14 July 2010 01:59 To: [email protected] Subject: On which conditions does sprinkler substitute fire brigade water flow requirements? Never? Cannot figure out by NFPA 1 Ch 18 and NFPA 13. Sprinkler demand and hose demand are to be added, except for 50 % or 75 % reduction as per NFPA 1 Ch 18? How does NFPA 13 "hose allowance" relate to "fire flow requirements for buildings" (NFPA 1, 18.4)? Are they equal for a given sprinklered structure? Does sprinkler protection have any influence on water supply duration requirements? Shall duration comply with NFPA 1 or NFPA 13 for sprinklered structures? Are requirements to "hydrant water supply" and "fire flow requirements for buildings" both influenced, if any at all? Please accept the above very basic questions. I am working on guidelines for sprinkler trade offs. As guideline become performance-based I need to know if your prescriptive standards acknowledge sprinkler performance as is, i.e. say reducing water supply requirements (flow and duration) to a level sufficient for hose extinguishing of sprinkler controlled fires only. Geir Geir Jensen COWI Fire Technical Director _______________________________________________ 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) ---------------------------------------------------------------- This e-mail message has been scanned and cleared by MailMarshal ---------------------------------------------------------------- --------------------------------------------------------------- This e-mail message has been scanned and cleared by MailMarshal --------------------------------------------------------------- _______________________________________________ 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)
