Smoke exhaust will use smoke as the fire signature (not heat) as the means to start the fans. The intent is to catch the fire early and prevent untenable situations. The quickest detectable fire signature for this scenario will be smoke, not heat (although there is more to the story, but just keeping it simple for this discussion). Typically there are duct detectors to detect the smoke. There are also local application smoke detectors near openings in the smoke barriers that will automatically close the doors to prevent smoke migration from one compartment to the other. There may also be smoke detection throughout the smoke compartment. The whole purpose is to keep adjacent areas tenable to allow zoned evacuation. If the adjacent areas becomes untenable, then an evacuation message will annunciate in that zone as well. Not to mention if it becomes untenable the entire fire safety plan has failed.
***Please note our new address*** Duane Johnson, PE Design Manager Strickland Fire Protection 4011 Penn Belt Place Forestville, MD 20747 301-474-1136 Office 301-455-0010 Cell -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of Brad Casterline Sent: Monday, April 18, 2016 2:58 PM To: [email protected] Subject: RE: [EXTERNAL] Re: Fire Sprinkler Plan to Match Evacuation Plan?? Peter, Is it true that the 'smoke protected' systems you refer to require smoke detectors? If you are waiting 2 or 3 minutes for a sprinkler to operate, and add a 60 second flow switch retard feature, plus if there are exhast fans a 10 second ramp-up to full strength, these defend in place safe areas adjacent to the origin are already likely untenable. And you mentioned non-sprinklered facilities, so wouldn't the same Smoke, Evac, and FA matching footprint rules apply whether there were flow switches or not? Just curious, Brad On Apr 18, 2016 1:35 PM, "Larrimer, Peter A" <[email protected]> wrote: > There must be one water flow alarm switch per smoke zone. When we > "defend in place" or defend in a safe place, that safe place is > usually a smoke zone that is separate from the zone of fire origin. > If there is only one sprinkler switch on a floor and there happens to > be three smoke zones, the one sprinkler switch cannot be programmed to > identify anything other than the floor. In that scenario, an alarm > would not be able to be programmed to tell staff where the fire is > located. Staff would only be able to be directed to the floor and not > the smoke zone of fire origin. Ideally, the sprinklers would be fed > from three risers through three separate flow switches so that the > signal sent over the fire alarm system would identify the zone of fire > origin to the staff. Each sprinkler tends to serves as an initiating > device to the fire alarm system through its respective flow switch. > > The VA intends to provide one sprinkler zone per each smoke zone for > the reasons stated above. The codes are not specific on the details. > Some could argue that multiple smoke zones within a single sprinkler > zone could be provided and it would be compliant with the codes that I > have referenced. I don't disagree. However, how does the facility > try to write a fire plan and explain to staff that the fire alarm > system will tell you where to go when there is an alarm unless the > alarm is activated by the sprinkler system alarm in which case the > system can only tell you the floor where the fire is and not the zone. > It just makes it difficult for our personnel to respond quickly to a fire. > > Note: A sprinkler system could be installed in a two story healthcare > building (defend in place) that has 3 or more smoke zones per floor > and have only one water flow switch for the whole building and the > installation would be in compliance with NFPA 13. Unfortunately, if > the fire alarm system was initiated by the sprinkler system water flow > switch, the fire alarm system would not be able to identify the fire > origin since the one and only switch would be activated for any sprinkler in > the building. > Where would the staff go to help assist with patient relocation? > > Hope this helps. > > Peter Larrimer > VA > > > > > -----Original Message----- > From: Sprinklerforum [mailto: > [email protected]] On Behalf Of > [email protected] > Sent: Monday, April 18, 2016 12:05 PM > To: [email protected] > Subject: RE: [EXTERNAL] Re: Fire Sprinkler Plan to Match Evacuation Plan?? > > Hi Peter, > > I have two related questions on your response, for clarification. > > First question: When you say "However, the fire alarm system can only > send the proper alarm signal from a sprinkler system if the sprinkler > system has a water flow switch per zone." Do you intend that to mean, > "if the sprinkler system has a water flow switch per "smoke zone", or > per "sprinkler zone"? > > Second question: When you say "Therefore, VA requires the sprinkler > zones to be coincidental with the smoke zones...". Do you intend that > to mean "one sprinkler zone=one smoke zone" or "one sprinkler zone= > one or more smoke zones", and that the boundary of the sprinkler zone > coincides with the boundary of all encompassed smoke zones. > > Based upon your reference to NFPA 99, "15.7.4.3.1* Where buildings > are required to be subdivided into smoke compartments, fire alarm > notification zones shall coincide with one or more smoke compartment > boundaries or shall be in accordance with the facility fire plan.", it > appears to me that the correct answer to the first question is > "sprinkler zone", and the second question is "one sprinkler zone= one or > more smoke zones". > > Mark at Aero > 602 820-7894 > > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkl > er.org _______________________________________________ > Sprinklerforum mailing list > [email protected] > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkl > er.org > _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
