The 7th floor demand is 285 GPM @ 66 PSI. I have a remote area on floor 7 that requires 12 heads be flowing. There is a chance I can upsize the riser and main to that area to satisfy the demand without a pump. I’m still working on options.
The main purpose of this inquiry was to make sure I could separate the level 1 demand from the possible fire pump sizing for level 7, which sounds like it is possible if I provide a separate feed to the dry valve after the backflow but before the pump suction. Jeff Brickell, CET Senior Estimator/Designer NICET III CERTIFIED CERT #147245 OREGON CERTIFIED COBID FIRM #13272 (EMERGING SMALL BUSINESS) TRIAD FIRE PROTECTION [cid:[email protected]] OREGON . WASHINGTON . ARIZONA OFFICE 503.856.6333 CELL 602.550.4292 FAX 866.766.8862 From: Fpdcdesign <[email protected]> Sent: Tuesday, November 19, 2024 8:21 AM To: Discussion list on issues relating to automatic fire sprinklers <[email protected]> Subject: [Sprinklerforum] Re: Fire Pump Sizing Todd G Williams, PE Fire Protection Design/Consulting Stonington, CT 860-535-2080<tel:860-535-2080> (ofc) 860-554-7054<tel:860-554-7054> (fax) 860-608-4559<tel:860-608-4559> (cell) On Nov 19, 2024 at 10:03 AM, <Jeff Brickell<mailto:[email protected]>> wrote: A couple of points here: 1. You do not say where the demand points are located. I have to make assumptions that the garage is probably at the dry valve or whatever system control. Is the 7th floor demand taken at the floor control on the 7th floor? What is the actual demand at the BoR or location close the garage connection? Correct, the garage is served by a dry valve in the fire pump room. The demands are at B.O.R. The 7th floor is a combination standpipe and the demand is at the B.O.R. of the standpipe riser in the fire pump room on level 1. The actual demand is 385 GPM plus the 250 Hose Demand. So based on this and your first email, your 7th floor sprinkler demand, with hose stream, is 635 gpm at 66 psi at the manifold on the 1st floor. This cannot be provided by the public water. However, the 1st floor garage demand is 635 gpm at 61 psi at the manifold, which the city demand can provide. Wouldn’t it be easier and cheaper to modify the 7th floor sprinklers so that the demand can be met by the city? Todd G Williams, PE Fire Protection Design/Consulting Stonington, CT 860-535-2080<tel:860-535-2080> (ofc) 860-554-7054<tel:860-554-7054> (fax) 860-608-4559<tel:860-608-4559> (cell) On Nov 19, 2024 at 9:06 AM, <Jeff Brickell<mailto:[email protected]>> wrote: I have a situation that’s unique to me and am looking for some guidance. I have a 7-story building. The first level contains a parking garage with a demand of 635 GPM @ 61 PSI. The municipal supply can meet this demand. The 7th floor has a remote area with a demand of 285 GPM @ 66 PSI, which the municipal supply cannot meet. NFPA 20 says to size a fire pump to meet the greatest demand. If I can meet the level 1 demand without a pump, why would I need to size a fire pump for it? There would be a drastic size reduction if I only had to meet the 7th floor demand. I have reached out to a couple other people, and they have all said I need to size the pump to the garage demand, I am just curious as to why. If the contractor were to tee the underground and bring up a second supply for the first floor only would that be acceptable to then not use a pump? Maybe there is something I’m not considering or thinking of since this is new to me. Any advice, comments welcome, thank you. Jeff Brickell, CET Senior Estimator/Designer NICET III CERTIFIED CERT #147245 OREGON CERTIFIED COBID FIRM #13272 (EMERGING SMALL BUSINESS) TRIAD FIRE PROTECTION [cid:[email protected]] OREGON . WASHINGTON . ARIZONA OFFICE 503.856.6333 CELL 602.550.4292 FAX 866.766.8862 _________________________________________________________ SprinklerForum mailing list: https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org To unsubscribe send an email to [email protected]<mailto:[email protected]> _________________________________________________________ SprinklerForum mailing list: https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org To unsubscribe send an email to [email protected]<mailto:[email protected]>
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