Water allowance for private hydrant
Water allowance for private hydrant
(OP)
I have a question regarding water allowance for private hydrant.
According to NFPA 13, 11.1.6.2
Water allowance for outside hose shall be added to the sprinkler requirement at the city main or a private hydrant, whichever is closer to the system riser.
Project info.
5 stories office building.
A total of 4 private hydrant supplied by the same fire service.
so how much allowance i have to add to my overhead sprinkler calculation? 1250+100 gpm?
According to NFPA 13, 11.1.6.2
Water allowance for outside hose shall be added to the sprinkler requirement at the city main or a private hydrant, whichever is closer to the system riser.
Project info.
5 stories office building.
A total of 4 private hydrant supplied by the same fire service.
so how much allowance i have to add to my overhead sprinkler calculation? 1250+100 gpm?





RE: Water allowance for private hydrant
Out of curiosity, how where did the 1250 come from?
R/
Matt
RE: Water allowance for private hydrant
RE: Water allowance for private hydrant
RE: Water allowance for private hydrant
It sounds like you are in CA with the 1250 requirement.
For the sprinkler system, you calculate the flow from the design area + the hose allowance based on hazard. Office is typical light hazard which is 100 gpm.
So total demand = sprinklers + 100. The 100 gpm is added at the hydrant nearest to the base of the riser.
With a five story building, you also likely have manual wet standpipes. You don't have hose or sprinkler demand to the standpipe systems.
Travis Mack
MFP Design, LLC
www.mfpdesign.com
"Follow" us at https://www.facebook.com/pages/MFP-Design-LLC/9221...
RE: Water allowance for private hydrant
What's needed to answer your question are: classification of occupancy group, construction classification of the building, ground floor square footage and duration of water supply.