NFPA 13 - Area of Demand
NFPA 13 - Area of Demand
(OP)
In a question related to my recent thread in regarding Water Demand, can anyone give me an idea about how to select an area of demand?
The project I'm working on has a total area of more than 10,000 sq feet (but less than 25,000 sq ft), laid out in an H-pattern (i.e. resembling the letter H). It is highly unlikely that a fire would engulf the entire area unless the fire suppression system did not work, and even then...not likely.
It is more likely that a fire would be limited to one of the upright branches of the "H" (roughly 3,000 sq ft) or even half of one of the upright branches (1,500 sq ft). I am tempted to use an Area of Demand of 3,000 sq ft, but would like to have a more firm resolution that that is the correct area to use.
The NFPA 13 standard seems rather vague on the issue. I have old (+/- 15 years) Factory Mutual data sheets indicating I should be using 3000-4000 sq ft for my Area of Demand.
Anyone have any experience with this kind of design? I could provide more information if necessary.
Cheers,
CanuckMiner
The project I'm working on has a total area of more than 10,000 sq feet (but less than 25,000 sq ft), laid out in an H-pattern (i.e. resembling the letter H). It is highly unlikely that a fire would engulf the entire area unless the fire suppression system did not work, and even then...not likely.
It is more likely that a fire would be limited to one of the upright branches of the "H" (roughly 3,000 sq ft) or even half of one of the upright branches (1,500 sq ft). I am tempted to use an Area of Demand of 3,000 sq ft, but would like to have a more firm resolution that that is the correct area to use.
The NFPA 13 standard seems rather vague on the issue. I have old (+/- 15 years) Factory Mutual data sheets indicating I should be using 3000-4000 sq ft for my Area of Demand.
Anyone have any experience with this kind of design? I could provide more information if necessary.
Cheers,
CanuckMiner





RE: NFPA 13 - Area of Demand
RE: NFPA 13 - Area of Demand
The area is a maintenance shop to be constructed in an underground mine (i.e. located with hard rock walls, ceiling, and floor). The spaces will be mostly open, but could contain vehicles at times. There are limited stockpiles of flammable and/or combustible materials.
I am hesitant to use the entire area of the shop to base my water demand on as this would subsequently require a large, dedicated volume of water to be supplied. If I am going to tell the Owner that he is to provide such a large volume of water (and the facilities to deliver it) I need to be able to back it up (e.g. point to a particular section of a standard or code). Also, in my case, I just can't picture the entire shop engulfed in a fire.
I suppose it is one of those things that must be determined by judgement and experience. Thanks again for sharing yours with me.
Cheers,
CanuckMiner
RE: NFPA 13 - Area of Demand
James D. Kieffer, PE
Kieffer & Associates Inc.
www.kiefferassociates.com