NFPA Sprinkler Help - anyone?

[Raanne]

I'm trying to get the water demand requirements, and from what i can tell in 11.2.3.1.1, it says to add the hose stream from table 11.2.3.1.1 to the water supply for the sprinklers. For the hose stream demand, is this the combined inside and outside hose? and if so, is this the same universally (depending on hazard ratings of course - but i mean, are all light hazard hose requirements 100gpm?)

/new to fire protection stuff...

 

[cowboy41]

I'm trying to get the water demand requirements, and from what i can tell in 11.2.3.1.1, it says to add the hose stream from table 11.2.3.1.1 to the water supply for the sprinklers. For the hose stream demand, is this the combined inside and outside hose? and if so, is this the same universally (depending on hazard ratings of course - but i mean, are all light hazard hose requirements 100gpm?)
/new to fire protection stuff...

The most common method for determining your system demand is the density / area curve method in section 11.2.3.1.1 (1) and table 11.2.3.1.1.

Determine your hazard class Light, Ordenary group 1 or 2 or Extra group 1 or 2.

The min. design area for light and ordinary hazards is 1,500 sq. ft. and 2,000 for extra hazard.

1500 X .10 = 150 GPM plus 100 GPM for total hose stream….250 GPM

1500 X .15 = 225 GPM plus 250 GPM for total hose stream…..475 GPM

1500 X .20 = 300 GPM plus 250 GPM for total hose stream…..550 GPM

And so on.

Remember if it is a dry system to add 30 percent to your design area and if you have sloped ceilings or roof decks you need to add an additional 30 percent to your design area. (11.2.3.2.4)

You can also take a reduction for quick response heads based on you ceiling height.

Are you sizing an underground?

If you are sizing underground piping, I would use the pipe schedule method keeping in mind you available city pressures.

Good luck.