Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations 3DDave on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

NFPA 13R Density required outside the living units in a common area when using listed residential sprinklers.

SprinklerDesigner2

Mechanical
Nov 30, 2006
1,272
I have a three story apartment building where the architect of record specifically called for a system designed per NFPA 13R and not NFPA #13.

We have a common corridor where I used Tyco TY2325 listed residential dry sidewall sprinklers as the corridor is open at each end.

https://docs.johnsoncontrols.com/tycofire/api/khub/documents/0a1KMdxZ8MmPhOayZdbpaQ/content

The maximum area of coverage is 16'-0" x 8'-0" for 128 sq ft.

As the deflector is 4" to 6" below the ceiling I used a discharge of 18.0 gpm which meets the the head listing AND at 18 gpm also delivers a minimum density greater than 0.10 gpm over the area of coverage which is 128 sq ft.

My question is the "density" that need to be used.... do I use a .05 gpm per NFPA #13R or .10 gpm in accordance with NFPA #13?

As the building is defined by the architect of record as a NFPA #13R and NOT NFPA #13 all I need to do is meet the listing of 18 gpm and the density of .10 gpm doesn't even enter the picture. Am I correct?
 
Replies continue below

Recommended for you

That area is outside the dwelling unit. Therefore, you go to NFPA 13 for sprinkler spacing, area of coverage limits, obstruction rules and density of discharge. Since you are using residential sprinklers, you would do the greater of the listing or the actual area of coverage x 0.1. This is just as if you had a common lobby in a small hotel, or a storage closet in the back of house areas. You apply the density and area of coverge / spacing per NFPA 13. Note, you are not required to follow the criteria about protection of concealed combustible spaces outside the dwelling units. It's just spacing, density, obstructions and area of coverage.
 

Part and Inventory Search

Sponsor