sprinklerdesigner
Mechanical
- Sep 8, 2006
- 10
I already know the answer to this but I am locking horns with one of the AHJ's and was wondering if anyone knows of a more definitive article somewhere.
I have a motel with corridors 5' wide x 150' long giving a compartment size of 750 sq. ft..
The corridor ceilings are smooth, flat and the ceiling height is 9'-0".
For these corridors I elected to utilize residential sprinklers spaced 20' on centers for the corridors. In accordance with their listing which requires four sprinklers be calculated which, when spaced 20', require a discharge of 20 gpm. As each head covers 100 sq. ft. at 20 gpm I exceed the required density of .10.
As stated the local AHJ has a problem with me calculating only four sprinklers wanting me to calculate 5 heads per NFPA 13 since I am outside the dwelling unit and the "compartment" exceeds 500 sq. ft..
6.6.7.2.2 Residential sprinklers shall be permitted to be used in corridors leading to dwelling units and in areas covered by 6.7.2.2, 6.7.2.3 and 6.7.3.3.
6.7.2.2 The system demand of areas outside the dwelling unit shall be permitted to be limited to the number of sprinklers in the compartmented area but shall not be greater than the demand for a total of four sprinklers where all of the following conditions are met:
(1) The area is compartmented into areas of 500 ft2 (46 m2) or less by 30-minute fire-rated construction.
(2) The area is protected by quick-response or residential sprinklers not exceeding 130 ft2 (12 m2) per sprinkler for ordinary hazard, 225 ft2 (20.9 m2) for light hazard, or the allowable coverage of the sprinkler listing.
(3) Openings have a lintel at least 8 in. (203 mm) in depth.
(4) The total area of openings does not exceed 50 ft2 (4.6 m2) for each compartment.
(5) Discharge densities are in accordance with NFPA 13, Standard for the Installation of Sprinkler Systems.
This is followed by:
6.7.2.3 The following types of spaces are permitted to be protected by residential sprinklers where they have flat, smooth ceilings not exceeding 10 ft (3.0 m) in height and are protected in accordance with the requirements for residential sprinklers:
(1) Lobbies not in hotels and motels
(2) Foyers
(3) Corridors
(4) Halls
(5) Lounges
(6) Other areas with fire loads similar to residential
To further substantiate the four sprinkler design is adequate I submitted this ROP from the NFPA website.
Here is a copy if you don't want to sift through the pdf file:
It is obvious, with 23 members out of 23 members voting in the affirmative to accept this proposal, the committee's intention was to require only four heads be calculated in corridors when residential heads are used and the requirements of 6.7.2.3 as to residential like occupancies, ceiling heights and ceiling construction.
The problem I am having is the local AHJ is interpreting the 500 sq. ft. compartment limitation contaned in 6.7.2.2 also applies to 6.7.2.3 which it doesn't.
Does anyone know of any sources that might clear it up for the local AHJ?
I have a motel with corridors 5' wide x 150' long giving a compartment size of 750 sq. ft..
The corridor ceilings are smooth, flat and the ceiling height is 9'-0".
For these corridors I elected to utilize residential sprinklers spaced 20' on centers for the corridors. In accordance with their listing which requires four sprinklers be calculated which, when spaced 20', require a discharge of 20 gpm. As each head covers 100 sq. ft. at 20 gpm I exceed the required density of .10.
As stated the local AHJ has a problem with me calculating only four sprinklers wanting me to calculate 5 heads per NFPA 13 since I am outside the dwelling unit and the "compartment" exceeds 500 sq. ft..
6.6.7.2.2 Residential sprinklers shall be permitted to be used in corridors leading to dwelling units and in areas covered by 6.7.2.2, 6.7.2.3 and 6.7.3.3.
6.7.2.2 The system demand of areas outside the dwelling unit shall be permitted to be limited to the number of sprinklers in the compartmented area but shall not be greater than the demand for a total of four sprinklers where all of the following conditions are met:
(1) The area is compartmented into areas of 500 ft2 (46 m2) or less by 30-minute fire-rated construction.
(2) The area is protected by quick-response or residential sprinklers not exceeding 130 ft2 (12 m2) per sprinkler for ordinary hazard, 225 ft2 (20.9 m2) for light hazard, or the allowable coverage of the sprinkler listing.
(3) Openings have a lintel at least 8 in. (203 mm) in depth.
(4) The total area of openings does not exceed 50 ft2 (4.6 m2) for each compartment.
(5) Discharge densities are in accordance with NFPA 13, Standard for the Installation of Sprinkler Systems.
This is followed by:
6.7.2.3 The following types of spaces are permitted to be protected by residential sprinklers where they have flat, smooth ceilings not exceeding 10 ft (3.0 m) in height and are protected in accordance with the requirements for residential sprinklers:
(1) Lobbies not in hotels and motels
(2) Foyers
(3) Corridors
(4) Halls
(5) Lounges
(6) Other areas with fire loads similar to residential
To further substantiate the four sprinkler design is adequate I submitted this ROP from the NFPA website.
Here is a copy if you don't want to sift through the pdf file:
It is obvious, with 23 members out of 23 members voting in the affirmative to accept this proposal, the committee's intention was to require only four heads be calculated in corridors when residential heads are used and the requirements of 6.7.2.3 as to residential like occupancies, ceiling heights and ceiling construction.
The problem I am having is the local AHJ is interpreting the 500 sq. ft. compartment limitation contaned in 6.7.2.2 also applies to 6.7.2.3 which it doesn't.
Does anyone know of any sources that might clear it up for the local AHJ?