We have an NFPA 13 system, using residential sprinklers, in a dwelling unit that has 2-levels of smooth flat ceilings. There are two levels of ceilings (9'-0" on left, 8'-0" height on right).
Image provided below:
Sprinklers are hydraulically calculated at their listing with a 20 x 20 spacing, and there is not an issue providing 0.10 gpm/sqft.
See the spacing above - is this an allowable arrangement though considering how it was calculated?
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5/18/2023 06:51:29 am
It looks ugly, but it's fine.
5/18/2023 09:00:41 am
I'm wrong, Anthony's right. Unless listed otherwise, residential heads are to be within 1" to 4" deflector to ceiling.
5/18/2023 07:01:16 am
This is not an appropriate lay out of sprinklers unless the sprinklers are allowed to be 12'' down from ceiling. In many cases pendant res sprinklers are only allowed to be 8'' maximum down from ceiling per their listing. Thus the area 3' left from the edge of the step in ceiling height is in an unprotected area.
5/18/2023 11:25:40 am
I agree with Anthony (and Pete's revised comment): Residential sprinklers don't have an equivalent to 18.104.22.168.1.3(b) (NFPA 13-16). I'm guessing this is because of the high wall wetting requirement for residential sprinklers.
5/18/2023 08:13:46 am
i would add another sprinkler 2' left of the center line. your chandelier or ceiling fan at the high ceiling won't be a problem and you solve the question of coverage... and it will look nicer.... I'm assuming you will be installing concealed flush and not dropped sprinklers... please. ...
5/18/2023 11:01:14 am
As indicated above, the possible issue is that a fire originating under the 9 ft ceiling, but at the edge with the 8 ft ceiling will first only operate the sprinkler under the 9 ft ceiling, with 3 ft not correctly covered… until the sprinkler under the 8 ft operates.
5/18/2023 11:06:07 am
Note that this would have been a lesser reliability issue if the sorinkler located 13 ft from the edge would have been the one under the 8 ft ceiling.
5/19/2023 07:21:30 am
That section is for standard spray sprinklers only and doesn't apply here. See comments above.
5/23/2023 08:04:23 am
Yes, that's for standard sprinklers but reference to NFPA 13-2019 section 22.214.171.124.2 (1) sprinklers shall be in accordance with 126.96.36.199, table 188.8.131.52.2 and figure 184.108.40.206.2 (a)
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