It is usually in your local building code. For example, it is located in the 2015 international building code chapter 9, 903.4.2. Check the exceptions to see if you need one.
James is correct. It is also in the same section of the fire code, and requires an approved audible device located on the exterior of the building in an approved location. In my jurisdiction, the AHJ typically requires it on the address facing wall of the building.
Above the FDC. Some AHJ are replacing bells with horn strobes and color coding the lens to blue or red if the clear is being used to signify FACP annunciator location.
- mostly Chicago suburbs
From an AHJ perspective, I have always preferred that the waterflow alarm be both audible and visual (but it doesn't need to be a "strobe" light). The device should be located above and in close proximity to the fire department connection. This assists responding firefighters in locating the FDC.
As indicated above the location(s) and types of these devices are dependent on the AHJ where I am we have 5 AHJ and each has some requirement that's different.
Is it for a building located within a city (outside wall of a supermarket, office building...) or for buildings inside an industrial facility ?
In the first case, it is interesting to have this external alarm (gong) as it will indicate that there is a fire and people passing by can alert the fire department. In addition, the fire department may use the gong to quickly determine which sprinkler system is concerned and where to possibly connect to the FDC.
In the case of an industrial building, it could be the same (gives a local alarm and people can alert accordingly) but might not be absolutely necessary where the plant is occupied 24/7 and alarms from the sprinkler systems are reported to a constantly attended location.
In NFPA 13 (2019 Edition), it is indicated : §A.18.104.22.168 Outside alarms might not be necessary where the sprinkler system is used as part of a central station, auxiliary remote station, or proprietary signaling fire alarm system, utilizing a listed audible inside alarm devices.
Regarding the position, it is only indicated (§A.22.214.171.124) that the alarm apparatus should located and installed so that all parts are accessible for inspection, removal and repair and that the motor gong bell mechanism should be protected from weather related elements such as rain, snow or ice. It should also be protected from other exposures, such as birds, small animals that could make a nest in the bell, mechanical damages, possible vandalism...
There is no requirement in the standard to provide it close to the FDC, but it could be a local requirement from the AHJ.
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