Spray Booths

[MitchellCons]

I have a question, are sprinklers always required at the top of the exhaust duct out the top of a spray booth or can we install a sprinkler just over the fan motor if the motor sits right on top of the booth itself? Everything I find in NFPA 13 leads me to believe that sprinklers are always required at the top. But I have personly seen designs and installations that provide sprinklers over the fan motor only when the motor is on the top of the booth and not @
the roof.

Thanks for your help in advance

 

[FFP1]

FM standards require a single sprinkler near the top of the exhaust ductwork. This requirement is based on the loss history. These ducts will eventually accumulate combustible residue; any fire involving the combustible accumulation inside the duct is very difficult to extinguish via manual fire fighting efforts. One sprinkler near the top of the ductwork has proven to be very effective in controlling the fire and reducing damage (primarily due to heat and smoke).

I would assume NFPA standards also require this approach, but I am not sure where this is addressed by NFPA; most of my customers request the application of FM Standards for spray booths.

 

[MitchellCons]

FFP1, thanks but does the FM standard say spray booth exhaust ducts or does the standard leave it open to all exhaust ducts? Does it matter if it's a spray booth or not?