108.411—Smoke detection system.
Each smoke accumulator in a smoke detection system must be located on the overhead of the compartment protected by the system in a location—
(a)
Where no portion of the overhead of the compartment is more than 12 meters (40 feet) from an accumulator;
(b)
That is no closer to the opening of a ventilator than 3 times the diameter or equivalent size of the opening.