Kidde Fire Systems DS Series, Application Manual

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July 2016 -21- K-76-1000
Sloping Peaked-Typed Ceilings
In rooms with sloping peaked-type ceilings, place the first row of detectors within 3 ft. (1 m) (horizontally)
of the ceiling peak. Space additional detectors, if required, based upon the horizontal projection of the
ceiling and ceiling construction. This modification of spacing for smoke detectors on sloped ceilings is
identical to that used for spot-type heat detectors. Refer to Figure 5.
In rooms with sloping shed-typed ceilings having a slope:
•
Less than a 1 ft. in 8 ft. (1 m in 8 m) rise, treat as a level ceiling.
• Greater than a 1 ft. in 8 ft. (1 m in 8 m) rise, place the first row of detectors within 36 in. (910 mm) of
the high end of the ceiling. Space additional detectors, if required, based upon the horizontal projec-
tion of the ceiling and ceiling construction.
• Less than 30 degrees, adjust the horizontal spacing according to the height of the peak.
• Greater than or equal to 30 degrees, adjust the horizontal spacing according to the average sloped
ceiling height.
This spacing modification for smoke detectors on sloped ceilings is identical to that used for spot-type heat
detectors. Refer to Figure 6.
Under-Floor Installation
When spot-type smoke detectors are installed under raised floors, they are subjected to high air velocities
and dust levels. Install the detectors with the base up or the base vertical (never down) as shown in Figure
13 below. This minimizes the effects of dirt, dust, and mechanical interference from cabling.
Figure 13. Permissible Smoke Detector Placement Under Raised Floors
A. Junction box secured to
structure
B. Junction box secured to floor
support
C. Junction box secured to angle
iron or channel support
1. Raised floor panel
2. Smoke detector
3. Junction box 4. Steel angle or channel
support
5. EMT or FMC conduit
6. Clamp
1
2
2 2
3 3 4
5 5
5
5 6
A
C