Kidde Fire Systems DS Series, Application Manual

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July 2016 -23- K-76-1000
Smoke Detector High Air Movement
The use of spot-type smoke detectors in areas of high air movement (greater than 300 ft./min [1.5m/sec])
requires a suitable reduction in detector spacing to maintain detector performance. Use the table below to
determine the reduced detector spacing in these areas. This table is not valid for use under floor or in
ceiling plenum areas, however, the principle of reduced spacing in these high-velocity areas applies.
Effects of Heating, Ventilating, and Air Conditioning (HVAC) Systems
Because airflow is critical to the transportation of smoke to the detector location, never locate smoke
detectors closer than 36 in. (910 mm) to an HVAC supply diffuser or return air opening. Higher velocity
intake and return grills may require additional clearance.
Note: Do not rely on the operation of the HVAC system when spacing smoke detectors.
Table 2. High Airflow Area Detector Spacing Reduction
Minutes per air
change Number of air
changes per hour Coverage per
detector
1 60
125 ft.
2
(12 m
2
)
2 30
250 ft.
2
(23 m
2
)
3 20
375 ft.
2
(35 m
2
)
4 15
500 ft.
2
(46 m
2
)
5 12
625 ft.
2
(58 m
2
)
6 10
750 ft.
2
(70 m
2
)
7 8.6
875 ft.
2
(81 m
2
)
8 7.5
900 ft.
2
(84 m
2
)
9 6.7
900 ft.
2
(84 m
2
)
10 6
900 ft.
2
(84 m
2
)