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Smoke Detector Location
Smoke detectors should be installed in accordance with theNational FireProtection
Association
(NFPA)
Standard 74.
The following is from NFPA 74:
Smoke detectors shall
be
installed
outside
of
each
separate sleeping area in the immediate vicinity of the bedrooms and on each
additional story of the family living unit including basement and excluding crawl
spaces and unfinishedattics (see illustration below). For family living units with one
or more split levels (i.e., adjacent levels with with less than one full story separation
between levels), a smoke detector required by the above shall suffice for an adjacent
lower level, including basements.
EXCEPTION:
Where there is an intervening door between one level and the
adjacent lower level, a smoke detector shall be installed on the lower level.
Ceiling mounted smoke alarms should be located in the center of the room or hall,
not less than 4 inches from any wall. When the detector is mounted on a wall, the
top of the detector should be 4 to 12 inches from the ceiling.
Do not install smoke alarms where normal ambient temperatures are above
lOOoF
(37.8”C),
or below
40’F
(4’C).
Also, do not locate smoke detectors in front of air conditioners, heating registers,
or other locations where normal air circulation will keep smoke from entering the
detector.
Heat from a fire rises to the ceiling, spreads out across the ceiling surface and begins
to bank down from the ceiling. The comer where the ceiling and wall meet is an air
space into which heat has difficulty in penetrating. In most
fires,
this ‘dead’ air space
measures about 4 inches (O.lm) along the ceiling from the comer and 4 inches
(O.lm) down the
wall
as shown in the illustration below. Heat or smoke detectors
should not be placed in this ‘dead’ air space.” (See illustration on next page).
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