The distance between smoke detectors shall not exceed a nominal spacing of 30 feet and there shall be detectors within a distance of one-half the nominal spacing , measured at right angles from all walls or partitions extending upward to within the top 15 percent of the ceiling height.
How far down from the ceiling should a smoke detector be placed?
Wall-mounted alarms should be installed not more than 12 inches away from the ceiling (to the top of the alarm). If you have ceilings that are pitched, install the alarm within 3 feet of the peak but not within the apex of the peak (four inches down from the peak).
Does ceiling height affect smoke detector spacing?
For level ceilings, NFPA 72 currently requires spacing smoke detectors at one half their listed spacing , perpendicular to the run of the beams on a ceiling less than or equal to 12 feet in height, when the beams are less than or equal to 12 inches deep. ... Ceilings with beams and joists affect detector spacing.
Can you mount a smoke detector vertically?
Tray Shaped Ceilings: Smoke alarms or smoke detectors shall be installed on the highest portion of the ceiling or on the sloped portion of the ceiling within 12 in . (305mm) vertically down from the highest point.
Do smoke alarms need to be ceiling mounted?
Smoke alarms should be installed at least 10 feet (3 meters) from a cooking appliance to minimize false alarms when cooking. Mount smoke alarms high on walls or ceilings (remember, smoke rises). Wall-mounted alarms should be installed not more than 12 inches away from the ceiling (to the top of the alarm).
What is the 0.7 rule?
NFPA 72 requires that all points on the ceiling have a detector within a distance of 0.7 times the listed spacing of the detector . This ensures that when detection is used, the entire space on the ceiling is covered by detection. This requirement is commonly called the Point 7 (0.7) Rule.
How many smoke detectors can you have in one zone?
The maximum number of smoke alarms that should be interconnected per NFPA 72 standards is 12 . Always make sure the smoke alarms you are interconnecting are compatible. In addition to the 12 smoke alarms in the series, you can connect up to 6 compatible devices like door closers, bells, or lights.
Where should smoke alarms not be placed?
Where the temperatures are regularly below 40°F (4° C) or above 100° F (38° C) including unheated buildings, outdoor rooms, porches, or unfinished attics or basements. In very dusty, dirty, or greasy areas. Do not install a Smoke Alarm directly over the stove or range.
How close should a smoke detector be to a bedroom door?
The locations for ceiling-mounted smoke detectors installed on a smooth ceiling for a single or double doorway must match the centerline of the doorway no more than five feet from the door and no closer than 12 inches to the doorway .
How close can a smoke detector be to a wall?
If you mount it on the wall, place it four to 12 inches below the ceiling and away from corners. Keep them high because smoke rises. Never place them any closer than three feet from an air register that might re-circulate smoke. Don’t place them near doorways or windows where drafts could impair the detector operation.
Why are smoke detectors on the ceiling?
Ceiling mounting it is typically preferred as it allows the smoke alarm to be placed more centrally in the room .
Where should smoke detectors be placed on ceiling?
Make sure smoke detectors are installed high on the walls or near the center of the ceilings , and at least 10 feet away from cooking appliances. When installing on the wall, place the smoke alarm at least 12 inches from the ceiling. This is because smoke rises and will make the alarms the most effective.
What should be done when the smoke alarm emits a continuous signal?
You should hear the signal immediately. To check if the smoke alarm detects smoke properly, extinguish a candle near it . You must leave immediately and call the fire department from a safe location. Ensure that all the occupants have evacuated the dwelling or house.
How much area does a heat detector cover?
For smoke detectors, the individual coverage can be represented by a square measuring 10.6m x 10.6m giving a coverage of 112m2 per device, which is usually approximated to 100m2. With heat detectors this figure is 7.5m x 7.5m, giving an area of coverage of 56m2 per device which is rounded down to 50m2.
What is the primary purpose of a duct detector?
The primary purpose of duct smoke detection is to prevent injury, panic, and property damage by reducing the spread (recirculation) of smoke . The detector samples air currents passing through a duct and gives dependable performance for management of smoke and combination fire smoke dampers.
What is the coverage of a smoke detector?
In compliance with the National Fire Protection Association (NFPA), smoke alarms will cover a radius of 21 feet, and an area of coverage of 1,385 square feet . The maximum distance between two smoke alarms should be 30 feet.
