Heat Alarms Recommended in New Home Construction
25 ft. | | 12.5 ft. |
(7.8 m) | | (3.8 m) |
| | | | | |
50 ft.
(15 m)
25 ft.
(7.8 m)
25 ft. | 25 ft. | 12.5 ft. |
(7.8 m) | (7.8 m) | (3.8 m) |
Heat Alarms should be mounted on the bottom of the joists and not up in the joist channels.
•The recommended location for a Heat Alarm is at the center of the ceiling. At this location, the Heat Alarm is closest to all areas of the room.
•If it is not practical to install the Heat Alarm in the center of the room, use an off-center location not less than 4 inches from the sidewall.
•If it is not practical to install the Heat Alarm on the ceiling, the next logical location is on a sidewall. A Heat Alarm mounted on a sidewall should have the top of the unit between 4 and 12 inches from the ceiling.
•The smooth ceiling distance between Heat Alarms shall not exceed spacings as determined by UL fire tests. This Heat Alarm has a 50 foot spacing.
•Reduced spacing may be required due to factors such as exposed joists, drafts, ceiling heights greater than 10 feet, and other structural characteristics that may affect Heat Alarm operation. Walls, partitions, doorways, and joists interrupt the normal flow of heat creating new areas to be protected.
NFPA Standard 72 Appendix A-2-5.2.2.2 part c-d
(c)The Spacing of Detectors: Where a room is too large for protection by a single detector, several detectors should be used. It is important that they be properly located so all parts of the room are cov- ered. (d) Where the Distance Between Detectors Should Be Further Reduced: The distance between detectors is based on data obtained from the spread of heat across a smooth ceiling. Where the ceiling is not smooth, the placement of the detector should be tailored to the situation.
For instance, with open wood joists, heat travels freely down the joist channels so that the maximum distance between detectors [50 ft (15 m)] may be permitted to be used. However, heat has trouble spreading across the joists, so the distance in this direction should be 1/2 the distance allowed between detectors, as shown in the illustration above (“Heat Alarms Recommended in New Home Construction”) and the distance to the wall is reduced to 12-1/2 ft. (3.8 m). Since 1/2 x 50 ft. (15 m) is 25 ft. (7.6 m), the distance between detectors across open wood joists should not exceed 25 ft. (7.6 m), as shown in “Heat Alarms Recommended in New Home Construction,” and the distance to the wall is reduced [1/2 x 25 ft. (7.6 m)] to 12.5 ft. (3.8 m). Paragraph 2-5.2.2.4 requires that detectors be mounted on the bottom of the joists and not up in joist channels.
Walls, partitions, doorways, ceiling beams, and open joists interrupt the normal flow of heat, thus creat- ing new areas to be protected.
Early warning detection is best achieved by the installation of fire detection equipment in all rooms and areas of the household as follows: A Smoke Alarm installed in each separate sleeping area (in the vicinity, but outside bed- rooms), and Heat or Smoke Alarms in the living rooms, dining rooms, bedrooms, kitchens, hallways, finished attics, furnace rooms, closets, utility and storage rooms, basements, and attached garages.
Additional local building and regulatory codes may apply in your area. Always check compliance require- ments before beginning any installation.
Specific requirements for Heat or Smoke Alarm installation vary from state to state and from region to region. Check with your local Fire Department for current requirements in your area. If you install AC or AC/DC units, it is recommended they be interconnected for added protection. Interconnect Smoke and Heat Alarms for added pro- tection.
LOCATIONS TO AVOID FOR HEAT ALARMS
This unit works best when it’s clean and nothing interferes with the sensor. If exposed to dirt, grease, extreme temperatures not caused by fire (especially in attics where daily temperatures can exceed the 135ºF (57ºC) alarm level or high humidity, it may sound “unwanted” alarms. If Heat Alarms are installed where heat can’t reach them–like in “dead air spaces” or near fans–they may not be able to provide an early enough warning in case of fire.
For best performance, do not install the Heat Alarm:
In a location where it could be easily triggered when using your remote to operate your TV, VCR, or other remote controlled appliances.
•Where temperatures are regularly below -20ºF (-29ºC) or above 115ºF (46ºC), including unheated buildings, outdoor rooms, or porches.
•Do not install a Heat Alarm directly over the stove or range. Clean a laundry room unit frequently to keep it free of dirt or lint.
•Near fresh air vents, ceiling fans, or in very drafty areas. Drafts can blow heat away from the unit, preventing it from reaching the sensing chamber.
•In “dead air” spaces. Install units according to “Avoiding Dead Air Spaces”.
•Less than 12 inches (305 mm) away from fluorescent lights. Electrical “noise” can interfere with the sensor.
AVOIDING DEAD AIR SPACES
“Dead air” spaces may prevent heat from reaching the Heat Alarm. To avoid dead air spaces, follow installation instructions in the “Recommended Locations for Heat Alarms” (refer to NFPA72 for details).
For wall mounting (if allowed by building codes), the top edge of Heat Alarms should be placed between 4 inches (102 mm) and 12 inches (305 mm) from the wall/ceiling line, below typical “dead air” spaces.
