Fire alarm 2_b_heat detectors

1. Initiating Devices
 17.1 Application
 17.2 Purpose
 17.3 Performance-Based Design
 17.4 General Requirements
 17.5 Requirements of Smoke & Heat
Detectors
17.6 Heat-Sensing Fire Detectors
17.7 Smoke Detecting Fire Detectors
NFPA 72 Chapter 17

2. Initiating Devices
17.6 HEAT-SENSING FIRE DETECTORS
– Installed in all areas required by codes or AHJ
17.6.2 TEMPERATURE CLASSIFICATION
17.6.2.2.1 COLOR CODING
5.6.2.1.1 Heat detectors marked IAW Table 17.6.2.1
17.6.2.2.1.2(2) Alternate means of marking; rings or
3/8” numerals
17.6.3.6 Heat detectors integral to smoke detectors
to be listed for 50’ spacing
17.6.2.2.2.1 Marked for temperature
17.6 Heat-Sensing Fire Detectors

3. Initiating Devices
17.6.3.1.3 LOCATION
17.6.3.1.3.1 Unless modified by 17.6.3.2.2 or
17.6.3.3.2 or 17.6.3.7
17.6.3.1.3.2 Line-type located on ceiling or not more
than 20” down sidewall (Exc.)
17.6.2.3* Ambient Ceiling Temperature
– Select detectors w/ Table 17.6.2.1 >20º F
maximum expected ceiling temperature
17.6 Heat-Sensing Fire Detectors

4. Initiating Devices
17.6.3 Location and Spacing
17.6.3.1 Smooth Ceiling Spacing
17.6.3.1.1 One of the following applies:
– The distance between detectors shall not
exceed their listed spacing,
– partitions within 15” of ceiling or;
– < .70S to all points
17.6.3.1.2 IRREGULAR AREAS
– Max spacing is allowed to be exceeded
provided max. distance to wall not greater than
0.7S x listed spacing
17.6 Heat-Sensing Fire Detectors

5. Initiating Devices
SOLID JOIST CONSTRUCTION = >4” & <3’ on center
17.6.3.2 SOLID JOIST CONSTRUCTION
– Where measured at right angles to joist use
50% of listed spacing
BEAM CONSTRUCTION = >4” & >3’ on center
17.6.3.3 BEAM CONSTRUCTION
– For beam <4” --> smooth ceiling spacing
– For beam >4” --> 2/3 smooth ceiling spacing
– For beam >18” & >8’ on center --> in the bay
17.6 Heat-Sensing Fire Detectors

6. Initiating Devices
17.6.3.4 SLOPING CEILINGS
17.6.3.4.2.1 PEAK
– A row of detectors within 3’ of the peak
17.6.3.4.1.1 Roof slopes
• < 30 degrees --> spacing IAW peak height
• > 30 degrees --> spacing IAW average
across slope
17.6 Heat-Sensing Fire Detectors

7. Initiating Devices
17.6.3.5 HIGH CEILINGS
17.6.3.5.1 10’-30’ spacing reduced IAW Table
17.6.3.5.1
17.6.3.5.2 Minimum spacing not required to be < .4H
17.6 Heat-Sensing Fire Detectors
Spacing Exercise