fire alarm system notification appliances chapter 13 page 394

Fire Alarm System Notification Appliances

Chapter 13

Page 394

2

Objectives

• Discuss the four groups of notification signals, explain why the temporal-coded signal is now the national standard signal, and outline research conducted with respect to recognition of the temporal-coded signal

• List the available types of audible notification appliances

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Objectives

• Evaluate public- and private-mode audibility requirements for fire alarm systems and explain why the two modes differ

• Determine the effectiveness of an audible notification appliance, given ambient sound levels, door or wall attenuation, and inverse square law losses

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Objectives • Compare wall-mounted and ceiling-

mounted visible notification appliance requirements

• Locate visible notification appliances in a room, corridor, or sleeping room

• Use the multiple-square layout to optimize visual notification appliance location

• Explain the function of an annunciator panel

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Objectives • Determine the reasons why tactile

notification appliances may be necessary, and discuss how they can be used effectively

• Compare NFPA 72, ANSI, UL, and ADA requirements for visible notification appliances

• Discuss the conditions that make strobe synchronization necessary

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Audible Notification Appliances

• Audible Notification Appliance Audibility Requirements

• Public-Mode Audibility Requirements (see Tables 13-1 and 13-2, Pages 399-400)

• Private-Mode Audibility Requirements• Audible Notification Appliance Intelligibility

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• Audible Notification Appliance Location (see Tables 13-3 and 13-4 Page 401)

• Inverse square law: as the distance from the ear to the notification appliance doubles, sound is reduced by 6 dB along the centerline of the notification appliance

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Figure 13-5. Illustration of the inverse square law; sound pressure reduces 6 dB every time the distance from the audible notification appliance doubles

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Figure 13-6. Off-centerline sound losses; persons “B” and “C” are at the same lineal distance from the notification appliance as person “A”

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Ex. 13-6: Calculation of Audible Notification Appliance Audibility

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“Exit Marking” Audible Notification Appliances

• “Exit marking” audible notification appliances: installed at the entrance of all building exits and areas of refuge– Emit distinct sound pressure levels capable of

directing occupants to the exits

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Visible Notification Appliances

• Candela (cd): the standard unit of light intensity measurement

• Blackbody: ideal body that would absorb all incident radiation and reflect none

• Public-Mode Visibility Requirements• ADAAG Visible Appliance Requirements• Private-Mode Visibility Requirements

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• Wall-Mounted Visible Notification Appliance Location

• Ceiling-Mounted Visible Notification Appliance Location (see Table 13-5, Page 410)

• Visible Appliance Spacing in Rooms That Are Not Square

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• Multiple Square Layout of Visible Notification AppliancesOptimization of Visual Notification Coverage

• Placement of Visible Appliances in Corridors (see Table 13-6, Page 415)

• Spacing of Visible Appliances in Sleeping Areas (see Table 13-7, Page 417)

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Figure 13-12. Optimization of visible notification coverage (part 1)

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Figure 13-12. Optimization of visible notification coverage (part 2)

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Figure 13-13. Corridor spacing of visible appliances

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• Combination Audible/Visible Notification Appliances

• Combination audible/visible notification appliance: has both audible and visible notification components

• Synchronization of Visible Appliances

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Textual Audible and Visible Notification Appliances

• Textual visible notification appliance provides alphanumeric fire alarm notification or instructions

• Usually on an annunciator, fire alarm control unit, or a panel remote from the main FACU

• Textual notification information can be provided by LEDs on a display window

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Textual Audible and Visible Notification Appliances

• Can provide more precise information than by other audible and visible appliances

• Can provide notification for persons with hearing disabilities

• Central station operators, security guards, and fire watch personnel often are provided with textual appliances

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Annunciation Notification Appliances

• Annunciator panel: provides visible notification of the location of an initiating device by zone and floor

• Annunciator should be placed in a fire control room or at main building entrance– Fire service personnel can identify fire location

and implement suppression strategy

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Tactile Notification Appliances

• Audible appliances are effective for those who can hear

• Visible appliances are effective for those who can see

• Combination audible/visible appliances are effective for those with either sense

• Tactile notification appliances are for individuals who can neither see nor hear

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• With tactile notification appliances, training must be provided so that occupants can find exit building on their own

• If this is not possible, a method must be provided for the notification of supervisory personnel who are responsible for assisting occupants to safety

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• Bed shakers are an alternative for rousing sleeping individuals

• Some tactile appliances, such as vibrating belt pagers, and variable-speed ceiling fans, cannot be readily supervised, and are therefore considered supplemental notification appliances

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Summary

• Notification appliances must be selected carefully to be congruent with the needs of – Building occupants– Supervisory personnel– Security personnel who interpret the alarm– Fire service responders

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Summary

• Notification appliances must– Accommodate persons with disabilities – Arouse a sleeping person – Spur a person who is awake to leave the

building or relocate to a fire-safe area

fire alarm system notification appliances chapter 13 page 394

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