In my January 2024 web exclusive, I tackled questions often raised by those in the field trying to understand the requirements that affect their fire alarm system installations. Let’s take a look at some more of your questions.

Where can I find information on the proper location for strobes?

NFPA 72-2022, National Fire Alarm and Signaling Code, devotes a significant portion of Chapter 18, Notification Appliances, to answering this question. The Code offers so much material on this subject that we cannot possibly reproduce all of it in this limited amount of space. However, please take note of these key sections:

• 18.1 Application
• 18.2 Purpose
• 18.3 General
• 18.5 Visible Characteristics - Public Mode
• 18.6 Visible Characteristics - Private Mode
• 18.7 Supplementary Visible Signaling Method
• 18.9 Textual Visible Appliances

You will find detailed information on where to locate visible notification appliances in 18.5.5.7, Spacing in Rooms.

“18.5.5.7.1 Spacing shall be in accordance with either Table 18.5.5.7.1(a) and Figure 18.5.5.7.1 or Table 18.5.5.7.1(b).

“18.5.5.7.2 Visual notification appliances shall be installed in accordance with Table 18.5.5.7.1(a) or Table 18.5.5.7.1(b) using one of the following:

(1)  A single visual notification appliance.

(2)  Two groups of visual notification appliances, where visual notification appliances of each group are synchronized, in the same room or adjacent space within the field of view. This shall include synchronization of visual appliances operated by separate systems.

(3)  More than two visual notification appliances or groups of synchronized appliances in the same room or adjacent space within the field of view that flash in synchronization.

“18.5.5.7.3 Room spacing in accordance with Table 18.5.5.7.1(a) and Figure 18.5.5.7.1 for wall-mounted appliances shall be based on locating the visual notification appliance at the halfway distance of the wall.

“18.5.5.7.4 In square rooms with appliances not centered or in non-square rooms, the effective intensity (cd) from one wall mounted visual notification appliance shall be determined by maximum room size dimensions obtained either by measuring the distance to the farthest wall or by doubling the distance to the farthest adjacent wall, whichever is greater, as required by Table 18.5.5.7.1(a) and Figure 18.5.5.7.1.

“18.5.5.7.5 If a room configuration is not square, the square room size that allows the entire room to be encompassed or allows the room to be subdivided into multiple squares shall be used.

“18.5.5.7.6 If ceiling heights exceed 30 ft (9.1 m), ceiling mounted visual notification appliances shall be suspended at or below 30 ft (9.1 m) or at the mounting height determined using the performance-based alternative of 18.5.5.7, or wall mounted visual notification appliances shall be installed in accordance with Table 18.5.5.7.1(a).”

Additional information is provided in Annex A:

“A.18.5.5.5.7 The visual notification appliance intensities listed in Table 18.5.5.5.1(a) or Table 18.5.5.5.1(b), 18.5.5.6, or Table 18.5.5.8.3 or determined in accordance with the performance requirements of 18.5.5.7 are the minimum required intensities.

“It is acceptable to use a higher intensity visual notification appliance in lieu of the minimum required intensity. Areas large enough to exceed the rectangular dimensions given in Figure A.18.5.5.5(a) through Figure A.18.5.5.5(c) require additional appliances. Often, proper placement of appliances can be facilitated by breaking down the area into multiple squares and dimensions that fit most appropriately [see Figure A.18.5.5.5(a) through Figure A.18.5.5.5(d)]. An area that is 40 ft (12.2 m) wide and 80 ft (24.4 m) long can be covered with two 60 cd appliances. Irregular areas and areas with dividers or partitions need more careful planning to make certain that at least one 15 cd appliance is installed for each 20 ft × 20 ft (6.1 m × 6.1 m) area and that light from the appliance is not blocked.

“A.18.5.5.7.1 In rooms with an average ambient level greater than 500 lx, visual notification appliance spacing should be reduced by 30 percent (i.e., listed spacing × 0.7) or the required effective candela should be increased by 100 percent (i.e., effective candela × 2.0). Ambient light levels have an effect on the proper candela ratings in indirect viewing of visual notification appliances. The amount of ambient light is normally from two sources: artificial lighting and natural light from outside. In rooms or areas requiring artificial illumination, the ambient lux value for selecting candela values should be based on the maximum light intensity that the artificial light sources provide. In rooms or areas that have natural outside light, the ambient lux value should be that of the maximum light level with the shades or curtains fully open during daylight hours and with the artificial lighting illuminated. Ambient light can be measured using a calibrated light meter in the approximate center of the room, 4 ft (1.2 m) above the floor, with the sensor facing upward. The light meter should measure light level from 0 to 10,000 lx with a precision accuracy of +/-5 percent. For design purposes, typical ambient illumination for various locations and activities are shown in Table A.18.5.5.5.1 and can be used as a guide for the selection of appropriate visual signal intensity.

“A.18.5.5.7.2(2) The field of view is based on the focusing capability of the human eye specified as 120 degrees in the Illuminating Engineering Society (IES) Lighting Handbook Reference and Application. The apex of this angle is the viewer’s eye. In order to ensure compliance with the requirements of 18.5.5.5.2, this angle should be increased to approximately 135 degrees. Testing has shown that high flash rates of high-intensity visual notification appliances can pose a potential risk of seizure to people with photosensitive epilepsy. To reduce this risk, more than two visual notification appliances are not permitted in any field of view unless their flashes are synchronized. This does not preclude synchronization of appliances that are not within the same field of view.”

When does an owner need to provide a voice evacuation system?

First of all, you must make a distinction between a protected premises fire alarm system that uses the sound of the human voice to effect total evacuation of a building, and a building that will employ partial or selective evacuation, thus requiring the installation of an emergency voice alarm communication system (EVACS). Any fire alarm system may use the sound of the human voice to direct the occupants to evacuate the building totally and completely.

NFPA 72-2022 offers requirements in Chapter 23 and 24 regarding the installation of these systems. You need to pay attention to requirements for both audibility and intelligibility. The model building code or model fire code used by the jurisdiction covering your facility will prescribe an EVACS for those cases where you intend to use partial or selective evacuation. At the present time under the current building codes, the only occupancies that require an EVACS is all new educational occupancies (Use Group E) and high-rise buildings (Special Use).

You will find installation requirements in NFPA 72-2022 to cover such a system in section 23.9, In-Building Fire Emergency Voice/Alarm Communications, as follows:

“23.9.1 In-building fire emergency voice/alarm communications shall meet the requirements of Chapter 24.

“23.9.2 All live voice communications systems shall meet the requirements of Chapter 24.”

NFPA 72- 2022 places increasing importance of the emergency communications systems covered by Chapter 24. In addition, you will find requirements in section 23.10, Prerecorded (Digital) Voice and Tone Fire Alarm Systems, as follows:

“23.10.1 The requirements of Section 23.10 shall apply to both audible (tone and prerecorded voice) and visible notification appliance circuits.

“23.10.2 Fire alarm systems used for partial evacuation and relocation shall be designed and installed such that attack by fire within an evacuation signaling zone shall not impair control and operation of the notification appliances outside the evacuation signaling zone. Performance features provided to ensure survivability shall be described and technical justification provided in the documentation submitted to the authority having jurisdiction with the evaluation required in 23.4.3.1.”

Additional information is found in Annex A:

“A.23.10.2 One or more of the following means might be considered acceptable to provide a level of survivability consistent with the intent of this requirement:

(1)  Installing a fire alarm system in a fully sprinklered building in accordance with NFPA 13, Standard for the Installation of Sprinkler Systems

(2)  Routing notification appliance circuits separately

(3)  Using short-circuit fault-tolerant signaling line circuits for controlling evacuation signals.”

The requirement for notification appliances to operate in those evacuation signaling zones that are not attacked by fire will also necessitate those circuits and equipment common to more than one evacuation signaling zone be designed and installed such that the fire will not disable them. For instance, a signaling line circuit used to control notification appliances in multiple evacuation signaling zones should be properly designed and installed so that one fire would not impair the signaling line circuit, rendering the notification appliances serving more than one evacuation signaling zone inoperative. The power supply requirements of Chapter 10 apply to these systems. The secondary power supply requirements of that chapter meet the intent of these survivability requirements.

“23.10.3 Loudspeakers that transmit prerecorded voice and/or tone signals shall be permitted to be used as fire alarm notification appliances. As you can see, several significant requirements apply to those fire alarm systems installed where an owner intends to employ partial or selective evacuation of occupants.”

Have most areas adopted the Americans with Disabilities Act (ADA) as a part of their requirements?

The Americans with Disabilities Act (ADA) was signed into law in 1990 and amended in 2008, with the amendments taking effect on January 1, 2009.

The ADA protects the civil rights of persons with disabilities. It assures that building owners make reasonable accommodation for accessing the building and its facilities. As civil rights legislation, the ADA provides for enforcement by civil lawsuit brought on behalf of the aggrieved party by the U.S. Department of Justice.

Since adoption of the ADA, several state governments have also adopted legislation to incorporate accessibility requirements. The model building codes include accessibility requirements.

The Americans with Disabilities Act Accessibility Guidelines (ADAAG), most recently published in 2010, serves as the official document that provides guidance in how to apply the requirements of the ADA. This document describes the ADA as follows:

“The Americans with Disabilities Act (ADA) is a landmark law that protects the civil rights of persons with disabilities. It prohibits discrimination based on disability in employment, State and local government services, transportation, public accommodations, commercial facilities, and telecommunications. To ensure access to the built environment, the ADA requires the establishment of design criteria for the construction and alteration of facilities covered by the law. These requirements, which were developed by the Access Board, are known as the ADA Accessibility Guidelines (ADAAG).”

The DOJ also published Bulletin No. 2 in 2003, which it covers visual alarm requirements in detail.

“ADAAG serves as the basis for standards used to enforce the design requirements of the ADA. These standards are maintained by the U.S. Department of Justice (DOJ) and the U.S. Department of Transportation (DOT).

“It is these standards that the public is required to follow. Regulations issued from these agencies provide important information on using and applying the standards.”

Federal law mandates compliance with the ADA and enforces that compliance through the courts. Local authorities don’t have to adopt ADA for it to apply. Because the requirements for fire alarm signaling in ADA essentially harmonize with the requirements in NFPA 72, meeting the ADA requirements simply means installing a system following the requirements contained in NFPA 72-2022.

What types of buildings require fire alarm systems, and what devices are required?

The applicable model building codes and model fire codes adopted by a particular jurisdiction determine whether a building requires a fire alarm system. As mentioned above, the only required occupancies that need EVACS are education and high-rise buildings. These documents also determine which devices and appliances to include in the fire alarm system.

The model codes then require that the building owner install a required fire alarm system in accordance with the requirements of NFPA 72-2022 or whichever edition they reference.

Depending on occupancy and construction type, most buildings require some form of fire alarm system. Even when the building code or fire code does not call for automatic fire detection or manual stations, those codes may require a fire alarm system to monitor the functionality of automatic sprinkler systems, control elevators during a fire, and shut down the heating, ventilating and air conditioning (HVAC) system to prevent the spread of smoke.