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Showing posts with label emergency voice alarm communication. Show all posts

Monday, February 19, 2018

NFPA 72 2016 Chapter 24 Changes

NFPA 72 2016 Chapter 24 - Emergency Communications Systems (ECS)

The following information contains the changes, updates and additions to Protected Premises for Fire Alarm Systems found in Chapter 23 of the NFPA 72 2016 edition. Remember if you see a * make sure to consult the Annex A for additional information.

All information highlighted in this light blue color is NEW to the 2016 edition of NFPA 72.

24.3.1.2* Where no listed loudspeakers exist to achieve the intelligibility requirements of the Code for a notification zone, non-listed loudspeakers shall be permitted to be installed to achieve the intelligibility for that notification zone.

Learn more about voice intelligibility here:

24.3.5.4 Where emergency communications systems utilize Class N pathways that are also shared Level 1 or Level 2 pathways as a means to support ancillary functions, devices, or interconnected systems, the shared pathways shall meet the requirements of 23.6.3
24.3.5.4.1 In addition to the requirements of 23.6.3, a risk analysis shall be performed and approved by the AHJ.

NFPA 72 2016 Chapter 24 - Emergency Communications Systems (ECS) - Pathway Survivability

24.3.13.7 Two-way in-building emergency communications systems shall have a pathway survivability of Level 2 or Level 3.

Exception: Level 1 shall be permitted where the building is less than 2-hour fire-rated construction.

24.3.13.9.1 Area of refuge emergency communications systems shall have a pathway survivability of Level 2 or Level 3.

Exception (1): Level 1 shall be permitted where notification zones are separated by less than 2-hour fire-rated construction.

NFPA 72 2016 Chapter 24 - Emergency Communications Systems (ECS) - In Building Mass Notification Systems

24.5.14* Mounting of LOC Controls

24.5.14.1 Controls that are intended to be accessed by authorized users shall be mounted in accordance with 24.5.14
24.5.14.2 LOC controls, including switches, microphone, latches and so forth shall be located above the finished floor at a minimum of 36" (91 cm) and a maximum of 48" (122 cm) where the horizontal reach is less then 10" (25 cm)
24.5.14.3 If a horizontal reach of 10" (25 cm) to 24" (61 cm) is required, the maximum elevation shall be limited to 42" (107 cm) above the finished floor and the minimum elevation shall be limited to 28" (71 cm).
24.5.14.4 Text and visual indicators, including lamps, screens, displays, instructions, or labels, associated with control or operation shall be visible within all points of elevation between 40" (102 cm) and 60" (152 cm) above the finished floor.
24.5.14.5 Where controls and information are provided in accordance with 24.5.14.2 through 24.5.14.4, provision of additional or redundant controls shall be permitted within the same vicinity at an elevation or reach other than those indicated.
24.5.14.6 Dimensions other than those identified in 24.5.14.2 through 24.5.14.4 shall be permitted when documented within the emergency response plan that ADA guidelines are not applicable or when otherwise required by the AHJ.

Notifier LOC Panel for Mass Notification

24.5.18.8 Addressable primary textual and graphical visible appliances using signaling line circuits shall meet the performance requirements of section 23.6.
24.5.18.9 Non-addressable primary textual and graphical visible appliance circuits shall meet the performance requirements of section 23.7.

NFPA 72 2016 Chapter 24 - Emergency Communications Systems (ECS) - Area of Refuge

24.10.3 The remote area of refuge stations and the central control point shall communicate with each other via pathways based on their performance capabilities under abnormal or fault conditions in accordance with the requirements for Class A, Class B, Class N, or Class X pathways specified in Chapter 12.
24.10.4 All pathways between a remote area of refuge stations and the central control point shall be monitored for integrity.

NFPA 72 2016 Chapter 24 - Emergency Communications Systems (ECS) - Elevator Emergency Communications Systems

24.11 Elevator Emergency Communications Systems. This was in section 24.5.4 of the 2013 edition of NFPA 72
24.11.3 Inspection and testing of elevator emergency communications systems shall be performed in accordance with ANSI/ASME A17.2, Guide for Inspection of Elevators, Escalators and Moving Walks

NFPA 72 2016 Chapter 24 - Emergency Communications Systems (ECS) - Stairway Communications Systems

24.12* Stairway Communications Systems.
24.12.1 Where required by the building code in force and not included as part of another emergency communications system, a stairway communications systems shall be installed in accordance with 24.12.
24.12.2 The stairway communications system shall be permitted to be integrated with another two-way emergency communications system providing it is installed in accordance with 24.12.
24.12.3 The stairway communications system shall comprise remotely located communications points and a central control point
24.12.4 Each remote point shall have the capability to communicate with the central control point. Similar language for Areas of Refuge in Section 24.10.2
24.12.5* Quantity and locations of the remote communications points shall be as required by the building code in force and engineer specifications.
24.12.6* If the central control point is not constantly attended, it shall have a timed automatic communications capability to connect with a constantly attended monitoring location acceptable to the authority having jurisdiction here responsible personnel can initiate the appropriate response. Similar language for Areas of Refuge in Section 24.12.5.
24.12.7 The physical location of the central control point shall be as designated by the building code in fomrce or the authority having jurisdiction. Similar language for Areas of Refuge in Section 24.10.6.
24.12.8 The remote communications points shall provide for two-way communications, provide an audible and visual signal to indicate communication has occured, and indicate to the receiver the location sending the signal. Similar laguage for Areas of Refuge in Section 24.10.7
24.12.9 instructions for the use of the stairway communications system, instructions for summoning assistance via the systems, and written identification, including in braille, of the location shall be posted adjacent to each remote communications point. Similar language for Areas of Refuge in Section 24.10.8.

NFPA 72 2016 Chapter 26 - Supervising Station Alarm Systems

NFPA 72 2016 Chapter 23 - Protected Premises Fire Alarm Systems

Thursday, August 31, 2017

Mixing Speakers and Horns for Fire Alarm

Are we Allowed to Mix Voice Evacuation Speakers with Horns for Fire Alarm Occupant Notification?

This is a question that comes up from time to time and a lot of people have mixed feelings. In a nutshell, the question in a more specific format is as follows: "Am I allowed to install voice evacuation speakers and standard temporal code-3 horns within the same fire alarm system?". To make things fair, we will consult the Standards of NFPA 72 as well as the Code of the International Fire Code Section 907.

What code and standard sections relate to mixing audible signals for fire alarm evacuation?

Here are a list of codes and standards that dance around the topic:

NFPA 72 2016 Sections

10.10.7
18.4.1.1
18.4.2.1

International Fire Code 2015

Section 907 "Fire Alarm and Detection Systems"

NFPA 72 2016 Standard Dissection

NFPA 72 2016 - Section 10.10.7 states "Alarm evacuation signals shall be distinctive in sound from other signals and shall comply with section 18.4.2 and their sound shall NOT be used for any other purpose."

NFPA 72 2016 Section 18.4.2.1 States "Distinctive Evacuation Signal" "To meet the requirements of section 10.10, the alarm audible signal pattern used to notify building occupants of the need to evacuate (leave the building) or relocate (from one area to another) shall be the standard alarm evacuation signal consisting of a three-pulse temporal pattern. The pattern shall be in accordance with figure 18.4.2.1 and shall consist of the following in this order.

ON phase lasting 0.5 seconds +/- 10%
OFF phase lasting 0.5 seconds +/- 10% for 3 successive "on" periods
OFF phase lasting 1.5 seconds +/- 10%

This section in short describes the three-pulse temporal pattern of an audible EVAC signal. This temporal code-3 signal is generated by horns as well as speakers. Remember with voice evacuation speakers, there is still a requirement to have the temporal code 3 whoops between the voice message.

What Does a Distinctive Signal Really Mean?

When the term "distinctive evacuation signal" is used, it's not meant to cover voice evacuation speakers versus horns or bells but to ensure that a temporal 3-pulse pattern or other approved audible tone is used for fire alarm evacuation and ONLY that.

Example: A 4-wire CO detector tied to the building FA system. If the CO detector activates, its internal sounder will alert nearby occupants of dangerous levels of CO via a temporal code-4 audible output. These are typically tied to the FA system via a monitor module and activate a non-latching supervisory signal at the FACU. However for the sake of this post, lets say the CO detector activates speakers in the affected area. These speakers would need to produce the same temporal code-4 sound as it is not a fire alarm signal rather a CO alert tone.

A distinctive evacuation signal in the minds of NFPA 72 is simply put, a temporal code 3 or other approved audible tone. Bottom line is the distinctive signal can ONLY be used for fire alarm evacuation and nothing else.

What about NFPA 72 2016 Section 18.4.1.1?

Another standard section that trips people up on this topic is NFPA 72 2016 - Section 18.4.1.1. The standard states "An average ambient sound level greater than 105 dBA shall require the use of a visible notification appliance(s) in accordance with Section 18.5 where the application is public mode or Section 18.6 where the application is private mode."

Section 18.4.1.1 is not so much for horns and speakers but strobes in areas that have an average ambient sound level of 105 dB or greater. The reasons for this is 15 db over average or 105 + 15 = 120 dB (public mode) or 10 dB over average or 105 + 10 = 115 dB (private mode). This violates the Section 18.4.1.2 which sets a limit not exceed 110 dB for the FA audible appliances.

The language that hits home with this topic is actually found in the Annex. A.18.4.1.1 states "The code does NOT require that all audible notification appliances within a building be of the same type. However a mixture of different types of audible notification appliances within a space in not the desired method. Audible notification appliances that convey similar audible signals are preferred. For example, a space that uses mechanical horns and bells might not be desirable. A space that is provided with mechanical horns and electronic horns with similar audible signal output is preferred."

When is Voice Evacuation Required in Place of Horns?

In order to find out WHEN something is required in the world of Fire Alarm, we have to consult a CODE. Section 907 of the International Fire Code covers "Fire Alarm and Detection Systems". This is the section where all the fire alarm requirements per occupancy group are broken down.

Some examples of voice evacuation requirements are as follows:

IFC Section 907.2.1.1 Group A occupancies with 1000 or more requires voice evacuation
IFC Section 907.2.3 Exception #2 Group E occupancies with more than 100 persons requires voice evacuation
IFC Section 907.2.13 High-Rise Buildings require voice evacuation.
IBC Chapter 3008 Occupant Evacuation Elevators require voice evacuation

The following is a good example of two separate types of fire alarm occupant notification methods being used for one facility. Prior to the newer versions of the International Fire Code, it was typical to have Group E occupancies (schools) with horns in corridors, restrooms, classrooms, etc. However if the auditorium or gym (Group A) has an occupant load of 1000 or more, voice is required. In these cases you would have a standalone voice panel triggered to activate the speakers in the gym/auditorium on general alarm. Currently the 2015 IFC is requiring voice throughout E occupancies if the occupant load is greater than 100 so this is no longer an issue.
To circle back to the original question, "Am I allowed to install voice evacuation speakers and standard temporal code-3 horns within the same fire alarm system?" YES, by code, you are allowed to install different methods of audible tones used for evacuating occupants as long as they have ONE "distinct evacuation signal". Referencing NFPA 72 2016 A.18.4.1.1, it is not desirable to have different types of audible appliances producing conflicting tones. This is based on the different audible appliances being installed in one area where they could both be heard at the same time. For example it would not be desirable to have horns in classrooms and voice evacuation speakers in the common corridor where larger groups of occupants come together. During an evacuation, the classroom doors would be opened to the corridor and the temporal 3 output from the horns would drown out the speakers thus eliminating any sort of intelligibility. Even if you provided the correct digital audio file to mirror the horn's temporal sound output through the speakers, the voice portion of the evacuation message would still be played during standard code 3 cycles on the classroom horns.

Additional VOICE requirements for speakers can be seen in NFPA 72 2016 Section "18.4.1.5".

Saturday, December 31, 2016

Voice Intelligibility for Accurate Occupant Notification

Voice Intelligibility for Clear Evacuation Message

Do you know the reason behind modern fire alarm systems? They are intended to recognize a potential life threatening fire situation such as smoke, flame or heat. It is then their responsibility to alert the masses. If the whole point to a fire alarm system is to alert and inform occupants, then what good does it do if these occupants can not understand the evacuation message? This is what prompted the National Fire Protection Association or NFPA to change the title of NFPA 72 from the National Fire Alarm Code to the National Fire alarm and Signaling Code first seen in the 2010 edition.

Side note: Did you know that NFPA 72 is not a Code reference rather a Standard? Learn more in this article title Fire Alarm Codes vs. Standards.

I am sure seasoned fire alarm system designers have had this pounded into their heads by now but news flash, fire alarm notification signals are no longer the priority in some scenarios. We have always been taught that our occupant notification alert or evacuation messages were to take precedence over any other audio or tone. To an extent this is still correct including outputs such as Musak, Public Address or P.A., Concert or Performance Audio, etc. There are now and have been for some time, fire alarm systems incorporating additional features that make up what is known as Mass Notification. The alert tones, voice messages and canned message instructions of a mass notification system are to take priority over any fire alarm notification output. This was the reason behind the revision and extended title of NFPA 72. The National Fire Protection Association added the word "Signaling" to the title of NFPA 72 as well as chapter 24 covering Emergency Communication Systems (ECS). NFPA 72 does not cover every aspect of Mass Notification system design. If you are seeking additional information on the requirements of these systems, you will need to obtain a copy of the Unified Facilities Criteria (UFC) document titled "Design and O&M: Mass Notification Systems"

If you research the document above, you will become aware that Mass Notification adds a lot of new criteria to the design and engineering of a given fire alarm system, however this article will serve to inform readers on the importance of a term known as Voice Intelligibility. If you consult the Annex D of your 2013 NFPA 72 (starts on page 311) you will find all the information pertaining to voice intelligibility. Below we are going to touch on some of the important factors to keep in mind when up against a mass notification system that must meet specified voice intelligibility measurements.

voice intelligibility can you hear me now

What exactly is voice intelligibility? Voice intelligibility is a measure of how comprehensible speech is in given conditions. Voice Intelligibility is affected by the quality of speech signal, the type and level of background noise, reverberation, and for speech over communication devices, the properties of the communication system. The concept of voice intelligibility is relevant to several fields, including phonetics, human factors, acoustical engineering and audiometry.
In order to meet the criteria of NFPA 72 as well as the UFC, you will need to have what is known as a risk analysis drafted up by a fire protection engineer. A risk analysis is an individual plan for a specific facility. This plan includes a multitude of criteria based on potential risks and threats at the given facility. This risk analysis will breakdown segregated areas of the building and how to evacuate or hold occupants based on individual threatening scenarios. The risk analysis will also explain acoustically distinguishable spaces or ADS. As defined by NFPA 72 2016 D.2.3.1.1 - An acoustically distinguishable space can be an emergency communication system notification zone, or subdivision thereof, that can be enclosed or otherwise physically defined space, or that can be distinguishable from other spaces because of different acoustical, environmental, or use characteristics such as reverberation time and ambient sound pressure level. The ADS might have acoustical design features that are conductive for voice intelligibility, or it might be a space where voice intelligibility could be difficult or impossible to achieve.
Once evacuation or staging areas of the facility are understood, we will need to design the audio potion of the mass notification system. This is where voice intelligibility comes into play. Keep in mind the differences between audibility levels (dB) and Voice Intelligibility. For lack of better terms, one defines the sound pressure and the other defines the clarity and comprehension of the audio. Just because you meet the intent of NFPA 72 chapter 18 in regards to dB levels does not mean you have accomplished an acceptable measurement of voice intelligibility.
How do you measure voice intelligibility? Unlike the use of a dB meter for audibility, voice intelligibility is a little more tricky. There are two scales used to measure intelligibility. One is the CIS scale which stands for Common Intelligibility Scale and the other is STI or Speech Transmission Index. To acquire this reading you will need..... You guessed it, a Voice Intelligibility meter.
What is a passing measurement for voice intelligibility? The voice intelligibility of an emergency communication system is considered acceptable if at least 90 percent of the measurement locations within each ADS have a measured STI of not less than 0.45 (0.65 CIS) and an average STI of not less than 0.50 (0.70 CIS). The measurement shall be taken from an elevation of 5 feet or any other elevation deemed appropriate based on occupancy. In areas of the facility where sound levels exceed 90 dB, it may be impossible to meet these voice intelligibility measurements. In these cases other methods such as LED signage, etc. may be used. For reference the STI scale can be converted to CIS via the following calculation: CIS = 1 + log (STI).

voice intelligibility meter CIS scale and STI scale

There are a ton of factors to take in when designing a mass notification system to meet the voice intelligibility requirements of NFPA 72 and the Unified Facilities Criteria. This article is meant to touch on the main points and get you going in the right direction.

If you are in the market for a dependable voice intelligibility meter, I highly recommend the VOX01 from SDi. This unit is compact, sturdy, very easy to use and comes packed with tons of features and abilities. Here is a direct link to SDi's webpage containing information on the VOX01. Below is a video of me revealing the VOX01 when it first came to market. Feel free to check it out and let us know if you have any questions.

Tuesday, April 22, 2014

Fire Alarm Requirements for Group E Occupancy

Group E: (Education)

Systems required to be monitored per the 2021 IFC section 907.6.6.

A manual fire alarm system (Manual fire alarm boxes) that activates an emergency voice/alarm communication system (speakers, mass notification) shall be installed.

In Group E occupancies with an occupant load of 50 or less persons, a Manual Fire Alarm System is NOT required.
In Group E occupancies with an occupant load of 100 or less persons, an Emergency Voice/Alarm Communication System is NOT required provided the manual fire alarm system activates an approved occupant notification system per section 907.5.

Exception:

Manual fire alarm boxes are not required in Group E occupancies where ALL of the following apply.

The interior corridors of the Group E occupancy are protected by smoke detectors.
Where heat detectors or other approved detection devices are installed in auditoriums, cafeterias gyms or other similar areas.
Shops and laboratories with dust and vapors are protected by heat detectors or other approved detection devices.
Manual activation is provided from a normally occupied location.
The building is equipped throughout within approved automatic sprinkler system installed in accordance with section 903.3.1.1.
The emergency voice/alarm communication system will activate on sprinkler water flow.

2021 IFC section 907.2 - If the facility is provided with an approved automatic sprinkler system in which the Waterflow activates the occupant notification system a minimum of one (1) manual fire alarm box is required to be provided in an area approved by the local AHJ (Authority Having Jurisdiction).

Exceptions:

#1: The manual fire alarm box is not required for fire alarm systems dedicated to elevator recall control and supervisory service.

#2: The manual fire alarm box is not required for group R2 occupies unless required by the fire code official to provide a means for fire watch personnel to initiate an alarm during a sprinkler system impairment event. Where provided, the manual fire alarm box shall not be located in an area that is open to the public.

UL 268 Automatic Smoke Detection Requirements:

System smoke detectors shall be provided for all of the following applications:

Above control panels and power supplies
For the purpose of elevator capture
On all HVAC units over 2,000 CFM (Duct Detector)
For releasing service
Fire Smoke Dampers
Delayed egress locks

Fire Alarm Notification Requirements:

Using a sound pressure meter or dB Meter, verify you comply with the following:

Public Mode Audibility: You must have 15 dB above average ambient sound level or 5 dB above the maximum sound level for at least 60 seconds whichever is greater.