October 18, 2011
Voice Communications Support Fire Alarm
By Barb Carss
Emergency alarms effectively catch listeners’ attention, but convey little else about the risk they may face and how they should respond. New measures in the 2010 National Building Code are meant to provide clearer instructions to people potentially or actually evacuating a large building.
Voice communication systems are already required in high-rise towers, where stairwells typically cannot accommodate the entire occupancy at once and spoken directions are needed to guide a sequential emptying of the building. The 2010 National Building Code now extends the requirement to a wider range of building types and sets a new standard for the intelligibility of the message.
NEW STANDARD TO GUIDE COMMISSIONING
A new CAN/ULC standard sets out steps for testing fire protection and life safety systems to confirm that all components of an integrated system perform as designed.
This includes guidelines for new installations or modifications covering 20 different emergency response systems that could be triggered to function in tandem with others, recommendations for retro-commissioning existing systems that did not undergo integrated testing when initially installed, and recommendations for periodic re-testing.
The draft version of CAN/ULC-S1001, Integrated Systems Testing of Fire Protection and Life Safety Systems, was released for public comment in July 2011 and is expected to be formally approved later this year. It will be referenced in the next cycle of the National Building Code and National Fire Code in 2015. In the interim, provincial codes that adopt the requirement for commissioning could reference CAN/ULC-S1001 once it is finalized.
“It gives a process for complying with a requirement that is quite misunderstood,” says Simon Crosby, Chair of the ULC sub-committee that helped develop the standard and Project Manager with the life safety and code engineering firm, Randal Brown & Associates Ltd. “What the owners call commissioning and what the code writers understand commissioning to be are sometimes two different things.”
Often, components of a life safety system have been tested in isolation or tests have simply verified that relays are in place to communicate with other system components, but have not tested if those components respond as intended.
“The code intent is to make sure, for example, that the fire alarm system is actually talking to the fire pump,” Crosby notes. “Verifications are fine, but sometimes they miss things. I’ve never seen a building that is 100% perfect.”
If these measures are adopted into provincial building codes, all new high-rise towers and buildings designed to accommodate 1,000 or more occupants would require voice communication systems that can broadcast messages that meet a sound engineering benchmark of 0.70 on the Common Intelligibility Scale (CIS). It’s expected that local building officials would assess requirements on a case-by-case basis for expansion and major renovation projects.
“With expansions, obviously the new space would have to meet the Code, but depending on how it’s intertwined with the existing system, the AHJ (authority having jurisdiction) might require a revamp of the whole system,” says Philip Rizcallah, Senior Technical Advisor with the Canadian Codes Centre at the National Research Council. “For renovations, it’s complicated because this could be a very expensive fix. It may require three, four or five times more speakers. A large boardroom or conference centre might have 15 speakers currently and the new requirement might necessitate 50.”
Both the 2010 National Building Code and the 2010 National Fire Code, which applies to existing buildings, now mandate commissioning when integrated life safety or fire protection systems are installed or modified and this, too, would come into play for expansion and renovation projects. This new requirement is meant to ensure that all components of the system perform in the intended interrelated way. (See sidebar)
ROOM FOR INSTRUCTION
The rationale for voice communication systems differs somewhat in so-called assembly occupancies since they’re more often low-rise buildings with numerous perimeter exits that aren’t as vulnerable to crowding as a high-rise stairwell. However, the occupants are less likely to be in the facility routinely and fewer of them will be familiar with its layout.
“These are occupancies where there are a lot of people, and a lot of people who don’t necessarily know where the emergency exits are. If it’s something like an arena or a concert hall, they’ve also often paid a lot of money for their tickets and are reluctant to leave until they know exactly what’s happening,” observes Fred Leber, Chief Executive Officer with LRI Fire Protection and Building Code Engineers.
The late Dr. Guylène Proulx, a senior researcher with the National Research Council’s Fire Research Program, was one of the preeminent scholars on this aspect of behavioural psychology. Prior to her death in 2009, she led numerous studies and published several papers exploring human response to fire alarms and voice communications, and the importance of social interaction and information exchange in evacuation procedures.
Saskatchewan is one of the first provinces to adopt the 2010 National Code (along with Manitoba and Nova Scotia) so developers there are still sorting through some of the details that came into force on September 1, 2011. Building permits issued before that date will not be subject to the new requirements even if construction is not yet complete.
Some of the building types now compelled to have voice communication systems – such as schools and hospitals – were already customarily built with public address systems. Other assembly occupancies newly mandated to have voice communication systems include shopping malls, auditoriums, banquet facilities, arenas and large recreation complexes. However, many of the stand-alone buildings in retail power centres will remain exempt.
“The criteria of 1,000 people [occupancy load] really excludes most of the retail properties we develop,” notes Blair Forster, Vice President, Development, with Saskatchewan-based Harvard Developments Inc., which currently has three retail projects in progress in Regina and Saskatoon. “Maybe something like a new Walmart that has 1,000 parking spaces would be the type of development that would trigger the requirement.”
Nevertheless, he endorses the concept.
“In any building with a two-stage fire alarm, it’s nice to have the voice communication capability to advise people to either standby to evacuate, or to actually begin to evacuate. Voice communication is far more effective than a series of beeps,” Forster maintains.
For developers and their consultants, achieving the mandated intelligibility standard is the bigger concern.
Previously, the Code called for “acceptable intelligibility” with no definition of what was deemed acceptable. The new standard eliminates that vagueness, but building owners/developers are likely to become more dependent on specialized consultants to assess the acoustical conditions, determine how many speakers will be needed, and test and verify the system’s performance.
Intelligibility differs from audibility, and is a measure of humans’ comprehension of an electronically transmitted voice message. The Code’s requirement for messages to meet an equivalent score of 0.70 on the Common Intelligibility Scale is in sync with the standard for mass notification systems in NFPA 72, National Fire Alarm and Signaling Code, which is commonly referenced in U.S. codes and building by-laws.
Informed industry observers suggest that voice communication systems in most existing buildings do not achieve this intelligibility score. New buildings will likely have a significantly greater number of speakers installed.
“It is not fully understood how to comply with this,” says Simon Crosby, a Project Manager with the life safety and code engineering firm, Randal Brown & Associates Ltd. “Generally, with voice communications, more speakers at a lower [volume] setting are better than fewer speakers with high settings.”
The Code allows for live or pre-recorded messages, which can be delivered in normal voice or synthesized tone. Building owners/managers could rely solely on live messages if they have 24-hour staffing on-site, but many life safety experts consider pre-recorded messages – which can be recorded in a calm studio environment and narrated by professional elocutionists – a more consistently reliable option.
The Code does not specify the language of communication, but since it now applies for all new federal buildings, voice communications in those buildings will be in both English and French, likely broadcast first in the predominantly spoken language of the locale, followed by a message in the other language. In other adopting jurisdictions, Rizcallah speculates that practicality and the predominant mother tongue will similarly dictate the choice of language.
“If it’s in Alberta, the message would probably be in English. If it’s in Quebec, it would probably be in French,” he says.
Nor does the Code specify how frequently a message should be broadcast. Rather, those details are typically contained in a building’s fire safety plan – a legislated requirement in most provinces for most commercial, industrial, institutional and multi-residential buildings, which must be approved by local fire prevention authorities. Again, life safety experts suggest pre-recorded messages can enhance diligence.
“You can have pre-recorded messages for the planned or common incidents such as fire drills, notice to stay in place and prepare to evacuate, or instructions to evacuate. Let’s say it’s a hotel with a lot guests who are Mandarin speakers. You could have pre-recorded messages in both English and Mandarin,” Crosby explains. “Of course, in any scenario, you would also always have the flexibility of adding messages in live voice.”
Code adoption is something of a haphazardly harmonious exercise across Canada. Six provinces and three territories adopt the National Building Code, albeit on their own schedules and with some amendments. Quebec, Ontario, Alberta and British Columbia produce their own building codes, but code drafters in those four provinces try to keep their regulations in sync with the national model as much as possible.
Rizcallah predicts that most provinces will ultimately be on board with the new requirements for voice communications. “We’re not hearing any rumblings that they are not going to adopt this,” he reports.