Burned!: 3 Fire Safety Myths About Building Equipment Reliability
Travis Hannah
Life Safety Circuits are <10% of the EC package, yet do >95% of the heavy lifting in an Emergency! Downtime is not an option.
Designing fire safety in a commercial building requires coordinating the design & construction of a range of various systems. These systems include suppression, fire alarm, communications, smoke control systems, structural protection, passive fire network, and human egress systems to start. It is the Fire Protection Engineer’s (FPE) job (sometimes Civil Engineer) to bring together the design of these systems based on the unique building characteristics of the project, occupant characteristics, and possible fire scenarios so these systems network as one unified fire safety system.
Fire Safety Myth (1): All Sprinklers Will Join the Party
Yes, their history is one of being highly effective and reliable, however fire sprinkler systems are often misunderstood and undervalued by many, even professionals. This is particularly of concern in buildings that house sensitive materials, like museums, libraries, telecom facilities, and computer labs, where the fear of water damages may eclipse the benefits of active fire protection. One BIG misconception about sprinklers is that every sprinkler in a building will activate once a fire is detected, but this is not true. Individual sprinklers will only spray when the temperature at the location of the fire reaches a predetermined turn on temperature. So, during a fire, only the sprinklers in the immediate location of the fire will discharge. A study on fire incidents in buildings with sprinkler protection found that only one sprinkler was activated in 77% [1] of cases where sprinklers were used. It is therefore essential that owners, Engineers, General’s and Trade teams in a building understand how fire sprinklers operate to ensure the best possible fire protection outcome, and the successful implementation of an inspection, testing, and maintenance program.
[1] Ahrens, Marty, "US Experience with Sprinklers," National Fire Protection Association, Quincy, Massachusetts, 2021.
Fire Safety Myth (2): Equipment Assemblies Keep Their Cool for Two Hours Straight?
Structural fire protection is a must so that the building's structure remains intact and secure when exposed to the energy of the fire. Structural units like floors, roofs, beams, and columns are covered with rated insulation, or other forms of protection, to prevent them from failing during the high temperatures of a fire. Ensuring that the occupants can safely egress, and firefighters can extinguish the fire. National building codes (IBC, NFPA5000, NBCC) and local codes, typically identify the level of protection, based on a guideline level of fire resistance standard from a Nationally Recognized Testing Lab (NRTL). (Examples – UL, FM, ETL, CSA)
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What most people forget, or don’t understand is that the standard fire test(s) do not account for all possible fire scenarios. The tests provide a uniform basis for determining fire resistance under lab conditions but does not necessarily represent every type of fire that could present itself in a building. Determining factors such as fuel, ventilation, finish material properties, and room layout can impact fire strength and are not included in the basic standard test(s).
Basic structural fire protection test(s) may be suitable for most construction, they may not be sufficient for modern complex facilities such as tall offices, or patient towers, or those of unique construction features. For complex construction a performance-based scenario to structural fire protection is more effective. This addresses the unique features of the building and is not limited to a standard fire test. It involves determining the temperature exposure to a building resulting from a fire, the temperature timeline within the structure or section, and the structure’s response. Looking at these considerations, then ?stakeholders can engineer a fire protection system that is focused to the specific needs of the project building.
Fire Safety Myth (3): Mass Timber and Wood In General Is A Fire Hazard
?Mass Timber construction of Tall Buildings, where the structural components are made of engineered wood as a result of new understandings in engineered timber products, and determined economic benefits of prefabricated timber sections. In addition, the sustainable and environmentally friendly review of wood, has made timber buildings very attractive to building owners and communities. Mass Timber uses sustainable resources, consume less energy during the manufacturing process, and allows for the woods reuse after the building has served it use, making them more environmentally friendly than other steel and concrete systems. More Mass Timber buildings are being constructed globally.
There is a misunderstanding in the public, where Mass Timber or Engineered Wood building are considered unsafe when exposed to fire conditions, in relation to combustibility and structural stability, creating hesitation with some design professionals, government regulators, and fire professionals to view tall Mass Timber buildings skeptically. When Mass Timber construction is exposed to fire, the outer layer burns and turns to char, creating a protective layer that acts as insulation, like a green patina is generated during oxidation, on unprotected copper, slowing the heating time cycle to the un-exposed side and allowing the timber assembly to maintain its structural integrity for extended time. The pressures of sustainability by the public will demand that Mass Timber buildings become an greater and greater integral part of the construction landscape.
The entire concept and design team should understand the pros and cons of Mass Timber buildings. Fire Safety organizations continue research on construction methods related to engineered wood, which advance public and professional knowledge on wood products and progress construction techniques when designing with it.