Smoke control systems are an important life safety feature in a building. Although there are many types of smoke control systems, they generally share one or more of the following objectives: (1) limit the spread of the products of combustion; (2) maintain tenable conditions for egressing occupants; (3) remove smoke from area(s) of incident; and (4) allow for safer conditions for first responders. To be effective in achieving these, the systems must be capable of operating in adverse conditions experienced during a fire event.
The International Building Code, Section 909, mandates many design features intended to improve the robustness of smoke control systems, allowing them to operate consistently and for the appropriate duration. A summary of the major smoke control protection requirements is outlined below.
- Equipment (ducts, fans, dampers, etc.) must be suitable for its intended use and probable exposure temperatures.
- Ducts must be leak tested to 1.5 times the maximum design pressure and supported directly from fire-resistance rated structural elements of the building by substantial, noncombustible supports.
- Automatic dampers must be listed and conform to the requirements of approved, recognized standards.
- Fans must be provided with an increased duty rating and extra belts.
- Systems must be provided with legally required standby power. The standby power source and its transfer switches must be in a room separate from the normal power transformers and switch gears and ventilated directly to and from the exterior. The room is minimally required to be enclosed in 1-hour fire rated construction.
- Elements of systems relying on volatile memory (i.e. Building Management Systems) must be supplied by uninterruptable power sources that span 12-minute primary power interruption. Elements of systems susceptible to power surges must be suitably protected by conditioners, suppressors, or other approved means.
- Controlling equipment (Fire alarm and/or Building Management System) must be UL listed for smoke control use complying with UL 864.
- Smoke control wiring must be enclosed within continuous raceways.
- In addition to the above, there are fire rated separation requirements specific to stair and elevator pressurization systems. Certain design objectives of other types of smoke control systems may employ similar strategies.
It is critical that smoke control systems are both reliable and durable in order to achieve their intended performance objectives. Code Red as a wealth of knowledge and experience in consulting on, designing, modeling, inspecting, and testing smoke control systems. Please reach out to us if you have any questions or would like assistance with your existing or new smoke control system.