When is a Smoke Control System Required?
In our last segment we introduced what a smoke control system is. It’s a system intended to prevent the impact of smoke on occupants within a building.
In this video we’re discussing the triggers for these types of systems. When are they required? Are they provided in cases even when smoke control systems are not required? Let’s dive in.
PROVIDED VS. REQUIRED
Let’s start with when smoke control systems are provided. There’s really two reasons why a smoke control system would be provided.
The first is that they are mandated by code. A specific situation requires a smoke control system in the adopted building code.
The second is that a smoke control system could be provided voluntarily. This could be as part of a code-alternative approach than doing some other, more onerous, type of prescriptive code requirement. This could be an improvement to counteract a code challenge that a building couldn’t otherwise meet. It could bring some additional value to a building owner. But basically, a smoke control system could be used (even when it’s not required by code) as an alternative to help overcome some other shortcoming for a building. We’re going to cover these situations in our next segment.
So in our first case – where as smoke control system is required by code – when is that?
That answer depends on the adopted building code.
In the United States, the International Building Code is the most commonly-adopted model building code. However, other building codes do have similar provisions. The best place to check on whether a smoke control system is required for your structure is to review the requirements in your adopted building code.
In this segment we’re going to work through the various examples of the International Building Code, and later visit some other codes as examples. Keep in mind – even for places that adopt the IBC – there are often local code amendments that will affect our projects. So while these code paths are helpful to get ideas on whether a smoke control system is required for any specific project, we have to do our “code path” and find for ourselves what is applicable in each different jurisdiction.
For the International Building Code, the most prominent and commonly seen smoke control system that is required is for atriums.
Any atrium for in the IBC that is three stories or more would require a smoke control system. These commonly go with an exhaust method, which we’ll cover later.
The requirement for Atriums comes from the IBC Chapter 4. Chapter 4 is the Special Requirements Chapter which addresses unique building types. We work our way from Chapter 4, down to Section 404 for Atriums, and here we’ll see the requirement for a Smoke Control System in Section 404.5. Atriums that connect three or more stories, here, require a smoke control system. And when that system is required, it has to be in accordance with Section 909 of the IBC.
This requirement for Atriums also appears under Section 402 for Malls with Atriums.
We said Atriums are the most common case where a smoke control system is required. Where else would they be?
Still staying in Chapter 4, there are other situations where smoke control systems are required.
The very next section, on Underground Buildings, requires smoke control systems. Underground buildings occur where there is occupancy more than 30-feet (9144 millimeters) below exit discharge, with some exceptions. The concept here is the need for protection against deadly smoke where there is no other option for escape.
WINDOWLESS BUILDINGS (JAILS, PRISONS)
Windowless buildings is another case where smoke control systems are required by the IBC. This shows up under Institutional Group I-3 Occupancies. Section 408.9 talks about “windowless buildings”, where we have non-operable windows that are not readily breakable or don’t have windows at all.
Where might that be? Could be jails, prisons, reformatories, detention centers, correctional facilities.
These are places where the occupants have little or no control over their location, and need to remain safe in place during a fire event.
Smoke control systems help keep those occupants safe even when they have no ability to relocate within or outside a building. Smoke control systems are provided all the time for jails, prisons and the like for this reason. That comes again from Chapter 4.
Still in Chapter 4 but down in Section 410 we have Stages. Now this isn’t a small platform in the elementary cafeteria, this is a true Stage as defined in the building code for theatrical production. These Stages have a few options on protecting the seating area from the stage, and one of those options is a smoke control system. Another is natural ventilation from vents, which tends to be a little more common. These are automatic vents that release upon heat, and are simply sized based on the square footage of area that they cover. Take five percent (5%) of the area of the stage, and that’s the minimum size that vents need to be. That’s detailed in Section 410.
That’s the extent of the situations where smoke control systems are required in Chapter 4 of the IBC. There used to be provisions for smoke control system in healthcare environments, when anesthesia used different gases than hospitals use today. But since the 2012 edition, this has been pulled from the IBC and is no longer applicable.
The IBC also lists smoke control systems as one possible approach for certain situations, but use of a smoke control system is technically “optional” in these cases, because other approaches could also be used. That said, smoke control can overwhelmingly be the most common approach even though technically not code required. Stair Pressurization Systems is one example where we provide a smoke control system even though it’s not required. More on that in our next video.
NFPA 101 has its own set of criteria for smoke control systems.
NFPA 101 has similar requirements for jails and prisons, but it also is more restrictive in healthcare environments. NFPA 101 classifies spaces as an atrium, but requires smoke control when two or more stories are connected, not three like the IBC.
So a space that connects two stories and classifies as an Atrium under NFPA 101 will trigger a smoke control system.
NFPA 101 ADOPTION
This can be an especially important point in the US. Even though the IBC might be adopted for a jurisdiction, NFPA 101 can also be an enforceable code because of the federal requirements for facilities that accept Medicare and Medicaid. CMS, or the Center for Medicare and Medicaid Services, enforces NFPA 101 for their accredited facilities. So even in the US, these healthcare requirements can come into play in regards to smoke control requirements.
NFPA 150: FIRE AND LIFE SAFETY IN ANIMAL HOUSING FACILITIES
Now there are other standards that could trigger smoke control systems as well. One instance is for animal housing facilities. These could be designed under NFPA 150, the Standard for Fire and Life Safety in Animal Housing Facilities. Think of situations where animals are undergoing lab testing; these building types need smoke control to preserve the lives of the animals. This comes from an outside standard, NFPA 150.
NFPA 502, THE STANDARD FOR ROAD TUNNELS, BRIDGES, AND OTHER LIMITED ACCESS HIGHWAYS
Another outside standard that brings in smoke control is NFPA 502, the Standard for Road Tunnels, Bridges, and Other Limited Access Highways. Like underground buildings, tunnels present a unique challenge in that there are limited options for someone engaged in a fire event. There is no direct-access to the outside. Smoke control systems are used here to keep a survivable environment (we use the term “tenable”) long enough for someone to get away from the effects of smoke and fire. That comes from NFPA 502.
In Europe, the concept of performance-based design is much more common than in North America. A performance-based approach is one where important benchmarks are established, the “goal posts”, so to speak, and then there is an engineer-developed solution that must meet those benchmarks. There is not a prescriptive path, by code, requiring a specific approach to get through each step of design. It’s performance-based. A prescriptive requirement, on the other hand, is more narrow or specific in nature. It's providing a solution to meet.
Smoke control systems use this engineered performance-based design approach.
European building codes tend to rely on more performance-based design than North America does. Europe also has an assortment of different adopted building codes depending upon the country and the region where the project is located.
So without getting into each adopted building code, there tends to be more opportunities to meet code using smoke control systems as one possible solution.
So, when is a smoke control system required?
The answer lies in the adopted building code or codes for a project.
Most commonly in North America, smoke control systems are required as the sole-solution for atriums, underground buildings, and windowless buildings like jails and prisons. NFPA 101 holds requirements for smoke control systems in healthcare environments and atriums which are two or more stories. Last, other standards could mandate smoke control systems like NFPA 150 or NFPA 502 for unique challenges like animal housing or tunnels.
In our next segment, we’ll talk about situations when smoke control systems are not required by code, but are still provided and the reasons behind doing so.
I’m Dave Stacy, this is MeyerFire University.
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