There are many dangers behind your typical fire. The most obvious being the fire itself, but just because it’s the most obvious doesn’t necessarily mean it’s the most dangerous. Indeed, in a typical fire, the main cause of death or injury is not the flames themselves. Rather, what poses the biggest danger is in fact the smoke that the fire produces. As such, finding a way to adequately vent smoke during a fire is essential in any effective plan to improve the fire safety of a structure.
In high-rise buildings in particular, the importance of effective smoke ventilation cannot be understated. In such structures, the dangers of smoke inhalation during a fire increase by a fairly significant margin.
The Importance of Smoke Ventilation in Tall Buildings
Because high-rise buildings are, as you’d expect, pretty on the tall side, and it’s an unfortunate fact that heat and smoke both tend to rise. So even at the best of times, an apartment building can be a pretty dangerous place to be during a fire, as the upper storeys may quickly become inaccessible due to the amount of smoke drifting up there from the flames below. Even a small flame can produce quite a lot of smoke, which not only makes it difficult to find escape routes but also causes asphyxiation in its victims. So smoke this quickly becomes the primary danger.
Adding to this are a number of other problems too.
Most floors are only accessible by stairs, especially as lifts will be inoperable during a fire. Such stairways are usually among the first places to fill with smoke during a fire, which can make escape difficult for occupants.
- Main escape routes are also nearly always accessible only through common corridors, doorways and stairwells. These can easily become quite full of people during evacuation, especially on upper floors.
- Smoke can easily spread throughout the building into other areas even if it only one door has been left open during evacuation.
Due to the amount of things that can compromise the fire safety of a building, smoke control systems are an essential part of any building’s design process. In particular the addition of smoke venting can play a crucial role in making the evacuation of a building during a fire much safer and easier to accomplish.
This can be achieved through several things. First, it clears smoke from the corridors and stairways. Not only does this make these areas much easier to find and navigate, but it also greatly reduces the amount of injuries and fatalities relating to smoke inhalation within these areas. It can also assist firefighting activities by creating a smoke-free area for firefighters to operate in, as well as prevent or delay flashover and thus inhibit the development of a fire. Finally, the reduction of smoke through smoke ventilation greatly reduces the amount of overall damage to the structure.
Two Different Breeds of Smoke Venting
The type of building will influence the type of vent used during a fire. Smaller buildings, such as apartment complexes or hotels, will typically employ simpler smoke clearance systems. These simply vent smoke and allow for clearer vision and navigation of a building, however they do not offer much protection to people themselves. While it may be clearer within the building, there’s probably still enough carbon monoxide to cause severe breathing difficulties.
The second form of system is used in much larger complexes, typically malls or large warehouses, where escape routes are both harder to find and also spaced much further apart than in smaller structures. In this case, smoke is actually vented out and away from the building completely, creating more air space for people to breathe in and buying more time to locate and head towards an exit.
It’s mandatory for a building to have at least some kind of smoke venting system in order to facilitate a safe evacuation of a building, and the benefits are immediate. Not only is evacuation smoother and more painless, but a lack of smoke also reduces the amount of panic, which in turn prevents further accident and injury.