Integrating Smoke Control During Design Phase of High-Rise Buildings

Very tall buildings have several unique characteristics that increase the severity of potential fire events including higher occupancy, longer evacuation times, access issues for responders and potential water pressure/availability issues. Because of these potential obstacles, integrating adequate smoke control systems during the design process is essential.

“Smoke control” refers to limiting the movement of smoke throughout a building via passive and/or active means. For skyscrapers, a more active approach typically has to be taken but the added square footage of these buildings allows for a large variety of systems to be used.

It is incredibly common for high-rise buildings to have at least one atrium or open lobby. These large volume spaces require a smoke management system when multiple stories are involved. The most common solution is a mechanical exhaust system that actually extracts smoke from the top of the atrium or lobby. This keeps the smoke layer above the occupied areas and allows for the safe evacuation of occupants.

Most building codes also require very tall buildings to provide smoke proof exit stairs for a means of evacuation for occupants, as well as an access point for emergency personnel. In order to comply with the International Building Code (IBC), there are three design options: exterior stair balconies, mechanically ventilated stair vestibules or stair pressurization, with the latter being the most common.

In order to keep the stairwells free of smoke, they are pressurized to a point where, even when a door is opened to access the stairwell, no smoke is able to enter. For this reason, it can require a little more force to open a stairwell door from the interior than if you were opening a regular door in the interior of a building.

The fans and air ducts used to pressurize the stairwell have to be enclosed in non-combustible construction and connected to an emergency power supply. Furthermore, the system must be capable of both automatic activation through smoke and fire detectors as well as manual activation from a control panel.

Controlling smoke in high-rise buildings can be incredibly complicated. If you need help with your high-rise designs, we can help. Click here to sign up for our free high-rise consultation today.