An elevator smoke curtain is a thick fiberglass sheet that is installed above elevator doors. When a fire or smoke detector activates, the curtain descends automatically. Then, it acts as a physical barrier to prevent smoke from entering other areas of a building. They're usually installed in elevator shafts since these passageways can act like chimneys to bring smoke to other floors of a multistory building. Smoke curtains also prevent oxygen from traveling through the elevator shaft and fueling the fire itself. They are discreet and blend in with the architectural design until deployed.
It's important to distinguish a smoke curtain from a fire barrier. A smoke curtain will specifically block smoke and push it out of hazardous areas. A drop-down fire curtain, such as a rolling fire-rated door, acts as a physical barrier that prevents the flames from spreading. Smoke curtains are compliant with UL1784 and have a temperature resistance rating of up to 400 degrees Fahrenheit. Fire curtains have fire-resistance ratings of up to 2 hours with temperature resistance up to 1,850 degrees Fahrenheit.
According to the National Fire Protection Association (NFPA), smoke and fume inhalation is the largest threat to human life during structure fires. Smoke contains particles, poisonous vapors and toxic gases that can damage the lungs and other organs. Fires also deprive the air of oxygen, creating more respiratory hazards. This fact makes smoke curtains and other prevention measures like ventilation systems some of the most crucial elements of a fire protection system.
These curtains integrate with a building's existing fire protection system and descend to cover the elevator openings when smoke or fire alarms go off. They provide a complete seal to prevent smoke from traveling up the elevator shaft and entering other building floors, containing the smoke a structure fire produces to a single story and helping to save lives.
Fire curtains also limit airflow to the fire to deprive it of oxygen. Since they prevent oxygen from traveling to the floor of the fire, firefighters can leave doors and windows open without concern that it will fan the flames. By containing smoke to specific areas, smoke curtains help firefighters see which levels and rooms have smoke so they can control the fire. While not fireproof themselves, smoke curtains play a crucial role in containing and shrinking a fire.
When not in use, the curtains are completely hidden in the ceiling. As an alternative to an enclosed elevator lobby, they offer architects increased design flexibility and save considerable space. Building owners also appreciate smoke curtains because they expand the leasable and usable space on elevator-access floors by eliminating enclosed lobby requirements.
Outside of elevator shafts, smoke curtains can also be used over standard openings and doorways throughout a building. A draft curtain is another variation used in warehouses, manufacturing facilities, airplane hangars and other structures with expansive floor plans. Instead of providing a total barricade, they're placed strategically near exhaust vents to encourage smoke to move through the vents rather than throughout the space. Perimeter curtains are used in open shafts like staircases and escalators to create a smoke and fire barrier on all sides.
Many organizations release codes related to fire and smoke protection throughout the building. There are fire curtain requirements for fire-rated doors, alongside codes for sprinklers, alarm systems and other prevention and safety measures. The primary standards for smoke curtains are released by the International Building Code (IBC) and the National Fire Protection Association.
The 2018 International Building Code lists specific requirements for elevator openings and lobbies to prevent smoke from spreading through the shafts. In many circumstances, a building will require an enclosed elevator lobby to act as a smoke barrier. According to IBC 3006.2, Hoistway Opening Protection Required, several conditions necessitate hoistway opening protection for an elevator shaft that connects more than three stories.
First, protection is required if the building does not have an IBC-compliant automated sprinkler system. It's also necessary for a high rise where the shaft is taller than 75 feet when measured from the lowest floor to the highest floor. When the building or a portion of the building is used for an institutional purpose where the occupants are supervised, need physical assistance or are being detained, certain classifications of occupancy also require hoistway protection, including:
These requirements also include three exceptions:
The National Fire Protection Association also includes a variety of standards related to hoistway closures like smoke curtains. For example, NFPA 80, Standard for Fire Doors and Other Opening Protectives, was updated in 2019 and provided new guidance for these devices. Their requirements include:
Cookson Smokeshield™ elevator smoke curtains offer a patented GuideLock™ resealing system and a design that blends in with the surrounding elevator for enhanced aesthetics and security. They comply with IBC 2003-2018 and have approvals for UL1784, ASTME 864 and the ICC-ES-AC77. If you have any questions about smoke curtain requirements for your building or are interested in installing them, please reach out to us online or at 800-294-4358.