When a fire breaks out a smoke containment system prevents smoke and heat from moving from area to area. Usually, these systems are a part of an overall smoke control system. The goal is to control the movement of smoke to ensure the objective of having smoke free exit access and contain the smoke to the fire area. Smoke containment systems take the form either of physical barriers such as smoke curtains or as pressure differential systems, also known as pressurization.
When smoke is allowed to spread it might damage other parts of the building far away from the fire, and if spread too far, it will cool down and drop to the ground increasing the risk of the building getting smoke logged. If the smoke is contained, the smoke layer will remain relatively hot and increase the ventilation as hot air moves upwards. This will also provide better visibility in the area for firefighters. Smoke curtains can either be fixed or deployable. Deployable curtains usually are installed at high-level and usually don’t descend to floor level.
The system will deploy when the smoke detector in front of the elevator opening goes into alarm (or on loss of power to the unit). The system is not designed to deploy on general alarm. If an elevator occupant were to encounter a deployed curtain, a screen rewind switch located on both sides of the screen allows for egress. If power is lost, the system operates on a fail-safe basis, triggering screen deployment.
A deployment delay is built into the system to avoid nuisance deploys on brief power outage. As power is restored, the screen will automatically rewind into the housing.
The unit control monitors several system functions including presence of AC power, battery backup condition, system deploy status, and the continuity of all system circuits. The system is a dedicated smoke control device (NFPA 92 A & B) compatible with UUKL controls.
If the curtain senses an object in its path the system will redeploy a er the obstruction is removed.