As technology enables us to build taller, more sophisticated buildings, it becomes imperative that life safety features keep up with these developments. High-rise buildings offer unique occupancy safety challenges, especially in cases of emergency evacuation, where the existing standard requires buildings over 420 feet to feature a third, emergency-specific stairwell. While conventional standards dictate evacuation via stairs instead of elevators, this can be impractical for buildings over 14 stories, particularly when partial or total evacuations become necessary. Furthermore, it overlooks special accessibility needs for tenants.
Standing 33 stories tall, Gilbane | Shelco’s recently completed 620 South Tryon Street project, also known as the Bank of America Tower, in uptown Charlotte, NC offers an innovative approach to high-rise building safety. The tower is the second project in the country to utilize an occupant evacuation elevator (OEE) to allow efficient egress in emergency situations. This change in code has allowed developers to utilize the existing elevator banks in lieu of a third stairwell, therefore eliminating the need to dedicate rentable square footage to a third stairwell. This revolution is safe should an evacuation be required, and allows landlords to maximize their tenant space.
How it Works:
The OEE is activated when the emergency alarm sounds. At that time, the elevators go into emergency mode and service the floor with the alarm, as well as the two floors above and below its location. This feature makes it more efficient than waiting for an elevator to traverse numerous floors. In the case of multiple OEE elevators in a single bank, elevators that do not serve the alarm floor or two above or below, will return to the first floor in a traditional emergency recall. Within the building fire command center is an upgraded elevator control panel which gives status, location and ability to recall elevators. Because of this, there is significantly more integration required between the fire alarm system and the elevator controls. In place of the traditional single signal for a fire event, the fire alarm system communicates multiple signals per floor to the elevator controls.
Traditional elevators and buildings require emergency power operation, but only in a controlled and limited functionality. With OEE, all elevators that are designated OEE must operate in full under emergency power, including the first responder access elevators.
Since this technology is so new, it requires close coordination and early engagement with inspectors and local authorities having jurisdiction (AHJs) to ensure it meets regional, state and federal code standards. For example, our team at 620 South Tryon Street allowed AHJs ample time to digest the code language within each division and provide written agreements and documentation. Through collaboration and review between the construction team and AHJs, it was found that the OEE system met and exceeded safety standards dictated by the codes.
The Bank of America Tower has not only helped to redefine the Charlotte skyline, but has pushed the boundaries of high-rise safety. The implementation requires additional physical integration and planning, but the results for our client and the tenants alike are well worth it. While we hope no one within the building has to experience the system in action, we can take heart in knowing the best solution has been implemented.
Comments
Andrew Gaskins
Great article and education session Jason!
Thank you for sharing this information.
Raghuvaran Chakkravarthy
Prevention through Design at its best.
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