This article provides a brief overview of revolving doors; in particular, how code requirements have evolved, how codes impact design and installation, and how safety and security have become an integral part of revolving door design.
History:
The history of the revolving door dates back to 1888 when the first U.S. patent was granted to Theophilus Van Kannel in Philadelphia, and in 1889 the first wooden revolving door was installed at Rector’s restaurant in Manhattan on Times Square.
Today, thousands of revolving doors are in operation around the world, in virtually every industry and building type with benefits that include aesthetics, energy efficiency, noise dampening, reduction in outdoor pollution, safety, and security.
Code Changes:
In 1942, the Cocoanut Grove nightclub fire in Boston, MA resulted in 492 fatalities. The single revolving door was cited as one of the main reasons for so many casualties. While trying to escape the fire, patrons became trapped in the door while those behind them tried to force their way out. Many died from smoke inhalation only inches from the outside.
As a result of the above fire, many states began adopting laws and regulations requiring improved safety for revolving door installations. Two such requirements from that time, and still required today, is the adjacent swing door and bookfolding of door wings. Interestingly enough, these are not requirements in other parts of the world.
In 2015, IBC added language requiring revolving doors to comply with ANSI/BHMA A156.27 Power and Manual Operated Revolving Doors. In 2018, NFPA 101 added similar language to their code, and now both codes have almost identical requirements for revolving door installations.
One notable exception between the two codes, is that NFPA 101 gives doors larger than 9 ft. in diameter the full unobstructed passage width (when bookfolded) for exit capacity calculations. IBC still only allows 50 occupants maximum regardless of the door diameter. For doors 9 ft. diameter or larger, the passage width is greater than 3 ft. A 3 ft. exit width would accommodate 180 occupants. It is likely that the requirements in NFPA are relaxed for these larger doors given their wider passage width, in addition to improvements in technology, safety and fire safety record over the years.
Revolving Door Requirements:
Here are some of the more notable requirements that often lead to confusion with the design, installation, and enforcement of revolving doors:
Revolving doors must be at least 10 ft. away from a stairway or escalator and have a dispersal area between the two so that people are not stranded in an unsafe place should the door get backed up as people enter or exit.
Each revolving door shall have a side-hinged swinging door in the same wall and within 10 feet of the revolving door. The adjacent swing door requirement dates back to 1942 and is intended to be the primary exit -- with egress capacity calculations determined by the occupant load that is using that exit. Other door types could provide the primary exit, for example, sliding doors, just so long as the door(s) meets the provisions of the code and the exit capacity calculations serve the occupant load using the exit(s).
Each revolving door is given credit for only 50 occupants, regardless of the passage width in bookfold position. As previously noted, NFPA 101 has an exception for doors over 9’ where the actual passage width in bookfold position is used for exit capacity calculations. As noted in the adjacent diagram, the two swing doors and two revolving doors would serve an occupant load of 460 persons. For new construction, exits are typically designed to serve well in excess of the occupant load; however, when change in use and/or substantial renovations are made that impact the means of egress, new exit calculations are required.
Each revolving door shall be capable of breakout for egress in accordance with ANSI/BHMA A125.27 and shall provide an aggregate width of not less than 36 in. In the diagram to the right, the B + B dimension must be ≥ 36".
Both IBC and NFPA 101 limit the breakout force (collapsing force) to:
• ≤ 130 lbf if a component of a means of egress
• ≤ 180 lbf if not a component of a means of egress
• ≥ 180 lbf if the breakout force is reduce to ≤ 130 when not less than one of the following conditions are met:
- On power failure or power to door wings.
- Actuation of automatic sprinkler system.
- Activation of smoke detection system (w/in 75’).
- Activation of a manual control switch.
Access Controlled Revolving Doors (Security Revolving Doors):
The scope of ANSI/BHMA A156.27 applies to automatic (power operated) revolving doors and manual revolving doors. Access Controlled Revolving Doors, often referred to as Security Revolving Doors in industry circles, are not in the scope of ANSI/BHMA 156.27; however, language does exist in the standard for their design and installation, and owners are encouraged to comply with the appropriate safety provisions included therein. Security Revolving Doors are intended for trained traffic where the primary application is access control with anti-tailgating and piggy-backing technologies an integral part of the design.
Manual Revolving Doors with Security:
Unlike access controlled revolving doors (security revolving doors) that are intended for trained traffic and used to prevent tailgating incidents, the use of integrated security with manual revolving doors is becoming more commonplace. New technologies make them easier to operate, accept larger diameters (up to 10 ft.), and include security features. These features include power assist (allows for larger diameter doors), electronic shaft locking (at door or remotely), integrated access control, positioning (quarter pointing), and bullet resistant glass.
Security Portals (Mantraps):
Security portals (mantraps) are not referenced in either IBC or NFPA 101, which often leads to misinterpretations in design, installation, and enforcement. They may be treated as Security Access Turnstiles, Revolving Doors or Vestibules with little or no consistency among the three. This topic will be part of a future blog, as it is a technology that is in widespread use for high security applications and should be given visibility in the codes and standards.
Future blog posts will include other security entry technologies, with discussion about technology, applications, codes, compliance standards, and other areas of interest.
Dale Gigandet, PE, CPP, CISSP
Security Entry Consultants, LLC
978-971-6818