January 23, 2020
by Michael Tierney
New technologies can impact everyday life experiences like walking into a grocery store to vacationing at a new family resort. One often overlooked technical connection between these two locations is that both buildings likely use power-operated doors, whether sliding or revolving.
Power-operated doors come in a variety of designs and styles to fulfill the functions of the building envelope and interiors. Among the considerations are reliability, safe egress, accessibility, energy conservation, security, and esthetics. The following four standards cover the breadth of power-operated door products:
This standard covers power-operated doors intended for regular pedestrian use—implying the doors will open automatically when approached by pedestrians and, in some cases, small vehicular traffic. These include swinging, sliding, and folding doors with hardware such as guide rails, knowing act door activation devices (e.g. an automatic door push button), control mats, and sensors.
Power-operated pedestrian doors are commonly specified for accessible routes. As the installation of power-operated pedestrian doors increased, it became apparent this standard was needed to reduce the risk of injury or entrapment because these doors are often installed in areas where heavy foot traffic needs to be accommodated.
A key component of this standard is signage. Signage for power-operated pedestrian doors is required to indicate it is an automatic door, and, depending on the door, dictate direction, caution, and what to do in case of performance failure. These signs include the well-known ‘automatic door,’ ‘slow speed activation,’ and ‘emergency stop’ signs. ANSI/BHMA A156.10 indicates the necessary font, colour, size, and visibility for the various power-operated pedestrian doors.
Another highlight in this standard includes entrapment protection for users to reduce the chance of the automatic door closing on an object. Depending on the door, entrapment protection contains requirements for door opening times, the degree at which a door can open, the force required to prevent a stopped power-operated door if needed, closing speeds, and latch checks. For example, it is noted the time required to open a swing door to 80 degrees shall not be less than one-and-a-half seconds; and the force required to prevent a stopped power-operated swinging door in the last 10 degrees of opening from moving in the direction of opening shall not exceed 133 N (30 lbf) measured 25 mm (1 in.) from the lock edge of the door.
A knowing act references the action of triggering a mechanism for a door operator, such as pressing a switch with the knowledge it will open the door in connection with that switch. As covered in ANSI/BHMA A156.10, once the knowing act device is switched or released, the power-operated pedestrian door shall remain open for a minimum time delay of five seconds. If the knowing act device is located more than 4 m (12 ft) from the centre of the door, the time delay shall have an added second for each additional foot. If a knowing act device is 4.5 m (15 ft) away from the centre of the door, the time delay shall be a minimum of eight seconds.
ANSI/BHMA A156.10 accounts for a cycle test, too, and a salt spray test for 168 hours to ensure the critical parts of the assembly are resistant to corrosion and retain their operability. This standard does not account for a low-energy, power-operated door and does not include fire exits and emergency doors. Additional specifications for this standard include control mat layouts, sensor zones, guide rail details, and further knowing act door activation device installation conditions onsite.
A low-energy, power-operated door is one that opens once a knowing act is activated and signalled, adheres to the maximum amount of kinetic energy allowed by this standard, and is closed by a power mechanism or other means. These doors are intended to improve accessibility.
Unlike the previous standard, ANSI/BHMA A156.19 addresses power-assist/low-energy, power-operated doors, but only for the automatic swinging type. The swing door operators in this standard are assessed for pedestrian, and some small vehicular, use. However, this standard neither regulates doors, finish, or hardware nor doors requiring higher speeds, forces, shorter time delays, and activating sensing devices. Further, each door activation described for power-assist/low-energy, power-operated, swinging doors requires a knowing act. Just as before, the intent of this standard is to prevent injury and entrapment.
Requirements for low-energy, power-operated doors involve an opening speed in which the door will progress from closed to backcheck—or 80 degrees—in three seconds or longer. In this instance, backcheck shall not occur before 60 degrees, and any door opening wider than 90 degrees will continue to open at the same rate as the backcheck speed. These doors shall stay open for five seconds or longer unless push-pull activation is used. In that case, it shall remain open for three seconds or longer.
Requirements for power-assist and low-energy doors are separated in this standard. These requirements primarily consist of signage specifications in the instances of separate switches, the use of remote devices, identifying low-energy doors, and knowing act switch identifiers and when push-pull activation is used to initiate the operation of the door operator.
A primary test for ANSI/BHMA A156.19 determines the durability of the item. A test for durability requires the action of 300,000 cycles with the actual opening and closing time to be within a percentage of the values at the commencement of the test.
Overall, this standard does not attempt to assess any factors that exist with respect to custom design installations.
While this standard concerns manual revolving doors for pedestrian use, the power-operated types (i.e. doors rotating automatically when approached by pedestrians and some small vehicular use) are the primary focus. The included criteria are provisions to reduce the chance of user injury and entrapment.
Covered doors include automatic, revolving doors with a core. These doors contain a large diameter and have about three to four wings attached to a central core. The nominal diameter for the enclosure size is a maximum of 7 m (24 ft). However, two-wing, automatic, revolving doors have a nominal enclosure maximum diameter of 5 m (18 ft).
Other doors in this standard involve access-controlled, revolving doors. The wings on these doors are surrounded by an enclosure with the application for control by a knowing act and trained traffic. However, slow-speed operation and activation alongside wind sensors are inapplicable. Further, these doors are able to act on unauthorized entry as a control mat or sensor is permitted to stop or stop and reverse a door. If reversing, there shall be a delay of two seconds minimum and the reversing speed shall be one half of the standard speed.
The ultimate allowable speed is indicated in the full standard for each type of door depending on the diameter. For example, a 3-m (10-ft) diameter revolving door with a central shaft is limited to 5.7 revolutions per minute at standard speed.
Written examples of signage for power-operated revolving doors include the following:
Additional topics covered in this standard include:
Yet, revolving doors for industrial or trained traffic are not covered, and this standard does not attempt to assess any existing factors with respect to custom installations.
Similar to ANSI/BHMA A156.19, A156.38 predominantly differs in that it covers sliding doors as opposed to swinging types. As with the other standard, this one is for pedestrian and some small vehicular use, and the trigger of all doors described in this standard calls for a knowing act. Further, similar to A156.19, requirements include tests for durability using the 300,000 cycle test and mandates for specific signage specifications dependent on varying factors. Intentions for this standard are based on the desire to promote safety when using low-energy, power-operated sliding doors.
Low-energy, power-operated sliding doors comply with this standard if doors open at a maximum speed of 300 mm (12 in.) per second, close at a maximum speed of 152 mm (6 in.) per second, and remain open for a minimum of five seconds before beginning its closing cycle.
Low-energy, power-operated folding doors shall adhere to a total opening time to 90 degrees in a minimum of four-and-half seconds and will remain open for no less than five seconds before initiating its closing cycle. Unless provided with a finger guard, these doors require a specific clearance. The opening at the hinge side of the folding door can be less than 6 mm (1/4 in.) or a minimum of 19-mm (3/4-in.) wide with the door in any position.
This standard does not assess any existing factors with respect to custom design installations. Doors requiring higher speeds, forces, shorter time delays, and activating sensing devices are not covered in A156.38 and, as appropriate, shall comply with ANSI/BHMA A156.10.
When combined, these four standards encapsulate the safety means and implications for varying power-operated doors. While similar in content topics, the nuances of each standard provide building professionals the means to ensure the function of each of these doors is properly met with testing suitable for its cause.
Michael Tierney has served as the product standards co-ordinator for the Builders Hardware Manufacturers Association (BHMA) for 20 years, where he co-ordinates the development and revision of BHMA’s performance standards. He is a principal member on technical committees for the National Fire Protection Association (NFPA) and the International Code Council (ICC) A117.1 Committee for Accessible and Usable Buildings and Facilities. He also chairs the American National Standards Institute (ANSI) TAG 162 for Doors and Hardware. Tierney can be reached at firstname.lastname@example.org.
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