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:
- the American National Standards Institute/Builders Hardware Manufacturers Association (ANSI/BHMA) A156.10, Power-operated Pedestrian Doors;
- A156.19, Power Assist and Low Energy Power-operated Swinging Doors;
- A156.27, Manual and Power-operated Revolving Doors; and
- A156.38, Low Energy Power-operated Sliding and Folding Doors.
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.