This video is pretty amazing.  Swallows nesting in a university parking garage could have been locked in when doors were added to convert the garage to the campus bike center.  Is this an example of the swallows’ intelligence, or dumb luck?


Low Energy Auto Operator with Motion DetectorOn a related note (you know I can’t resist), the BHMA standard for low-energy operators (A156.19) requires the operators to be actuated by a knowing act.  A knowing act may be a push plate actuator or non-contact switch mounted on the wall or jamb, the act of manually pushing or pulling a door, or an access control device like a card reader, keypad, or keyswitch (read more about it here).

If a door with a low-energy operator is actuated by a motion sensor, which is not considered a knowing act, it has to meet the requirements of ANSI/BHMA A156.10, which is the standard for full-powered operators.  In most cases this includes safety sensors and guide rails (like the photo at right).

The other disadvantage of using a motion sensor (besides the bird issue), is that the doors are opened automatically each time, creating extra wear-and-tear on the hardware.  The opening speed for low-energy operators is limited so they may open too slowly and stay open too long, another reason to operate the doors manually whenever possible and actuate a knowing act switch when automatic operation is needed.

With that said, in the case of the campus bike center a motion sensor is probably the most convenient way to operate the doors.  They may be missing some guide rails if a current edition of the BHMA standard is in use for their jurisdiction.


You need to login or register to bookmark/favorite this content.