As I mentioned in Tuesday’s post, one of the most important requirements for fire doors is that they must be closed when a fire occurs. NFPA 80 and the model codes that are widely used in the US allow fire doors to be held open with automatic-closing devices, which normally hold the door open but release and allow the door to close automatically if there is a fire. These devices are normally hard-wired to receive a signal from the fire alarm system, or battery-operated with an integral smoke detector.
NFPA 80 defines the term “automatic-closing device” as: A device that causes the door or window to close when activated by a fusible link or detector. Although this definition would allow a fusible link which is heat-activated, the International Building Code requires automatic-closing fire doors in most locations to be closed by the actuation of smoke detectors or by loss of power – fusible links would not be acceptable in these locations (more on that here).
There is a hold-open product used in the UK market, that is designed to hold open a fire door until the fire alarm is activated; the SOUND of the fire alarm releases the holder and allows the door to close. I have not commonly seen this technology used in the US (have you?), but maybe it’s a viable option? I didn’t see a specific prohibition in the IBC or NFPA 80, so I asked NFPA staff for their opinion. They agreed that this type of device is neither specifically permitted or prohibited by NFPA 80, and could potentially be approved by the AHJ as an equivalency. Of course, the device would need the proper listings (NFPA 252/UL 10C) for installation as a component of a fire door assembly in the US.
The video below demonstrates how this type of holder works. I’d love your thoughts on this technology.
Note that the fire door requirements in the UK are different from the US requirements, which is why the door shown in the video does not have latching hardware.