Exit alarms provide a signal when the door upon which they are installed is opened without authorization. The term EXIT can refer to the fact that the device is mounted on an EXIT door, or it may classify the alarm device as one which signals unauthorized egress, as opposed to unauthorized entry. Exit alarms are members of the door alarm family.
Some typical situations where exit alarms are used include:
Hospitals, Custodial & Healthcare: To monitor movements of patients and clients
Retail: To discourage pilferage and the misuse of emergency exits (loss prevention)
Warehouses: To reduce inventory shrinkage
Municipal & Public Buildings/Spaces: To control movement through doors which might lead to dangerous or proprietary areas such as utility rooms, fire escapes or rooftops without having to physically lock the doors, thereby eliminating them as a means of emergency egress.
Schools & Nurseries: To control and monitor children’s movements and keep them within the premises
Hotels & Multiple Occupancies: To mitigate potential dangers from insecure openings, and passback of unauthorized individuals.
Exit alarms can be integrated into door control systems to enforce anti-passback system policies, where it is desired that a door only be used for normal usage in one direction, or when card readers are used for controlling movement through the door from two directions, but obstructing egress would violate building codes, so an audible alarm is used as a deterrent.
The following devices can be considered exit alarms:
• Electronic access control systems with provision for exit alarm annunciation
• Standalone audible exit alarms
• Audible exit alarms with integral locking
• Locking exit devices with audible exit alarms
• Other locking devices with exit alarms and delayed egress
In electronic access control, entry is typically controlled with a card reader or keypad, and egress is usually unrestricted, but such actions are signaled to the control system with a request-to-exit (REX) switch. If the subject door is opened without a valid card read or a REX signal, a forced door alarm results. An electronic access control system can be provisioned with a local annunciator, which identifies the location of the violation and lets the violator know he has been detected.
The usage of the door, the nature of the occupancy and the security issue you are being requested to address will all determine the type of door alarm you will use and how successful a solution it will provide your customer.
When specifying any locking device which is used on an exit, fire door or along the path of egress, the code requirements for that opening and occupancy must be determined, and only approved hardware be used. The standard for exit alarms is covered by ANSI/BHMA A156.29-200.
Be sure that the device you plan to install is appropriate for the environment. For example, in some applications such as hospital wards, a loud audible signal can be disturbing to patients and cause panic and other issues. A battery powered door alarm is perhaps the simplest type of exit alarm. It requires no wiring and mounts on the subject door and frame along with a door sensor.
Some exit alarms can be readily used for the purpose of monitoring a propped or ajar door, for example if a door remains open after an authorized usage such as the door getting stuck or deliberately blocked from reclosing.
Door alarm systems are available which will allow the door to be opened long enough for a typical entry or exit, but once that time envelope has been exceeded and the door is still ajar, an alarm will sound.
Even if the premises has an alarm system, most alarm systems are not connected to every opening in the premises, and more than likely the alarm system is only activated at night. Few premises alarm systems are supplied with audible alarm (local alarm) at an individual door.