As their name implies, exit alarms sends notification of an an egress, or exit, via an alarm. There are multiple reasons why building occupants would need to be made aware of an open door:
- Elopement – In healthcare, childcare (schools and nurseries), and senior care facilities, the monitoring of occupants is necessary for their safety.
- Safety – Paths of egress within a building may lead to areas that can pose a danger to occupants that are unfamiliar with the building.
- Security – Propped doors can reduce security to critical areas within a building by allowing unauthorized access.
- Theft Protection and Prevention – Retail environments, especially with exterior doors in areas other than the front entry, are at a constant risk for theft. Warehouses also share this risk.
No matter the reason, exit alarms can protect against and potentially prevent situations with serious consequences.
Exit Alarm Basics
Exit alarms detect egress in two different ways:
- Magnetic Switches – When the switches’ contacts are moved away from each other, such as when a door opens away from its frame, the alarm sounds.
- Dry Contacts – Dry contacts are integrated within the door hardware, such as an exit device. Pressing an exit device’s touchpad completes the circuit and the alarm sounds.
Exit alarms range between 85-105 Db loud. Arming and disarming of is usually controlled by keyed cylinders but keypad options exist as does automatic re-arming. Remote arming is also possible on some models. Exit alarms can be incorporated into existing access control systems by providing alerts and monitoring capabilities. These alerts can then be used to trigger other hardware, such as surveillance cameras.
‘Prop alarms’ are a type of exit alarm that allow temporary egress without an alarm. Prop alarms allow users to set a period of time that a door is allowed to be open, known as an exit delay, before the alarm is activated. Typical exit delays range anywhere from 15 seconds to 4 minutes in duration.
Exit Alarm Types
Exit alarms fall into one of two categories:
- standalone units
- integrated units
Standalone units function as exit alarms only; that is their only purpose. The Detex EAX-500 is an example of a standalone unit.
Integrated units incorporate exit alarms into door hardware, such as exit devices or multi-point locks.
Compared to integrated units, standalone units are usually the more cost-efficient option. They are surface-mounted and generally do not require any modifications to the door or frame beyond the mounting screws for the hardware. Additionally, the existing lock(s) and door hardware are able to remain untouched.
Standalone units fall into one of two categories:
As the name implies, door-mount units are mounted onto the door and are typically powered by 9-volt batteries. The aforementioned Detex EAX-500W is a door-mount unit. Wall-mount units mount to the wall near the door. The Detex EAX-2500 is an example of a wall-mount standalone unit.
Wall-mount units are usually powered by a low voltage transformer and feature a battery backup. Additionally, wall-mount units can be tied into a monitoring or access control system to notify of an egress. I personally prefer wall-mount options when possible for a few reasons:
- Wall-mount units are less likely to snag on something, like a person or clothing, and less likely to be hit by something, such as a cart. Remember, no matter where you place a door-mount unit, it is still in the path of egress and moving individuals/objects.
- Walls usually provide a better mounting surface and some wall-mount units can actually mount onto existing outlet boxes.
Integrated exit alarms are overwhelmingly found in exit devices. The Detex V40 is an example of an integrated unit.
Integrated units can also be found in single and multi-point locks as well as electromagnetic locks (maglocks). Maglocks utilize exit alarms for delayed egress solutions. I will address delayed egress in a separate article at the end of this series due to it’s complexity compared to all other exit alarms.
While integrated exit devices primarily come from the factory equipped with alarms, aftermarket kits are available. Multiple manufacturers offer aftermarket kits that locksmiths can install in the field. The installation of these aftermarket kits typically involves nothing more than a cover plate swap on the exit device.