An exit alarm is an electronic device that activates an alarm when a door is opened. There are several types of exit alarms, including (but not limited to) door alarms, door prop alarms, and door management alarms.
There are many alarms on the market, and knowing your application needs is crucial for deciding which alarm to get.
Hardwired
Advantages
Multiple alarms can be connected together to monitor multiple doors
Battery backup available on most alarms
Other alarm systems, such as a burglar alarm, fire alarm, or carbon monoxide alarm, can be wired into one system
Disadvantages
Harder to install
Higher installation and maintenance costs
Moving equipment and adding on is more complex
Could stop working in the event of a power outage
Battery Powered
Advantages
Easier to install
Lower installation costs
Some battery powered alarms can be mounted directly on the door, saving valuable wall space