A panic bar, also called an exit device, releases the latch when someone pushes the bar while moving toward the door. It is life safety hardware, so it must allow exit without a key, code or card. Access control can secure the outside face only if free egress stays intact.
Panic hardware exists because people panic at doors. The bar works under body weight, in the dark, with no instruction.
How the bar releases
The bar is linked to the latch by a mechanism inside the door or frame. Pressure along the bar retracts the latch and the door swings free. Dogging can hold the latch retracted on doors that may stay unlocked.
Adding access control safely
On a controlled exterior door, the reader may release a strike or maglock while the panic bar keeps the inside free. Alarms and delayed egress must never make the exit depend on power or a credential.
Related:Commercial access controlGlossary: Access control system