Popular Exit Devices And Their Uses
An exit device, also called a panic bar or push bar, is door hardware that unlatches when someone pushes the bar, so people can get out quickly without a key. The common types are rim, mortise and vertical rod devices, and which one fits depends on the door: a single door or a pair, with or without a center post (mullion), and whether it is a fire door. Codes require panic hardware on some doors, not all. Under the 2021 International Building Code, swinging doors serving high-hazard (Group H) occupancies, swinging doors serving rooms or spaces with 50 or more occupants in assembly (Group A) or educational (Group E) occupancies, and doors serving certain electrical equipment rooms may only have panic or fire exit hardware as their latch or lock (IBC 1010.2.9); your local building department decides which code edition applies.
Exit-door rules were reviewed after the Iroquois Theater fire in Chicago on December 30, 1903, which killed more than 600 people; several exit doors were barred and others opened inward and were quickly blocked (Library of Congress). Since then, codes have required exit doors that can restrict entry from outside while allowing easy egress in a fire or other emergency. There are several different types of exit devices in the market and finding one should not be a daunting task. However, not all depict desirable quality and their uses vary from door to door. Here is a brief description of the popular exit devices and their uses:
Legally enforced devices
As mentioned above, codes require exit signs and, on some doors, panic hardware, to reduce risk in an emergency. The type of exit device you choose will depend on your establishment’s size, number of people accessing the building everyday and other minor aspects that dictate the standards to be used. The three main exit devices used in modern buildings include the following;
Mortise lock
A mortise exit device latches with a mortise lock: the latching mechanism sits in a case that fits into a pocket cut into the edge of the door (Von Duprin). Pressing the push bar retracts the latch so the door swings open. Mortise locks are quite easy to use and have been around for a long time.
Vertical rod
A vertical rod exit device latches at the top of the door, and usually at the bottom too, using rods that run up and down the door. The rods can be mounted on the surface of the door or concealed inside it (Von Duprin), and some models leave out the bottom rod (Von Duprin 98/99 Series). Because they do not latch at the edge where two doors meet, vertical rod devices are often used on pairs of doors without a center mullion.
Rim lock
A rim exit device mounts on the surface of the door, with the latch in the device’s center case; the latch engages a strike mounted on the frame when the door closes (Von Duprin). A simple press on the bar releases the latch and the door swings open. On a pair of doors, rim devices need a center mullion to latch against, and the mullion can be removable (Von Duprin auxiliary hardware catalog).
Exit device uses and construction
In order to understand exit devices and their uses, it is first important to note how they work. This is also important when looking for the ideal devices for your building and the proper standard required by the law. Exit devices should feature a latching mechanism and activated door unlatching method that is used to swing the door open in the direction of egress travel in an emergency. Opening the door should be as simple as pressing the activation bar which immediately releases the latch. The building code limits the force needed to unlatch the device to no more than 15 pounds, and the bar must reach across at least half the width of the door (IBC 1010.2.9.3). This ensures anyone inside (even children) can still open the door. Fire doors must be self-closing (or close automatically) and latching (IBC 716.2.6.1), so they shut and latch on their own to hold back fire and smoke. On a fire door, the device must be fire exit hardware, which is panic hardware also listed for use on fire doors (UL 10C and UL 305), and like any exit door it must open from the inside without a key. Exit devices are primarily used to keep the door latched (not locked). This means the door can be opened from the inside at any time with minimal force, and it latches again when it closes.
It is important to keenly review exit devices before spending your money. If possible, consult professional locksmiths who can recommend ideal systems for your building and outlets. Aspects of brand reputation, quality guarantees, use and efficiency are all important to review when looking for exit devices. As a general rule, buy hardware that is listed for the door it will go on (panic hardware, or fire exit hardware on a fire door) from an authorized distributor, and have professionals like Diamondback Lock And Key install them.
Sources
- 2021 International Building Code, Chapter 10 (1010.2 and 1010.2.9) (International Code Council)
- 2021 International Building Code, Chapter 7 (716.2.6.1) (International Code Council)
- Iroquois Theater Fire: Topics in Chronicling America (Library of Congress)
- Von Duprin 101: Exit devices (Von Duprin)
- Von Duprin Auxiliary Hardware and General Information catalog (Von Duprin)
- Von Duprin 98/99 Series cut sheet (Von Duprin)