Delayed Egress Defined

Delayed egress is a means of delaying people as they try to exit a space. Delayed egress systems are used in places such as the National Gallery of Art in Washington, DC, where the purpose is to give authorities a chance to apprehend would-be art thieves before they leave the premises, and are widely used in facilities that care for Alzheimers patients across the country, where a delayed egress system helps to keep patients from wandering off while maintaining a margin of safety for egress in legitimate panic situations.

Strictly Regulated

Delayed egress is strictly regulated by national and local building codes, most notably perhaps NFPA 101, egress code of the National Fire Protection Agency. The section of the NFPA 101 that deals with delayed egress is found under ‘Special Locking Arrangements." BOCA (Building Officials and Code Administrators International, Inc) code, another building code that affects delayed egress systems, is also widely used in many states and localities. Different building codes require delayed egress systems to work in different ways. The most important thing to remember about delayed egress and egress code in general is that the final word on any egress hardware is given by the local AHD, that is, Authority Having Jurisdiction: usually the Fire Marshall. When considering a delayed egress system, it is usually a good idea to get the local AHD on board early on.

It is also important to remember that delayed egress system hardware must otherwise comply with regular building codes. For example, a fire rated opening must be equipped with fire rated latching hardware that will remain positively latched in the event of a fire.

Building a System

A delayed egress system consists of:

• Electric locking device, such as an electromagnetic lock or specialized delayed egress electric exit device
• UL listed, code compliant delayed egress timer unit
• Legal signage
• Sounder
• An initiation device, such as a push bar with an internal switch
• An interface with the building fire alarm
• A reset device
• A power supply

How it Works

In general, delayed egress systems work like this:

A person wishing to exit the space activates the initiation device for a "nuisance delay" period of 2-3 seconds*. After the nuisance delay, if the person continues (as instructed by legal signage) to activate the initiation device, an irrevocable 15 or 30-second* process begins during which an alarm sounds, after which the electric locking device releases allowing free egress. Depending on local code, the device may then reset and relock automatically, or may require manual reset and relock at the door. The system is wired to the fire alarm so that when a state of alarm exists the door is unlocked, providing free egress in the event of a fire.

*_{Time periods may vary per local building and fire codes. Also, special arrangements can be made with local AHD.}

Examples

There are two main types of self-contained delayed egress systems on the market today: electro-mechanical exit devices and electromagnetic locks.

Two examples of electro-mechanical delayed egress exit devices are:

• Von Duprin 99 Series Chexit
• Sargent 80 Series Electroguard

Two examples of electomagnetic self-contained delayed egress systems are:

• SDC 1511S
• Schlage Electronics 390DEL