How to Choose Delayed Egress Hardware
Delayed Egress delays people as they try to exit a secured space. The idea of delayed egress is contrary to the philosophy of life safety. Delayed egress is a compromise.
Life Safety code says, in effect, "You can't lock them in, but you can keep them in for fifteen (or so) seconds."
All delayed egress systems work in basically the same way because they all must comply with strictly enforced life safety code.
- When a person attempts to egress, they push against the door or other initiation device
- The initiation device signals the timer
- The timer may then time 2-3 seconds wherein nothing happens. This is called a nuisance delay. A nuisance alarm may sound during the nuisance delay.
- The timer sounds the main alarm and begins the irrevocable fifteen-second countdown to door release.
- After fifteen seconds, the door is released
- The system is reset. In some jurisdictions it can reset itself; in others it must be manually reset.
Most systems are also equipped with additional dry contacts that can be used to signal other devices.
Following is an excerpt from NFPA 101A Life Safety Code.
From NFPA Life Safety Code
NFPA 101a lists the following requirements for delayed egress openings:
- doors unlock upon actuation of the sprinkler system, any heat detector, or up to 2 smoke detectors, and
- doors unlock upon loss of power controlling the locking mechanism, and· an irreversible process (such as pushing the door or touch pad) releases the lock within 15 (AHJ can approve a delay of up to 30 seconds) upon application to the release device (15 lbs for not more than 3 seconds), and
- initiation of the release process activates an audible signal in the vicinity of the door, and
- after release, locking shall be by manual means only, and
- signage on egress side of door (PUSH UNTIL ALARM SOUNDS.DOOR CAN BE OPENED IN 15 SECONDS)
Must Otherwise Comply
A fire rated door must remain positively latched in the event of a fire; therefore if the only lock on a fire rated door is a delayed egress electromagnetic lock, this door is in violation. If one adds a UL Listed passage set to comply with the positive latching requirement, this may, according to some Authorities Having Jurisdiction (AHJ) violate the "one motion" and/or "prior knowledge" requirements of life safety code since it would require those exiting in a panic situation to turn the lever and then push the door for fifteen seconds.
The MOST important take away from this is:
If you want to install delayed egress, consult your local AHJ.
Delayed Egress Exit Devices
All major exit device manufacturers offer a grade one exit device with delayed egress.
The advantages of a self-contained delayed egress exit device over a magnet are:
- Exit devices are inherently fail secure (mags are always fail safe)
- Can be fire rated
- Cleaner look (no mag lock)
- Does not take up space in the opening
- AHJ may hate mag locks
Delayed Egress Systems from Components
Sometimes, when retrofitting a delayed egress system to an existing door, one can utilize some or all of the existing hardware by using components to convert the opening to a delayed egress opening.
One component for conversion of a door with an existing electromagnetic lock is the Securitron BA-XDT. It includes the sounder, signage, and timer module in one package. It requires in addition an initiation device, reset, on/off and bypass switches and a regulated and filtered power supply. Several manufacturers make similar products.