- Home Improvement
How to Choose Delayed Egress Hardware
Delayed Egress is a function of door hardware that does exactly what its name suggests: it delays people as they try to exit a secured space. If you have experience installing hardware that complies with life safety code you will immediately understand that the very idea of delayed egress is a bit contrary to the whole philosophy of life safety as it applies to allowing folks to escape emergency situations without hindrance by locking systems or hardware. However, people have the right to try to defend themselves against theft of property, both physical and intellectual, and so the compromise of delayed egress was created.
Life Safety code says, in effect, "You can't lock them in, but you can keep them in for fifteen (or so) seconds." Aside from keeping people inside a space while they want to leave, delayed egress systems must otherwise comply with all other life safety code. Therefore all delayed egress systems:
- Warn that egress is delayed through signage
- Upon activation sound an alarm and keep the door locked from both sides for fifteen seconds
- Release the door immediately when the 15 seconds have passed
- Must be automatically unlocked in the event of a fire
- Must otherwise comply with life safety and fire codes
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
Contrary to what some may believe, a delayed egress system is not exempt from compliance with other life safety and fire code. For example, 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 important idea to take away from this is:
If you want to install delayed egress, consult your local AHJ.
That way you won't have to throw anything expensive away later.
The Delayed Egress Process
All delayed egress systems work pretty much identically because they all must comply with strictly enforced life safety code. The sequence of events that comprise delayed egress are more or less as follows:
- When a person attempts to egress, they (hopefully) read the sign and begin to 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 remote annunciators.
Building Blocks of Delayed Egress
A delayed egress system consists of:
- A lock that secures the door from both sides and can be electrically released
- A specially designed, multifunction timer
- A power source
- Switches to turn the system on or off, bypass the system for normal egress, and reset the system after it has gone through the delayed egress process
- An initiation device - a switch that begins the delayed egress process
- A fire alarm system interface
Many delayed egress systems are self-contained, having all these features built right in; it can be valuable to understand each feature, what it does and how it does it.
Locks for Delayed Egress
Locks that meet the criteria of securing the door from both sides are:
- Electromagnetic Locks
- Specially designed delayed egress exit devices
- Asylum or institutional function cylindrical or mortise locks
Cylindrical and mortise locks are rarely used for delayed egress, but it would be possible to do so if you really wanted to, though it would be difficult to make them comply with aspects of life safety code. Electromagnetic locks are the most popular for delayed egress applications because they are so easy to install, however delayed egress exit devices are often the best (or only) solution for some applications.
Delayed Egress Timer
Delayed egress timing modules are specifically designed to be used with delayed egress systems and all delayed egress systems have them. The timing functions the timer performs are:
- Nuisance delay - when someone activates the system, local code usually allows a nuisance delay of up to 3 seconds (where permissible) before the 15-second irrevocable lock release process starts. There may be a sounder that sounds an alarm during the nuisance delay period, giving someone who is trying to get out a chance to change their mind before the system goes into full alarm.
- Exit delay - after the nuisance delay period, the timer causes an alarm to go off for 15 seconds. (Some jurisdictions may allow longer delay periods, but most allow only 15 seconds.) Some systems also offer an electronic verbal countdown to door release during this time. At the end of the 15 seconds the time releases the lock and the person is allowed to exit.
- Automatic reset - in some jurisdictions the timer can rearm the system after a short period of time.
Manual reset, authorized exit system bypass, remote signalling and shutdown in the event of a fire are also functions performed by the timer module through an array of relay contacts.
Typically delayed egress systems in which the lock is an electromagnetic lock are powered by a low voltage, regulated and filtered power supply with battery back up. Delayed egress exit devices are usually powered by a power supply specifically designed to work with a certain exit device. It is advisable to use the power supply that is recommended for the particular exit device.
- On/Off Switch - used only when shutting down the system for service. Note: shutting down the system repeatedly for authorized egress or entry can be harmful to the system.
- Authorized By-pass - used to allow people to exit or enter without triggering the delayed egress system
- Reset - used only to reset the delayed egress system after it has completed the delayed egress process
Key switches, push buttons or access controls such as keypads or card readers can all be used as system switches. The on/off function would be performed by a maintained contact switch whereas all other functions would be accomplished through a momentary contact switch.
The initiation device is a switch that initiates the delayed egress process. Self contained electromagnetic delayed egress locks have the initiation device on board - a switch that detects door motion. The disadvantage to this kind of initiation device is that it can be activated from either side of the door - that is, someone on the outside of the secured space can initiate the delayed egress process by pulling on the door.
Most self contained electromagnetic delayed egress locks feature contacts for an external initiation device. This device can be any kind of momentary contact switch, but the best kind of device is an exit device with an internal request to exit switch inside. This solution best complies with life safety code.
Delayed egress exit devices are basically their own initiation device. When the touch bar is depressed the delayed egress process is initiated.
Fire Alarm Interface
As mandated by code, delayed egress systems must be automatically deactivated by "actuation of the sprinkler system, any heat detector, or up to 2 smoke detectors". Therefore all delayed egress systems are equipped with terminals to be connected to the fire alarm panel via 2 conductor wire. If there is no fire alarm system, technically speaking, one must install one before installing a delayed egress system.
If no fire alarm is present in the building, there are smoke detectors on the market with on-board dry contacts that could do the job of deactivating the delayed egress system. Consult your local AHJ to see if this is a solution she or he will condone .
Self-contained Electromagnetic Delayed Egress Systems
The simplest way to install delayed egress on an opening is to use a self contained delayed egress electromagnetic lock. At right are shown two examples.
On board the magnet is the delayed egress timer and all the requisite electrical connections needed to comply with life safety code.
The initiation device for a self contained delayed egress electromagnetic lock is usually a door motion sensing switch that is integral with the lock. One simply pushes on the door to start the delayed egress process. As mentioned previously, it is also possible with this arrangement to pull the door and initiate the delayed egress process from the wrong side.
To remedy this situation, one can use an external initiation device, such as a regular panic bar with a request to exit switch inside. If access from the outside is needed, one can provide a locking trim on the outside and a switch (key switch or other access control) to bypass the delayed egress system. If an electrified trim is used, the same access control that releases the delayed egress system can release the trim.
Basically the same solution can be used on a fire rated door. Use a fire rated exit device with a request to exit switch in it for an initiation device. Then you can have your fire rating and your delayed egress magnet, too.
If there is a fire rated exit device already on the door, there is probably a retrofit request to exit switch available for it. Therefore on a door that already has a fire rated exit device, a self contained electromagnetic delayed egress system may be the best way to go. Just install a request to exit switch in the bar and install the delayed egress mag lock and you're good to go - as long as your local AHJ approves.
Delayed Egress Exit Devices
A self contained delayed egress exit device is almost as easy to install as a self contained electromagnetic delayed egress lock. Both offer much the same features - which makes a lot of sense given the code governing delayed egress is so specific.
All major exit device manufacturers offer a grade one exit device with delayed egress. The system usually consists of a more or less standard exit device that has an on-board exit delay timer with all the necessary features, an internal, electrically-operated device that keeps it locked, a key switch, a power supply and delayed egress signage. They are all available in panic rated and fire rated versions.
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)
- Cleaner look (no mag lock)
- Does not take up space in the opening
- AHJ may hate mag locks
Yes it's true: there is no fail secure electromagnetic lock. There are mag locks with battery back up, but when the battery runs out the mag will be unlocked while the exit device will still be locked. If the door must provide free egress from one side and remain secured from the other with or without electric power, the exit device is the way to go.
Let's face it, delayed egress mag locks are ugly. Of course, so is delayed egress signage, but you have to have the signage - you do not have to have the mag. Many end users prefer the look of an exit device over a mag. And if you must have an exit device anyway, making it a self contained delayed egress exit device may simply the job while providing a cleaner look.
The American Disabilities Act (ADA) mandates that openings be at least eighty inches tall - that would be six feet, eight inches of clear space to walk through when the door is open. If your door is less than six feet, eleven inches tall it may not be possible to install a delayed egress magnet and comply with ADA. There is at least one delayed egress magnet that is designed to be installed on the pull side and thereby might be a workaround for this situation.
Following the letter of the life safety code, one is not supposed to drill holes through a fire rated door except in a fire rated shop. This alone is reason enough for your local AHJ to throw a piece of hardware off a job, i.e. the mag lock. One way around this is to use a surface mounted bracket to hold the armature of the mag, but if the AHJ just doesn't like mag locks, the best thing to do is to use something else.
Delayed Egress Systems from Components
It is not possible or advisable to install delayed egress on every door. Some doors already do not comply with life safety code and their non-compliance is only made worse by the addition of delayed egress. Yet there are situations where a non-standard opening is approved and later requires a delayed egress system. There are components on the market that can help.
Sometimes, too, 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 of my favorite components for conversion of a door with an existing electromagnetic lock is the Securitron BA-XDT delayed egress system in a box. You get the sounder, the signage, and the timer module in one package. The unit can be easily mounted above the door or high on the wall nearby. 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.
On doors too narrow to accommodate a self contained delayed egress exit device, several companies make delayed egress exit devices with remote timer modules. Some come with an on-board keypad for reset, by-pass and on/off functions while others are prepared to accept a standard mortise cylinder.
Removing the timer module from the device allows the device to be cut shorter, thereby allowing installations on narrower openings.
AHJ On Board
I cannot stress enough how important it is that the Authority Having Jurisdiction be consulted whenever one plans to install a delayed egress system. Before you call the AHJ, take the time to familiarize yourself and understand exactly how a delayed egress system is supposed to work. Make sure your AHJ is on board with your plan, otherwise you may end up with a large and expensive paperweight.
Good luck and happy hardware to you.