07/08/2002

Electronic Access Control

What’s required in an emergency

 

Voice Intelligibility

Emergency Voice Evacuation Systems also play an important role in the orderly evacuation of buildings during emergencies. And yet, who has not experienced the frustration of not understanding a voice message in a busy airport or train station because of background noise or reverberation? Relief may be on the way. U.S. fire codes are moving toward mandating that the intelligibility of voice messages in new buildings be objectively measured and meet minimum standards. While fire codes have always implied that voice messages should be easily understood by building occupants, only recently has a consensus developed around testing methods that are practical, repeatable, and, most importantly, objective.

Now, using technology originally developed by NATO for improving the intelligibility of military communications, portable intelligibility meters are available that can measure voice intelligibility in both new and existing buildings. Available from SimplexGrinnell, these devices are as easy to use as the dBA meters that have been used for years to measure the loudness of emergency evacuation tones or messages.

Fire! No single word strikes more panic in the heart of a security director. Why? Because national, regional, and local building codes demand that electronic access control systems allow free egress from any building evacuated due to a fire alarm or other life-safety threat. In approving security installations, many local fire authorities interpret this to mean a virtual shutdown of access control, along with the release of all electronic locks.

For a fire marshal, saving lives is paramount, so it makes good sense to remove all obstacles that might hinder the evacuation of a building. For a security director, who balances life-safety with the protection of assets against both internal and external criminal activity, an uncontrolled evacuation is an invitation to plunder. A well-conceived evacuation plan starts with system design and interoperability between fire and access control systems. However, a major issue affecting building evacuation is the fact that access control system release cannot be localized. Fire systems, on the other hand, have evolved to the point where alarm activity can be localized.

Access system requirements are more far reaching. Elevators must be recalled to the designated floor and automatically de-activate. At that point, they can only be operated with a firefighter’s key. Even access-controlled floors must be released to the firefighters. Typically, on all floors, a light in the elevator lobby beside the hall call buttons must indicate that the elevators are in fire mode.

On the alarm floor, as well as above and below it, all electronic locks on egress doors must release. But access systems typically do not distinguish between the doors that must be released and those that need not be affected by a particular alarm. This can leave an entire building insecure. Even if the access system can communicate closely enough with the fire system to be more discretionary, the system integrator has to convince the fire marshal that this is necessary.

In a building with long corridors (or open stairwells), there may be fire/smoke doors located at various intervals. These doors may be kept open during normal conditions, but need to close during an evacuation in order to restrict airflow. The fire system typically engages electro-magnetic door closers – reverse maglocks that hold doors open. If the fire door is access controlled, and normally closed, it must remain latched, but not locked. There are several ways to keep it closed but de-activate the maglocks, but local fire authorities do not always approve of these solutions. Stairwells are also problematic, as most fire marshals demand the ability to re-enter from stairwells at any floor.

Finally, the security director should know the status of every lock and door in the building. The easiest way to accomplish this, of course, is to have a universal release of all doors in the event of an alarm. But it’s also the least effective way of controlling the building in this stressful situation. To achieve effective control, there must be careful consideration by the system designer and consultation with the fire marshal.

Kevin Maynard is director of marketing at SimplexGrinnell (www.simplexgrinnell.com), a leading provider of fire and integrated security systems based in Westminster, MA.

 


Visit our website today to learn about the design flexibility of a Morton building and the endless possibilities of partnering with our designBUILD team.


Wood construction is both cost and energy efficient. Check out Morton Buildings and our designBUILD team online today to discover all the benefits of post-frame construction.


When choosing a metal-clad building for your next construction project, consider Morton Buildings, Inc., and their designBUILD team, we’ll make your dream a reality.

We Can Help You Reduce Energy by 30%

Our mission is to help our customers manage their buildings' energy costs, improve reliability, and enhance performance while having a positive impact on the environment.
CLICK HERE to find out how.

Bluebeam® Revu® simplifies digital facilities document management from design review to leveraging as-builts, maintenance manuals and O&Ms submittals.

 


Visit our website today to learn about the design flexibility of a Morton building and the endless possibilities of partnering with our designBUILD team.


Wood construction is both cost and energy efficient. Check out Morton Buildings and our designBUILD team online today to discover all the benefits of post-frame construction.


When choosing a metal-clad building for your next construction project, consider Morton Buildings, Inc., and their designBUILD team, we’ll make your dream a reality.

We Can Help You Reduce Energy by 30%

Our mission is to help our customers manage their buildings' energy costs, improve reliability, and enhance performance while having a positive impact on the environment.
CLICK HERE to find out how.

Bluebeam® Revu® simplifies digital facilities document management from design review to leveraging as-builts, maintenance manuals and O&Ms submittals.

 


 
comments powered by Disqus

Sponsored Links