One of the more popular American show-business legends is the one about P.T. Barnum and the egress. In 1841, Barnum launched his American Museum at the corner of Broadway and Ann Street in Lower Manhattan. On opening day, folks came in droves to see Tom Thumb, the original Siamese twins, and all manner of curiosities and marvels. But in no time, the museum was filled to capacity, and nobody was leaving, which meant no more tickets could be sold.
According to the story—and banking on his belief that there’s a sucker born every minute—Barnum had two signs painted. He sent one of his roughnecks into the crowded museum with one sign that read “THIS WAY TO THE EGRESS” and instructed him to yell out to the people to follow him.
And they did, expecting to see some exotic beast. Instead, they were led out the back door of the museum into an alleyway, where they saw the second sign that read “EGRESS MEANS EXIT.”
Which brings us to another iconic piece of signage that most of us grew up with: the sign in millions of apartment and office buildings that shows a stick figure running down stairs away from a fire, accompanied by the legend “IN CASE OF FIRE, USE STAIRS, NOT ELEVATORS.”
Well, times change, and egress signs may be adapting.
More than stairs needed
Over the past few years, the regulatory bodies that oversee safety requirements for elevator use in case of emergencies, especially fire, have been revising their thinking and their directives on this subject—a matter of which electrical contractors (ECs) may not be fully aware.
A number of unrelated factors contributed to this radical alteration of century-old conventional wisdom.
The terrorist attack of Sept. 11, 2001, had some wondering if there is a better way to evacuate people. What if the elevators in the World Trade Center had been designed to facilitate building evacuation?
On a less dramatic level, there is the demographic fact of life that our society has an unprecedented historically high percentage of seniors, many of whom (along with numbers of disabled citizens) represent a significant portion of the workforce; their ability to use stairs in case of emergency is limited.
Fortunately, and offsetting these challenges to a large degree, considerable advances in state-of-the-art elevator technology, notably in the area of programmability, now enable a broader choice of options for emergency building egress using the elevator.
There are three organizations involved in the oversight of the emergency exit process, each promulgating its own code:
• The International Code Council (ICC) publishes its International Building Code, which covers the construction aspects of the elevator hoistway or shaft installation.
• The American Society of Mechanical Engineers (ASME) maintains the Elevator Code, which addresses the specifications of the occupant evacuation elevator system itself.
• The National Fire Protection Association (NFPA) issues its Life Safety Code, which covers the occupant evacuation system components other than the elevators, including the hoistway, floor lobbies and adjacent exit-stair enclosure.
Since 2009, all three groups have been updating their codes to produce a workable emergency-evacuation model using elevators to maximum efficiency.
“All the code groups have done their part to create the total package,” said Ron Coté, principal engineer at the NFPA. “Critical to the process was that each of the three participating organizations addressed only its own field of expertise. We held two-to-three-day meetings on a quarterly basis over six years. We all knew that, in the case of an emergency, there have to be more than stairs to get the people out of the building.”
[SB]It was an evolutionary process, building on code modifications of the past, but probably the most innovative new provision was the introduction of the concept of occupant evacuation operation (OEO) in the ASME code.
For some 40 years, a standard requirement in the ASME code was called firefighters’ emergency operation (FEO). In case of fire, and to prevent occupants misusing elevators, the smoke detectors and controls on landings and in elevator machine and control rooms would automatically bring the elevators back to a designated floor location with doors open. The elevators would then be shut down, rendering them temporarily out of service. Firefighters could then see that all elevators were accounted for and use a special key to operate them at their discretion.
But the new OEO process, which incorporates extremely sensitive programmable controls, has fine-tuned that process.
“The OEO system allows elevators to automatically respond to active fire alarm signals at the five active floors,” said David McColl, senior manager of worldwide codes development at Otis Elevator Co. “These are the fire floor and the two floors above and below. This directs the elevators to first service the fire floor, then the two above, then the two below, taking people to either the main floor or a specified discharge level. There is no elevator service to the rest of the building during this time.”
To make all of this operable, the programming system includes virtually instant communications access for occupants both on floor levels and in elevators—a somewhat more sophisticated type of signage than the ubiquitous cartoon of a figure running down the stairs.
“People on unaffected floors can meanwhile be calling for elevators,” Coté said. “So, real-time signage comes up and tells the occupants of the unaffected floors that the elevators are being used exclusively for occupant evacuation on these designated floors, and it tells occupants of the designated floors what the estimated wait time is for the next free elevator, and to either await further instructions or use the stairs at one’s own discretion unless otherwise advised.”
So, yes, you can still use the stairs.
ECs should be aware of three crucial points: First, none of these codified provisions is yet mandatory, and everything depends on what the individual building owner’s evacuation strategy is. Second, there have been very few installations of this kind to date. Third, this is a tight business target virtually confined to new high-rise buildings—not a market that includes retrofit of existing systems in older structures.
So, should you forget about this for now, or is it an opportunity for ECs to get into the emergency egress elevator market on the ground floor?
“None of these evacuation-elevator systems are currently required,” Coté said. “But, if a building owner wants to install one, he has to follow these new code requirements.”
What then, should the EC be looking for generally, and what specifically might be his or her role?
“The IBC says that if a building is over 420 feet, it requires a third stairwell for emergency exit,” McColl said. “But you don’t have to do this if you have occupant evacuation elevators—a high incentive for the builder to provide them initially.
“In terms of specific installations, the code requires emergency power for the elevators, cooling and communications systems, and fire alarm systems including voice announcement capability. People have to be told both with signage and voice alarm what to do and when they can use the elevators.
“The power supply has to be protected for a minimum of two hours either with rated wiring or protection within bulkheads or drywall. All, of this would be the job of the electrical contractor,” McColl said.
This elevator emergency egress codification started years ago, has been refined, and is now in place. However, there are few buildings, if any, with these systems up and running.
As a matter of practicality, owners and architects might consider that it is a lot more cost-effective to build in one of these new systems at the start, because who knows what the requirements might be in the future?
“I don’t know how effectively this subject has been covered in the electrical contracting industry, but we’re all still going through an educational process,” McColl said. “This includes the elevator industry, architects, owners and contractors. It took a while to develop them, but we have little experience in running these new evacuation-elevator systems. We all have a lot of learning to do.”
Stay tuned, and hopefully your opportunities in the elevator egress market will be going up.