Consulting-Specifying Engineer - January 2008 - (Page 36) Now, it’s your turn to Talk Back! being impeded by occupants egressing.” Under some scenarios, Galioto explained, the other elevators can be used for evacuation. The other three are 6,000-lb. elevator cars, and can be used for an evacuation supervised by emergency responders. “If firefighters found a large group of people who were injured or disabled, they could bring them down in the 6,000-lb. cars,” Galioto said. Designers separated the service vestibule from the office space by a series of doors that provide smoke separation. The elevator service lobby will be pressurized and use water-resistant equipment. “It is not intended for building occupants to use those elevators to exit the building,” Galioto said. “The standard approach still exists that building occupants evacuate a floor of the building using stairs. We don’t want to reeducate the public for this building.” This touches on a point that is being explored by the code-making bodies and a major paradigm shift regarding elevator use for evacuation of occupants. Building occu- pants have traditionally been instructed not to use elevators in fire and similar emergencies. “Use of elevators [for evacuation] has been studied for a number of years,” said Doug Evans, PE, fire protection engineer with Clark County, Nev. “We are moving more and more in that direction. Those who understand agree that elevators can provide a benefit for evacuating tall buildings. It hasn’t gotten in the codes yet.” “For tall buildings, people are thinking of using elevators now more than they did in the past,” said Jeffrey Tubbs, PE, associate principal with Arup Fire’s Boston office. “It can be pretty arduous to walk down 100 or more stories of a building, so that’s a pretty compelling argument to use elevator evacuation.” Tubbs suggests two different ways that people are looking at the use of elevators. One is using elevators to take occupants directly off the floor. The other is for occupants to walk down a number of floors and use the elevators from there. “It TalkBack, an exciting, new feature on csemag.com, lets you interact and voice your opinions about the latest news affecting building projects. Communication and notification Efficient notification systems have been used for tall buildings for quite some time. “In a high-rise building, the codes typically require voice communication with general and selective paging on each floor. This allows broadcasting live voice messages selectively to floors or throughout the building,” said Jeffrey Tubbs, PE, associate principal with Arup Fire’s Boston office. “In terms of notification for tall buildings, this capability has been included in high-rise design since the 1970s.” But while the communication systems for building occupants hasn’t changed much, the technologies to aid emergency responders has. “It is essential for emergency responders to have information,” said Carl Galioto, FAIA, technical architecture partner, Skidmore, Owings & Merrill LLP, New York. “Having cameras in stairways and key vestibules is very important so that from the security center or fire command center the person who is in command of emergency response operations can see what’s actually going on in all these particular spaces. In 7 World Trade Center (WTC) we have numerous cameras in the stairs and various vestibules. One WTC will have cameras at all the service lobbies and stairs, so it will give more information to firefighters. There also is some new technology with regard to communication for emergency responders using coaxial cable so that their wireless communications systems function.” “What we did in the last cycle in the 2007 edition of NFPA 72, National Fire Alarm Code, was to add an annex on mass notification to provide guidance for design and implementation of mass notification systems,” said Raymond Grill, PE, principal at Arup and the leader of Arup Fire in the Americas. “We also modified the body of the code to allow fire alarm emergency communication systems also to be used as mass notification systems so that they could actually serve dual purposes.” Read what other readers like you think about vital issues. TalkBack is available on every Consulting-Specifying Engineer article and blog. The first destination for consulting engineers www.csemag.com 36 Consulting-Specifying Engineer • JANUARY 2008 http://www.csemag.com http://www.csemag.com
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