Tho Baltimore Symposium NFPA Panel Session in New Orleans
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is report offers an overview of the surization, as well as the appropriateness titled “The Use of Elevators in High-Rise ongoing efforts of the the elevator of sprinkler waterflow versus smoke de- Buildings During Fire Emergencies” was rindustry, the NFPA, the National In- tector initiation of elevator recall. It also held at the NFPA Annual Meeting in New stitute for Standards and Technology provided an opportunity to publicize a Orleans in May 1992. (NIST), the American Society of Mechan- number of elevator operation problems Session panelists pointed out that the ical Engineers (ASME), and other in- that were known only to the elevator NFPA Life Safety Code Subcommittee on volved parties to develop solutions to the industry, such as low heat tolerance of Means of Egress had recognized this ba- problems involved in enhancing the secu- microprocessor controls and water sen- sic problem nearly 15 years ago, culmi- rity of elevator systems against various sitivity of door interlock and other eleva- nating in the Section 5-12 proposal that aspects of the fire environment. Their tor equipment in hoistways. was passed by the Safety to Life Commit- goal is the continued use of elevators The 200 attendees, who were elevator tee, but was rejected on the floor at an during fire emergencies. and building officials and fire profession- annual meeting more than a decade ago. als, left the meeting determined that At the time, the prediction was made that Tho Baltimore symposium some immediate code revisions and fur- if the NFPA membership failed to act In February 1991, the NFPA, the ASME, ther study of local fire service experience favorably on the proposal, the federal and the Council of American Building were steps to be taken as soon as possi- government would force the issue. Officials (CABO) sponsored a symposium ble. A few of these actions are outlined Some European and Asian nations also on elevators and fire in Baltimore, Mary- below. have recognized the problem, and several land. It was organized in anticipation of are ahead of the United States in the the forthcoming Americans with Disabil- NFPA panel session process of solving it. Currently, we are ities Act and its associated Accessibility in New Orleans enmeshed in a lack of building code Guidelines (ADAAG). To broaden the fire community’s aware- coordination and a federal law to be The symposium emphasized a number ness of this major exit problem and to enforced by individuals who are long on of well-known questions regarding the report on progress made since the Balti- legal training, but may be unfamiliar with need for elevator lobbies and their pres- more symposium, a special panel session building construction. The Board for the NFPA Journal May/June 1993 49 - Coordination of Model Codes and the closely related. If a pressurization system control capability for the continued safe Department of Justice (DOJ) are rushing can keep elevator hoistways substan- operation of elevators during a building to establish codes and regulations, but tially clear of heat and smoke, why not fire for double the normal rush-hour there is no one authority to establish a use hoistways as vertical risers to pro- evacuation time and loads carried. It also humanistic approach to implementing vide duplicate and remote electrical places the responsibility for cooling ele- them. power supplies during emergencies? The vator controls with the most concerned failure of nonfire-resistive,single or clus- parties-the elevator manufacturers or Technical problems tered power supplies has resulted in cat- installers. There are still both technical and opera- astrophic losses in several recent high- Few people have had as much opera- tional problems to overcome. The techni- rise building fires. Hoistways can be tional experience in high-rise building cal problems are heat, smoke, water, and better constructed to protect both a fires as Elmer Chapman, retired chief of electric power reliability, most of which building’s occupants and the electrical the New York City Fire Department, who were addressed at the NFPA meeting in power that is needed to descend eleva- was one of the panelists at the New New Orleans. tors for their safe egress. Orleans session. His extensive field expe- Stairwell pressurization has been in For electrical power reliability during a rience led him to develop 13 criteria for use long enough to be a proven method lire, expensive large-capacity, space-con- safe elevator design (see sidebar). of minimizing fire and smoke invasion of suming emergency generators are not the Members of the New Orleans panel that component of means of egress. The answer. The proper solution is duplicate, discussed human factors involved in the same engineering principles apply to ele- remotely run, fire-resistive power lines problem, as well as the hardware require- vator hoistway pressurization, and simi- fed from two separate substations where ments. In fire situations, mobility-im- lar success can be achieved if we recog- available, as in all large cities. paired individuals have no choice but to nize the differences in construction of However, emergency generators are use elevators or to wait in stairwell ref- stair and elevator shafts and their doors. still necessary in hospitals and critical uge areas either until the fire is con- Because most building codes still re- service facilities and for utility outages. trolled or until people can assist them quire venting of elevator hoistways, pro- Smaller units capable of running one down the stairsby using a wheelchair vision must be made to negotiate away elevator car per elevator bank in addition carry, for example. that requirement with the authority hav- to emergency lighting should be pro- There has been a successful 20-year ing jurisdiction, or to supply additional vided. campaign to teach people not to use pressurization air to compensate for that Another heat problem can occur in the elevators in fires, but there is a downside which is lost. The number of stair doors elevator machine room. Most high-speed to not using the elevators for those who open during a fire emergency has been elevators used in high-rise buildings have have a choice of elevators or stairs. the subject of debate and the cause of microprocessor controls that are temper- Longer evacuation time, physical effort design limitations. Fortunately, in the ature-sensitive at degrees varying from required to descend stairs, the potential case of elevators, the maximum design 85°F to 104°F. ASME A17.1, the Elevator for long delays, and fear of stairway condition is one open door (or more, if Code, does not mention air conditioning congestion all are important consider- there is more than one elevator in a in elevator machine rooms because it is ations. The need for phased evacuation shaft). considered a building design function. of public buildings by floors in order to On the other hand, stairwells, unlike Since no model code requires air condi- prevent congestion must be better publi- elevators, can be entered when you ar- tioning in elevator machine rooms, the cized, especially to building occupants. rive at the door. Therefore, it is abso- type and existance of air-conditioning Both occupant training and written emer- lutely necessary to provide lobby smoke equipment there is a local option. gency plans are vital to ensure safe evac- doors at every floor level to create smoke The problem may be compounded by uation. zones separated from the remainder of the fact that some fire department offic- The chairman of the New Orleans ses- the floor areas. Conventional, loose-fit- ers habitually switch off electrical and sion concluded that all the speakers, de- ting elevator doors generally permit air-handling equipment power when they spite the differences in their backgrounds enough air leakage into the lobbies so enter a fire building. Without cooling, the and experience, agreed that when the that a separate, ducted lobby pressuriza- microprocessor controls rapidly over- revisions needed to meet the full intent of tion system is unnecessary. heat due to normal ambient heat released the ADAAG are completed, not much Such a system effectively creates tem- from elevator motors, resistors, and more will be required to provide safe porary areas of refuge and keeps fire, transformers. Loss of cooling is a more evacuation for all building occupants un- heat, and smoke at bay until and unless frequent cause of elevator control failure der fire conditions. the entire floor area is overwhelmed by than is the direct effect of fire. fwe. This is an infrequent occurence, par- The elevator industry is aware of this ASME AW dortr ticularly during the early stages of a fire control sensitivity.A common solution is The ASME A17 Elevator and Escalator when at least one elevator car could to install internal thermostats to shut Committee considered every suggestion reach the fire floor to evacuate occupants down the elevator car instantly when the made by the 16 speakers at the Baltimore waiting in the elevator lobby. In a build- critical temperature is approached; there symposium. Each suggestion was re- ing with a well-maintained sprinkler sys- is a separate control panel for each car. viewed and assigned to one of 24 perma- tem, total floor involvement should never Stopping elevators is no help in evacuat- nent A17 subcommittees or to several occur. However, until the time comes ing people or in fire service operations, A17 ad hoc committees specifically cre- when all high-rise buildings are sprin- and it frequently adds the problem of ated to review and analyze them. klered and the sprinker systems are elevators stalled between floors. Some of the technical work has been tested semiannually, smoke will continue A patent is pending for liquid cooling completed, and a few proposed changes to be a major problem when fire occurs.