Engineering Manual o.. - HVAC.Amickracing

SMOKE MANAGEMENT FUNDAMENTALSALARMDETECTORSINITIATINGPANELALARMPROCESSOROPERATOR’SCONSOLEFANTO ADDITIONALREMOTECONTROLPANELSCOMMUNICTIONSBUSREMOTECONTROLPANEL 1DAMPERFLOWSWITCHREMOTECONTROLPANEL 2ENDSWITCHSMOKE DETECTOR(NFPA SYMBOL)FIREFIGHTERS’SMOKE CONTROLSTATION (FSCS)M13026Fig. 6. Typical Smoke Control System Meeting the Requirements of UL Standard 864 and NFPA 92A.The following discussions cover smoke control applicationsfor building zones, stairwells, and large areas including mallsand atria. Each of these discussions conclude with a typicaloperational sequence complying with UL Standard 864 for thesmoke control system illustrated in Figure 6.Products utilized in smoke control and management systemsshould be ULI labeled for the following applications:— DDC Panels: Smoke Control Equipment.— Building Management System/Fire Control System:Critical Process Management, Smoke Control, or FireControl Unit EquipmentZONE PRESSURIZATION CONTROLThe objective of zone pressurization is to limit the movementof smoke outside the fire or the smoke control zone by providinghigher pressure areas adjacent to the smoke zone. Zonepressurization can be accomplished by:— Providing supply air to adjacent zones— Shutting off all returns or exhausts to floors other thanthe fire floor— Exhausting the smoke zone (also aids stairwellpressurization systems by minimizing buoyancy andexpansion effects)— Shutting off, providing supply air to, or leaving undertemperature control all supplies other than thoseadjacent to the fire floorA smoke control zone can consist of one or more floors or aportion of a floor. Figure 7 illustrates typical arrangements ofsmoke control zones. The minus sign indicates the smoke zone.The plus signs indicate pressurized nonsmoke zones. In theevent of a fire, the doors are closed to the fire or smoke controlzone and the adjacent zones are pressurized. In the example inFigures 7A and 7B, the floors above and below the smoke zoneare pressurized. The application in Figure 7B is called a pressuresandwich. In Figures 7C and 7D, the smoke zone consists ofmore than one floor. In Figure 7E, the smoke zone is only apart of a floor and all the rest of the building areas arepressurized. Smoke zones should be kept as small as reasonableso control response can be readily achieved and quantities ofair delivered to the nonsmoke zones can be held to manageablelevels.+++–+++(A)++++++–––++++++(C)++++++SMOKEZONESMOKEZONE++++++(E)+–+(B)+++–––+++(D)++–+++SMOKEZONEC5154Fig. 7. Typical Zone Pressurization Arrangements forSmoke Control Zones.The practice of exhausting air as a means of providing higherpressure areas adjacent to the smoke zone should be examinedcarefully. Exhausting air from the fire floor may tend to pullthe fire along and cause flames to spread before they can beextinguished.ENGINEERING MANUAL OF AUTOMATIC CONTROL 167