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HomeMy WebLinkAboutB06-0196 AMR#1101 Convention Center Dave Sjte 650 71 PJA t as Vegas, NV 84104-2001 USA ROLF JENSEN & ASSOCIATES, INC. www.rioinc.eom FIRF F'4. Tt ~tl:a:j;dry,)iT!i`:5 +1 702-699-5391 Fox: +l 702-644-5534 ADMINISTRATIVE MODIFICATION REQUEST Four Seasons Hotel Vail, Colorado Tows of Pall AMR #1 0' RICE COPY N-' 01SEZ Exhaust Fire and Smoke Damper Elimination '7 b Introduction: Shafts within a building provide a means for vertical transfer of fire and products of combustion if not properly protected. The International Building Code (IBC) 2003 edition requires protection of shafts with fire-resistive construction based on the building construction type and the amount of floors being served. For this project, 2-hour fire-resistive construction of vertical shafts is required. Openings in shafts are also required to be protected to prevent migration of smoke and products of combustion from transferring to upper floors. Where ductwork penetrate shafts, fire and smoke dampers are typically required. However, the IBC recognizes alternative means to protect these penetrations. These include metal sub-ducts and continuously operating exhaust fans. Code Section: Section 716.5.3.1 of the 2003 IBC, establishes the requirements for penetration of shaft enclosures by ducts and air transfer openings, when the shaft enclosure is permitted to be penetrated. Code Requirement: Section 716.5.3.1 of the 2003 IBC requires penetrations of shaft enclosures by ducts and air transfer openings to be protected with approved fire dampers and smoke dampers installed in accordance to their listing. © 2007 Rolf Jensen & Associates, Inc. All Rights Reserved E on NONE 0 ON EEEEEEEEEEEE ADMINISTRATIVE MODIFICATION REQUEST V31063 - Page 2 FOUR SEASONS HOTEL February 21, 2007 TOILET EXHAUST FIRE AND Issued Final July 20, 2007 SMOKE DAMPER ELIMINATION Exception 1.1 of this section allows the elimination of fire dampers at penetration of shaft enclosures by steel exhaust sub-ducts that extend at least 22 inches vertically in exhaust shafts provided there is a continuous airflow upward to the outside. Exception 2.1 of this section also allows the elimination of smoke dampers on shafts serving bathroom and toilet exhaust openings in Group B occupancies; provided the building is equipped throughout by an automatic sprinkler system, the shaft is equipped with steel exhaust sub-ducts extending at least 22-inches vertically, the exhaust fan is at the upper terminus, the fan is powered continuously with the provisions of Section 909.11, and maintains airflow upward to the outside. Code Intent: Section 716.5.3.1 requires both fire and smoke dampers at duct and air transfer openings in the shaft wall. The fire damper is required due to the penetration of a fire-resistance rated shaft, and to limit the migration of smoke to other parts of the building via the shaft. The code recognizes that a continuous airflow upward will create a negative pressure in the shaft as compared to adjacent spaces, thereby minimizing the spread of hot gases and smoke from the shaft. Request: To allow the elimination of smoke dampers for kitchen, clothes dryer and toilet exhaust shafts serving hotel guest rooms and residential units for the Four Seasons Hotel as allowed for Group B building occupancies by Section 716.5.3.1, Exception 2, 2006 IBC. Justification: The Code recognizes the elimination of smoke dampers in continuously operating exhaust shafts for Group B occupancies. This is due to the ability of the continuous exhaust system to create a negative pressure within the duct which will limit the migration of smoke outside the shaft on upper floors. It also recognizes that Group B occupancies do not contain sleeping areas where people are not able to immediately detect a fire, should they be asleep. ADMINISTRATIVE MODIFICATION REQUEST V31063 - Page 3 FOUR SEASONS HOTEL February 21, 2007 TOILET EXHAUST FIRE AND Issued Final July 20, 2007 SMOKE DAMPER ELIMINATION Regardless of the building occupancy classification, establishing a continuous exhaust in a shaft to create a negative pressure relative to adjacent spaces to the shaft will still limit the migration of smoke outside the shaft on upper floors. The intent of the code for protection of the shaft is still maintained using the provisions of this exception for Group R occupancies. The ICC recognizes this condition as the 2006 Edition of the IBC now allows smoke dampers to be eliminated at penetrations to shaft enclosures for both Group R and B occupancies. The same criteria applies for the 2006 Edition as required under the 2003. The negative pressure created within the shaft by the continuously operating fan provides for protection of the shaft from smoke as it is unlikely that smoke will spread to other floors once it enters the shaft. The upward flow of air will create a condition that effectively provides the same level of protection as the installation of a smoke damper. The sub-duct provided to eliminate the fire damper also provides additional protection for smoke migration from the shaft to the room, as smoke would need to travel out of the negatively pressurized shaft down through the sub-duct to enter the room. The continuously operating fan in accordance with Section 909.11 will provide for reliability of the fan as would be required for smoke control systems. These fans will be connected to the buildings emergency generator to provide the required secondary power supply. This provides a level of protection consistent with the code for protection of the shaft. ADMINISTRATIVE MODIFICATION REQUEST V31063 - Page 4 FOUR SEASONS HOTEL February 21, 2007 TOILET EXHAUST FIRE AND Issued Final July 20, 2007 SMOKE DAMPER ELIMINATION The use of this exception on the residential unit clothes dryer, kitchen and toilet exhaust systems does not reduce the level of protection to the building occupants, even though they may not be readily able to detect a fire condition. Each residential unit will be equipped with monitored smoke detectors so that a fire within a guest room or residential unit will report on the fire alarm system. This will allow in-house personnel to investigate the situation should the fire not be of sufficient size to activate the automatic sprinkler system within the room. Monitored detection within each room provides early warning not only to the occupants of the room, but also to in-house staff who can investigate the cause of the alarm. The residential areas of the hotel are also provided with automatic sprinkler protection throughout as required by Code. Quick response sprinklers are required within each residential unit, including the condominiums, timeshares, employee housing and hotel guest rooms and suites. The quick response sprinklers will also provide early detection and suppression of a fire that may occur within a residential unit. This will assist in evacuation of floors that may be affected by a fire within a residential unit, whether it is not occupied or if the occupants are asleep. In addition to the monitored residential unit detectors, some of the stairs that serve the residential and hotel guest room wings will be pressurized. These include stairs A, B and C. These stairs will assist in evacuation of the building under fire alarm conditions within the building. They will also allow for fire department responding personnel to assist in the evacuation of the building, since they will provide access to all levels of the residential unit floors. The configuration of the building also allows for two sets of elevators to serve each of the residential floors. These elevators essentially serve each of the two wings where residential units (condominium units, timeshares and employee housing) and hotel guest rooms and suites occur. The elevators are of sufficient size to allow for fire department staging and will assist in emergency operations. These elevators will have pressurized hoistways to reduce ADMINISTRATIVE MODIFICATION REQUEST V31063 - Page 5 FOUR SEASONS HOTEL February 21, 2007 TOILET EXHAUST FIRE AND Issued Final July 20, 2007 SMOKE DAMPER ELIMINATION the impact of smoke that may migrate into the shaft and transfer to other floors. Summary: This request provides a level of protection and life safety that meets the intent required by Code. Regardless of the building occupancy classification, when built in accordance with code exception requirements, the elimination of the smoke damper at the penetration of the exhaust shaft enclosure the level of protection for life safety afforded by the code is met. This is also recognized by the 2006 Edition of the Code. Monitored detection within each room also provides for early warning in the event a fire occurs within a residential unit or hotel guest room when it is not occupied or the occupants are asleep. This early warning helps mitigate the concerns of the model code in the elimination of smoke dampers for residential occupancies. ADMINISTRATIVE MODIFICATION REQUEST V31063 - Page 6 FOUR SEASONS HOTEL February 21, 2007 TOILET EXHAUST FIRE AND Issued Final July 20, 2007 SMOKE DAMPER ELIMINATION We respectfully request your approval. Upon approval, this document will become an attachment to the Fire Protection Report prepared for this project. Prepared by: ROLF JENSEN & ASSOCIATES, INC. O Jaion Miller Reviewed by: Date by Town of Vail Chief Building Official 6 o7- Date ,,.r 'eu-z-e- Vail Fire and Emergency Services Fire Marshal ~5e? Date AJV/TD:av/ba V31063/AMR 1 - Shaft Exhaust FINAL 07-20-07