AMCA International inmotion Magazine - Summer 2012 - (Page 27)

A fire damper can be defined as “a device installed in ducts and air transfer openings of an air distribution or smoke control system designed to close automatically upon detection of heat. It also serves to interrupt migratory airflow, resist the passage of flame, and maintain the integrity of the fire rated separation.” Its primary function is to prevent the passage of flame from one side of a fire-rated separation to the other. Fire dampers are generally operated by a fusible device, typically a melting link. They are designed and tested under UL Standard 555: Standard for Safety for Fire Dampers, to maintain the integrity of the fire-rated separation. Smoke dampers are defined as “a device installed in ducts and air transfer openings of an air distribution or smoke control system designed to resist the passage of air and smoke. The device operates automatically and is controlled by a smoke detection system. They can be opened or closed from a remote fire command station if required.” Their primary function is to prevent the passage of smoke through the heating, ventilation, and air conditioning system, or from one side of a smoke-rated separation to the other. Smoke dampers are operated by either a factory-installed electric or a pneumatic actuator. They are controlled by smoke detectors and/or fire alarms. Smoke dampers are qualified under UL Standard 555S, Standard for Safety for Smoke Dampers. Combination fire/smoke dampers meet the requirements of both UL Standards 555 and 555S. For more information about the characteristics of smoke, fire, and combination fire/smoke dampers, refer to the article, “Fire Dampers and Smoke Dampers: The Difference is Important,” by John Knapp, in the 2011 issue of AMCA inmotion, which is available at www.amca.org/publications/magazine.aspx. UL Safety Testing The 2011 article briefly mentioned that smoke dampers must undergo extensive testing to obtain a label from Underwriters Laboratory (UL) under Standard UL555S. To classify their smoke dampers, manufacturers must send several different sizes of dampers to UL for tests that include, but are not limited to, cycling, temperature degradation, leakage and operation, as follows: Cycling Test: A damper must function as intended after being mechanically operated for 20,000 full strokes (closed and reopened). If the damper is to be operated as a smoke damper and a volume control damper, employing position devices that enable the damper to remain in positions other than fully open or fully closed, then it must go through 100,000 full strokes. As an alternative to the 100,000 full strokes, the damper may be cycled 20,000 full strokes and then 100,000 “repositioning” cycles of a minimum of 5 degrees. Temperature Degradation Test: The dampers used for this test are to be those previously subjected to the cycling test and prior to subjecting them to the leakage test. The elevated temperatures are to be in increments of 100 °F (56 °C), and the w w w. a m c a . o r g minimum temperature to be UL qualified is 250 °F (121 °C). The damper is exposed to the elevated temperature for 30 minutes in the completely closed position. After the 30-minute period and while at the elevated temperature, the damper shall function as intended while operated through three complete operation cycles. The damper is cycled by using the actuator that has also been subjected to the test temperature. All building codes in the USA require smoke dampers to have a minimum elevated temperature rating of 250 °F (140 °C). Leakage Test: The amount of leakage measured during this test shall determine the leakage class of the damper. For smoke dampers the leakage test is a continuation of the operation test. At the conclusion of the operation test, while the damper is in the closed position, the pressure and test temperature are to be maintained against the closed damper. The resultant leakage through the damper is then determined. AMCA Commissioning and Testing Guide A building’s fire protection or life-safety system is comprised of many types o f p ro d u c t s , i n c l u d ing, but not limited to, fire dampers, smoke dampers, combin a t i o n f i re - s m o k e dampers, and ceiling radiation dampers. All of these products must function properly as part of a comprehensive system during a fire or life-safety emergency. Proper installation, commissioning, and periodic performance testing are required to ensure these dampers function as intended in a fire emergency. AMCA International recently released a Guide for Commissioning and Periodic Performance Testing of Fire, Smoke, and Other Life Safety Related Dampers. The new Guide provides recommendations for the proper commissioning of fire and life-safety dampers and describes the appropriate intervals and methods for performing periodic performance testing of life safety dampers. A free copy of this guide is available in the Publications section of the AMCA website at www.amca.org/ publications/damper_maintenance.aspx. a m c a I n t e r nat I o na l inmotion Summer 2012 27 http://www.amca.org/publications/magazine.aspx http://www.amca.org/publications/damper_maintenance.aspx http://www.amca.org/publications/damper_maintenance.aspx http://WWW.AMCA.ORG

Table of Contents for the Digital Edition of AMCA International inmotion Magazine - Summer 2012

AMCA International inmotion Magazine - Summer 2012
President’s Message
Contents
From the Executive Director
Code Watch
News
The Role of Fan Efficiency in Achieving Energy Reduction Goals
Fan Motor Efficiency Grades in the European Market
Performance and Reliability Assurance of Custom Engineered and Manufactured Fans for Industrial and Utility Applications
Smoke Damper Testing and Maintenance for Service Life and Performance Assurance
Calendar
Advertisers Index

AMCA International inmotion Magazine - Summer 2012