Avoid Costly Mistakes

The model building code treats campus dormitories as residential occupancies. However, a dorm does not function the same as a commercial apartment building. In some cases, the architect has created a physical design to accommodate as many students as possible. Unlike a commercial apartment, the owner of a dormitory—normally the college or university—imposes many regulations on the occupants. A typical “dormitory apartment” might include three bedrooms with a center gathering room or study room, one or two bathrooms, and a small kitchen. The balance of the building may include a larger common gathering space or study area available to the residents of the dormitory and visitors.


Approaching a fire alarm system design and installation for a dormitory requires some thought and specific knowledge of applicable code requirements.


The 2012 edition of the International Building Code (IBC) classifies dormitories as a “Residential Group R-2” occupancy. In addition, the IBC contains the minimum requirements for fire alarm systems that affect this occupancy and states in part, “Fire alarm systems and smoke alarms shall be provided in … Group R-2 occupancies in accordance with Sections 907.2.6, 907.2.8 and 907.2.9, respectively. Single- or multiple-station smoke alarms shall be in accordance with Section 907.2.11.”


To start with, the IBC requires a manual fire alarm system in all R-2 occupancies. However, the IBC eliminates the required manual fire alarm boxes when the building is equipped throughout with an automatic sprinkler system and the occupant notification appliances automatically activate throughout the notification zones upon a sprinkler water flow. In this regard, the IBC requires every new dormitory to have protection from an automatic sprinkler system. So, the fire alarm system will need to monitor the sprinkler system gate-valve supervisory switches and all water-flow switches.


The IBC also addresses fire alarm system requirements specifically for a college dormitory. College and university dormitories that have interior corridors serving sleeping or dwelling units must have an automatic smoke-detection system that activates the occupant-notification system. The owner must install smoke detectors in common spaces outside of dwelling units and sleeping units, in laundry rooms, in mechanical equipment rooms, in storage rooms and in all interior corridors serving sleeping or dwelling units.


The IBC requires smoke detectors on each floor of a building to connect as separate zones, which may not exceed 22,500 square feet nor exceed a length of 300 feet in any direction. The fire alarm system installer must locate the remote annunciator (or zone-indicator panel) in an approved location. The visual-zone indication must lock in until an authorized person resets the actuated fire alarm system. Operation of the audible notification appliances’ silencing switch must not cancel the visual annunciation. Depending on the heating, ventilating and air conditioning system design, the IBC may require smoke detection, and it requires the installation of carbon-monoxide detection wherever fuel-burning appliances exist.


As you can see, the minimum fire alarm system design requirements come from the model building code. You may wonder, then, where does NFPA 72 2013, National Fire Alarm and Signaling Code, fit into the requirements? In Section 907.6, the IBC states, “A fire alarm system shall be installed in accordance with this section and NFPA 72.” It further requires all wiring to comply with the requirements of NFPA 70, the National Electrical Code, and NFPA 72.


NFPA 72 does not specifically require a fire alarm system installation for any building or occupancy. Such requirements belong to the sole purview of the building code. However, once the building code requires a fire alarm system, that installation must meet the requirements of NFPA 72.


Both the IBC and NFPA 72 contain important issues you must understand and that could affect your design and installation costs.


The first IBC requirement that affects your fire alarm installation is that “smoke alarms in dwelling units and sleeping units in Group R-2 college and university buildings shall be interconnected with the fire alarm system in accordance with NFPA 72.” To comply with the actual wording, you must use smoke alarms with dry contacts connected to the fire alarm system. 


However, you do not want to do this.


Smoke alarms have no provision for monitoring for integrity and generally do not possess the same quality as system smoke detectors. Furthermore, students can remove smoke alarms without the fire alarm system (or the authorities) knowing that this removal has compromised the fire protection.


A better design requires you to use addressable smoke detectors with audible bases. You program these initiating devices to perform as smoke alarms. Upon actuation, only the sounder base operates and the actuated detector transmits a supervisory signal to the fire alarm system control panel without setting off the general alarm notification appliances throughout the building.


Another potentially costly requirement of the IBC derives from the text that all “dwelling units and sleeping units shall be provided with the capability to support visible alarm notification appliances in accordance with Chapter 10 of ICC A117.1. Such capability shall be permitted to include the potential for future interconnection of the building fire alarm system with the unit smoke alarms, replacement of audible appliances with combination audible/­visible appliances, or future extension of the existing wiring from the unit smoke alarm locations to required locations for visible appliances.” This requirement can prove particularly troublesome, depending on the authority having jurisdiction’s interpretation.


In addition, an NFPA 72 requirement that became effective on Jan. 1, 2014, states that all audible appliances provided for the sleeping areas to awaken occupants must produce a low-frequency alarm signal that complies with the following: “(1) The alarm signal shall be a square wave or provide equivalent awakening ability. (2) The wave shall have a fundamental frequency of 520 Hz ± 10 percent.”


Therefore, you must provide for a low-frequency audible signal in apartment bedrooms and living room areas because they may contain sleeping occupants. However, this requirement does not apply to the hallways, lobbies or other tenantless spaces.


Designing a fire alarm system for residential occupancies like college dormitories can prove challenging. As a contractor committed to excellence, you need to pay attention to all of the codes and standards that may apply to your design and installation to avoid costly mistakes. 


About the Author

Wayne D. Moore

Fire/Life Safety Columnist

Wayne D. Moore, a licensed fire protection engineer, frequent speaker, writer and expert in the life safety field, has been a principal member and chair of NFPA 72, Chapter 24, as well as a former principal member of NFPA 909 and NFPA 914. He is the...

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