Wednesday, March 18, 2015

Pre-Wire for ADA Adaptability in R2 Occupancies

What does it mean to pre-wire for future ADA adaptability?

The International Fire Code or IFC is where we look to find out what fire alarm requirements to follow when designing systems.  Specifically Chapter 9 "Fire Protection Systems".  If we dive deeper into section 907, we are informed as to what is required for each occupancy group.

For this article, we will be reviewing the requirements for an "R-2" occupancy.  As defined in the International Building Code or IBC, an R-2 group occupancy consists of: "occupancies containing sleeping units or more than 2 dwelling units where the occupants are primarily permanent in nature, including: Apartments Houses, Boarding House with more than 16 occupants, Convents, Dormitories, Fraternities and Sororities, Hotels (non-transient), Live/Work units, Monitories, Motels (non-transient), Vacation timeshare properties."

Since this article revolves around the requirements to pre-wire for future visual alarms, we will stay away from discussing the initiating side of the code.  Full requirements for an R-2 occupancy.

International Fire Code Section 907. Pre-Wire for Group R-2

Section 907. states "In group R-2 occupancies required by section 907 to have a fire alarm systems, 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 systems 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 is a major upgrade in comparison to a group R-1 occupancy such as Hotels and Motels.  In these facilities, the code gives us parameters as to how many rooms with visible alarms are needed based on the total quantity of sleeping units.

"So what does all this mean?"

In basic terms all living spaces within a group R-2 occupancy must contain the necessary wires, raceways and boxes to support the ability to upgrade to audible and visual notification throughout. ADA aside, our design must provide at least 75 dB in all areas of the quest room.  On top of this, your jurisdiction may now be requiring the fire alarm occupant notification to produce a 520Hz low frequency tone in all sleeping areas.  Find out more about 520Hz requirements.

A lot of fire alarm designers are confused to the actual requirements of this code section.  To be clear, it is the intent of the code to have a fully functional low frequency audible occupant notification system that can be upgraded with visual alarms without cutting walls, adding boxes or running new conduit.  All of the necessary wire or a conduit raceway must be in place to all living spaces, sleeping rooms and bathrooms within each living space.  As stated in the paragraph above, we need a minimum of 75 dB throughout the space.  To achieve this, it's typical to have a low frequency audible appliance in each sleeping room as well as the living space.  This design makes it easy to just swap out the low frequency sounder appliance for a combination low frequency and visual appliance. Don't forget that you will need a box and wire to each restroom within the guestroom.            

ADA section 4.28 "Alarms" gives us the requirements for visual appliances within ADA compliant areas.  Pay close attention to section 4.28.4 "Auxiliary Alarms" Units and sleeping accommodations shall have visual alarms connected to the building emergency alarm system or shall have a standard 110-volt electrical receptacle into which such an alarm can be connected and a means by which a signal from the building emergency alarm system can trigger such an auxiliary alarm.  When visual alarms are in place the signal shall be visible in all areas of the unit or room. Once a group R-2 living unit is upgraded to meet ADA requirements for visual alarms, you will need a low frequency audible tone of at least 75 dB throughout as well as visual alarms in all areas of the living unit.  This includes restrooms.

Side note: NFPA 72 2013 Table informs us of the candela rating required visual appliances installed in  sleeping areas.

Distance from the ceiling to the top of the visual appliance lens:
> or = to 24 inches = 110 Candela
< 24 inches = 177 Candela

This standard was put in place as smoke migrates to the ceiling in the event of a fire.  It is common sense that a more intense strobe flash would be required to shine thorough the thicker smoke found closer to the ceiling and still have the ability to awake a sleeping occupant.  This is why we are required to install a 177 candela strobe when located less than 24" from the ceiling.

Best installation method to accomplish ADA adaptability for Group R-2 occupancies.

Run a trunk run down the corridor with Notification Appliance Circuit (NAC) loops as well as a Signaling Line Circuit (SLC) pulled into a J-Box within the closet of each living unit.  It is best to pick the closet that contains the unit's breaker panel.  From this J-Box pull your notification circuit loop through all appliance locations.  In the event the room needed to become adaptable, simply splice your incoming/outgoing NAC loop through in the J-Box.  This way the notification field wiring loop within the living unit is separate from the rest of the existing building NAC circuits.  Install a single output remote power supply listed for fire within the closet and power up with a dedicated 120 AC circuit.  Use the SLC in the closet to install an addressable smoke detector and control module to protect and activate the power supply.  See the example layout below:

Group R-2 ADA Adaptability for Fire Alarm

Now keep in mind that these audible / visual notification appliances will need to activate via general alarm, floor alarm or an alarm from within the unit itself.  To activate the notification appliances from within the living unit, you could either install addressable system smoke detectors or connect addressable mini modules to the 120 VAC UBC smoke alarms.  The detectors or modules would activate the control module connected to the power supply as well as indicate a supervisory condition on the fire alarm control unit (FACU).