I have a fire wall on a two-story building providing separation for purposes of having two control areas.

There is a small roll-up door on the 2nd floor (in the main egress corridor of the building) in the firewall that can be opened to bring up items from the 1st floor to the 2nd through a lift from the 1st floor.

Is it code compliant to only have smoke detectors in the immediate area of the roll-up door (on each side) trigger the fire pin that closes the door, or, does every single smoke detector (it's a large building) need to trigger the roll-up (fire) door to close?

I am not finding a concrete code section (IBC or NFPA) that all detectors need to trigger the roll-up door to close.

Again, it's a very large building with many detectors. Thanks in advance for any answers/feedback.

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A project I'm on has a lobby area with a 35-foot tall ceiling next to the elevator door. 

NFPA 72-2010/2013 Section 17.7.3.1.3 and 17.7.3.1.4 allows a smoke detector within 60-inches of the top of each elevator door to protect the opening. This can be used for elevator recall.

In addition to this smoke detector, do I also need one at the ceiling (35-feet) for normal coverage?

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Are manual pull stations required to have any specific level of illumination at all times provided by emergency lighting?

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For a smoke control stair pressurization system designed in accordance with IBC 909 and IMC 513, does the code require a duct smoke detector on the supply fan?

Does the installation of a smoke damper at the stairway boundary factor into this requirement? (i.e. IBC 717.3.3.2 requires a detector within 5 feet of a smoke damper). Normally this motorized smoke damper is closed and then automatically opens upon activation of a specific fire alarm signal.

NFPA 92 6.4.6.2 does require a duct detector on the stair pressurization supply fan; however, I'm unaware of a similar requirement in IBC/IMC. NFPA's intent is to detect smoke on the air supply and shut down the unit before smoke compromises the stairway.

For elevator hoistways that require smoke control, IBC 909.21.4.2 states to provide a detector. I would have expected a general statement in IBC 909.12 with the same intention as NFPA 92; however, I do not see a similar requirement in the IBC/IMC for stairways.

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Is a two way communication system required when an elevator is installed (only for convenience) but is NOT required or designed to be part of the accessible means of egress - assuming none of the exceptions in 1009.8 apply?

Refer to CBC 1009.8: "A two-way communication system complying with Sections 1009.8.1 and 1009.8.2 shall be provided at the landing serving each elevator or bank of elevators on each accessible floor that is one or more stories above or below the level of exit discharge."

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NFPA 72, 2016 Edition uses the phrase "2-hour fire-rated construction" in a few places; what does this refer to?

It's confusing to me since a variety of elements within the building could be 2-hour rated. For example, NFPA 72-2016 Section 24.3.13.7 states:

"Two-way in-building wired emergency communication systems shall have a pathway survivability of Level 2 or Level 3. Exception: Level 1 shall be permitted where the building is less than 2-hour fire-rated construction."

Buildings are not designated with a fire-rating, elements are. How do you interpret this?

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What is a building owner's responsibility to provide sprinkler system plans and calculations to new tenants and/or inspectors?

Is there any responsibility to provide these?

Code sections would be appreciated, thanks.

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Has anyone come across a dual riser (dual-feed) sprinkler system in an office tower, with only a single inspector's test?

What is the proper method of testing each flow switch?

In most cases, only the flow switch nearest the inspector's test will operate in a timely manner. Some inspectors will isolate and test, others believe the system should be tested under normal conditions with both control valves open.

Is the deficiency the lack of a second test connection, or that the flow switch doesn't operate within 90 seconds (or even 5 minutes)? Alternatively, is there no deficiency at all?

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We are designing a clean agent system for electrical rooms located within a high-rise building. We are proposing having dedicated clean agent releasing control panels for the electrical rooms, and a separate building Fire Alarm Control Panel.

Is it mandatory to connect fire/smoke dampers (and other shutdown devices) in the electrical room with the clean agent releasing panel, or can these be connected to the building fire alarm system?

Thanks in advance.

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We are working on a mass notification system design. We have always called for any speaker/strobes in close proximity to the microphone to be shutoff during live announcements to prevent feedback.

Is there an actual recommended distance away that all speakers located within this distance should be shutoff? 

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Does anyone have experience installing a heat detector in a cold environment (~ -40 degrees C or F)?

I'm thinking a rate-of-rise detector would probably be the right type based on what I've read but having problems finding a cut-sheet that supports that operating environment. Normally this type of space would get a dry sprinkler but some things have led to trying to think "outside the box" for this project. Thanks in advance.

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Under NFPA 72 fire alarm manual pull stations are required on both sides of grouped openings over 40-feet in width and within 5-feet of each side of the grouped openings.

What about grouped loading bays or loading docks? Are manual pull stations required on each side of grouped overhead doors?

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Any good software resources out there for predicting fire alarm signal audibility across walls and doors based on their attenuation values and ambient sound pressure?

​Editors Note: Another fire alarm question today, love it. Keep 'em coming! You can post any fire protection-related question using the "Submit Your Question" link below at any time.

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As a consultant, what level of detail do you go into for the line voltage (120v) fire alarm plans and wiring?

The line voltage is affected by loads / fuse sizes and affects the disconnect switch size. I'm wondering about the level of detail that an engineer should be showing versus leaving the sizing to the fire alarm and electrical contractors based on their specific system layout requirements.

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We have an auditorium project with a walkway that is constructed beside the seating area at the first and second levels. The second level has been provided with beam-type smoke detectors. 

There is a suspended ceiling below the walkway which is approximately 6-feet (2 m) from the wall. Do we need smoke detectors below this suspended ceiling?

The design currently has smoke detectors only inside ceiling void spaces below the walkway - is this in compliance with NFPA 72?

The fire alarm contractor is arguing that if a fire originates at the floor level below this walkway, it will be easily detected by the beam detector at the second level due to the smoke buoyancy. 
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We have a project where the AHJ is telling us they want the waterflow alarm to be silenceable. Our understanding under NFPA 13-2019 7.7 and 28.2.3.1 is that there must be an audible alarm within 90 seconds (per NFPA 72) and must continue until the flow stops, not when the fire alarm system silences the flow.

Are we correct in that waterflow is a non-silenceable event, by code?

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Are initiation devices (smoke detectors, manual pull stations, duct detectors) required to have individual labels on them showing the device address?

The project in question is military and is also subject to UFC requirements.

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NFPA 72 requires a battery test be run including removal of the main power supply, waiting the full-length standby time, then activating the fire alarm system for the full alarm time. After the alarm time, the battery voltage is required to be tested.

What is the pass/fail mark for the battery voltage?

In theory, if the battery output still has 20.4 V, then the last appliance on a NAC circuit would still get a minimum of 16 V and everything still functions correctly. I just can't seem to find a code reference whether 20.4 V is the correct voltage to use (where a voltage reading below 20.4 V fails the battery). 

Thanks in advance.

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I am a municipal fire inspector. We have a new high school, fully sprinklered, that has residential stoves in a classroom. These are protected with UL300A hoods.

Are these hoods required to be connected to the fire alarm?

Common sense would indicate that if there was a fire hot enough to release the UL300A system, that the building occupants could be in danger and the fire alarms should activate, however, I cannot find a code reference for this. The architect is saying the stoves are residential so only residential requirements apply.

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Should return air duct smoke detectors associated with a fan system close only the associated damper and shutdown the fan or close all dampers on the system (including supply return spill and outside air)?

How should outside air and spill air fire smoke dampers be controlled? Should these to be controlled by fire alarm?

Thanks in advance.

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I’m confused by the field of view intent of NFPA 72 for synchronization.

Do two adjacent rooms with a door between them each with strobe coverage require synchronization?

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Question for AHJs and inspectors:

Do you occasionally see fire alarm strobes mounted on the ceiling that appear to be for a wall-mounted orientation (e.g. they are rectangular and have the word "FIRE" on the side)?

I know some of these are actually for ceiling mounted applications but I've run across some that are wall-mounted only. I think the Wheelock brand might be an example? Stuff like this is hard to tell in the field for an existing building (with no documented cut sheets for what was submitted).

Anyone have tips or tricks for this?

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What constitutes a "drop" on a fire alarm Class A circuit?

NFPA 72 12.3.8.1 (2016 Edition): 
"The outgoing and return circuit conductors shall be permitted in the same cable assembly, enclosure, or raceway only under the following conditions:
(1) For a distance not to exceed 10 feet where the outgoing and return conductors enter or exit the initiating device, notification appliance, or control unit enclosures.
(2) Single drops installed in the raceway to individual devices or appliances.
(3) In a single room not exceeding 1000 sq ft in area, a drop installed in the raceway to multiple devices or appliances that does not include any emergency control function devices."

For this project in question an appliance is located approximately 12 feet away from a device. The circuit runs from the device, out 12 feet horizontally, down a wall a few feet, then back up and back to the first device. 

In my opinion, the outgoing and return circuit exceeds 10 feet so it would not qualify as Class A wiring. However, the contractor is calling this a "single drop" to an individual appliance, so he feels it qualifies as exception (2) above.

Is this considered a single drop if it's only serving an individual appliance?

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Our common CRAC Units (Cooling, Refrigeration and A/C) for data centers only cool the air directly from the data center and back into the data center.

Do these need to be shutdown with the use of a total-flooding clean agent system? 

If the CRAC unit is only exchanging air within the same space then I'm not sure what harm it would do if it's running during or after clean agent discharge. I'm curious if I'm off the mark here, thanks!

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When an elevator does not have an elevator machine room, where should the fire alarm relays for the elevator be located?

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