multi family fire alarm systems and/vs smoke alarms

[electrofelon]

A few things first. I dont know much about fire alarm systems. Where I learned the trade FA is a separate trade. I know some places electricians commonly do the FA systems but not here. Second I know the NEC doesnt cover placement, system requirements etc and that is more of a building code thing. So......

In your area, how are multi family buildings treated, specifically in regards to fire alarms and/vs smoke alarms? What I am talking more about is say buildings with 4-10 units, not high rises or big buildings. Say like what used to be a large single family house that was split up into apartments. I have seen these handled different ways, and things are rather lax here and many of the building officials dont know a whole lot. Here is what I have seen:

1. 120v smoke alarms in each unit, not tied between units. No central FA system.
2. 120v smoke alarms in each unit, tied between units. No central FA system.
3. 120v smoke alarms in each unit, not tied between units and a Central FA system with a heat detector and strobe in each unit.
4. Just a central FA system with no 120V smokes. not sure stations are heat or smoke.

So just real briefly (if possible) which are compliant and in what situations?

 

[gadfly56]

A few things first. I dont know much about fire alarm systems. Where I learned the trade FA is a separate trade. I know some places electricians commonly do the FA systems but not here. Second I know the NEC doesnt cover placement, system requirements etc and that is more of a building code thing. So......

In your area, how are multi family buildings treated, specifically in regards to fire alarms and/vs smoke alarms? What I am talking more about is say buildings with 4-10 units, not high rises or big buildings. Say like what used to be a large single family house that was split up into apartments. I have seen these handled different ways, and things are rather lax here and many of the building officials dont know a whole lot. Here is what I have seen:

1. 120v smoke alarms in each unit, not tied between units. No central FA system.
2. 120v smoke alarms in each unit, tied between units. No central FA system.
3. 120v smoke alarms in each unit, not tied between units and a Central FA system with a heat detector and strobe in each unit.
4. Just a central FA system with no 120V smokes. not sure stations are heat or smoke.

So just real briefly (if possible) which are compliant and in what situations?

1. Typical, especially if no common hallway.
2. Illegal, you can't run 120's between units.
3. Maybe, depending on the AHJ. You may need coverage in common hallways which I have seen with smoke alarms. It's becoming more common to drop a horn/strobe in the units, usually without the detector, or if a detector, usually a smoke. Detectors in the units are a pain because you need access to the units for the annual test and inspection.
4. Also illegal, even with separate notification. I tried this once and the AHJ shot me down.

 

[James L]

Second I know the NEC doesnt cover placement, system requirements etc and that is more of a building code thing.

It's not really a building code issue, just a different NFPA book.

NEC is NFPA 70
Fire alarms are in NFPA 72

 

[electrofelon]

1. Typical, especially if no common hallway.
2. Illegal, you can't run 120's between units.
3. Maybe, depending on the AHJ. You may need coverage in common hallways which I have seen with smoke alarms. It's becoming more common to drop a horn/strobe in the units, usually without the detector, or if a detector, usually a smoke. Detectors in the units are a pain because you need access to the units for the annual test and inspection.
4. Also illegal, even with separate notification. I tried this once and the AHJ shot me down.

Thanks. Why is #4 illegal? Cant you do anything with a low voltage addressable system that you can do with hardwired 120V smokes?

#4 is what I just saw recently and kinda what started this question. 4 units, I started wiring one of the units and the FA system had already been installed. I started wiring up 120V smokes but then got thinking there were a lot more FA locations wired than I was used to so I asked the owner to ask the FA guy if we needed line smokes, he said no. AHJ here just defaults to the FA contractor.

 

[gadfly56]

Thanks. Why is #4 illegal? Cant you do anything with a low voltage addressable system that you can do with hardwired 120V smokes?

#4 is what I just saw recently and kinda what started this question. 4 units, I started wiring one of the units and the FA system had already been installed. I started wiring up 120V smokes but then got thinking there were a lot more FA locations wired than I was used to so I asked the owner to ask the FA guy if we needed line smokes, he said no. AHJ here just defaults to the FA contractor.

It may have been a NJ thing. The AHJ pointed out that each tenant would have to have access/control of the FACP that served their unit per the Residential Code. I could and did design it to act just like 120 VAC units, with superior notification in my view, but "better" didn't mean "legal". I could put a separate panel in each unit, or go back to 120VAC smoke alarms. We chose "B".

I think it was around 2009 that NJ finally allowed you to put in a smoke detector system instead of a smoke alarm system. Up until then, if you wanted low voltage smoke detection you had to show a hardship, that you couldn't get all the coverage you needed within the limitations of the smoke alarms (max 12), or you had to put in the smoke alarms with the smoke detectors.

 

[James L]

Thanks. Why is #4 illegal? Cant you do anything with a low voltage addressable system that you can do with hardwired 120V smokes?

#4 is what I just saw recently and kinda what started this question. 4 units, I started wiring one of the units and the FA system had already been installed. I started wiring up 120V smokes but then got thinking there were a lot more FA locations wired than I was used to so I asked the owner to ask the FA guy if we needed line smokes, he said no. AHJ here just defaults to the FA contractor.

Each apartment is to be alarmed independently, and common areas alarmed as a unit.

I don't think it's an isdue of line- vs low-voltage

 

[electrofelon]

Each apartment is to be alarmed independently, and common areas alarmed as a unit.

I don't think it's an isdue of line- vs low-voltage

Seems it comes down to convenience/practicality, i.e not having someones burnt toast setting off the whole building. But OTOH maybe for safety you want everyone in the building knowing if there is smoke somewhere. That is why the #3 seems to be the best as "nuisance" alarms are limited but then if things get real bad the central system goes off. Not sure what the codes say about it.

 

[James L]

Seems it comes down to convenience/practicality, i.e not having someones burnt toast setting off the whole building. But OTOH maybe for safety you want everyone in the building knowing if there is smoke somewhere. That is why the #3 seems to be the best as "nuisance" alarms are limited but then if things get real bad the central system goes off. Not sure what the codes say about it.

NFPA 72®: National Fire Alarm and Signaling Code®

<p>1.1 Scope.<br />1.1.1 <br />NFPA 72 covers the application, installation, location, performance, inspection, testing, and maintenance of fire alarm systems, supervising station alarm systems, public emergency alarm reporting systems, fire and carbon monoxide detection and warning equipment...

www.nfpa.org

I can't find it right off, it's really been 15 years or more since I've read it. Chapter (article?) 29 is where I'd look first

 

[farmantenna]

I've done #1 , #3 and #4 for smaller buildings. Your requirements depend on the building code and not fire alarm code. I'm not an expert on the building code. Here in Massachusetts it depends on how many units.

I installed a complete low voltage addressable system with sounder bases and wall sounders in a group of 4 unit buildings. The units were independent of others and programmed as supervisory smokes. The manager wanted to be alerted of sd activation. Common hall had SD , Pull and horn strobe. They did not have sprinkler system.

A sprinkler system is required at specified unit count

 

[Fred B]

The local AHJ and county code, here requires a multiple unit dwelling to have an interconnected smoke/CO between all units up to ten units. Usually requiring a seperate common service the same as if having common having common hall/entry (landlord service) if units are metered separately. Over ten units it would require fire alarm system. Only caviatet is if each unit is fire wall 4 hr, seperated (side by side Duplex type not over/under) it can be viewed as separate buildings for smoke alarms installation.

1. Typical, especially if no common hallway.
2. Illegal, you can't run 120's between units.
3. Maybe, depending on the AHJ. You may need coverage in common hallways which I have seen with smoke alarms. It's becoming more common to drop a horn/strobe in the units, usually without the detector, or if a detector, usually a smoke. Detectors in the units are a pain because you need access to the units for the annual test and inspection.
4. Also illegal, even with separate notification. I tried this once and the AHJ shot me down.

Why is #2 illegal? Our local jurisdiction is requiring basically just that, to get the system requirements I just referenced.

 

[curt swartz]

The local AHJ and county code, here requires a multiple unit dwelling to have an interconnected smoke/CO between all units up to ten units. Usually requiring a seperate common service the same as if having common having common hall/entry (landlord service) if units are metered separately. Over ten units it would require fire alarm system. Only caviatet is if each unit is fire wall 4 hr, seperated (side by side Duplex type not over/under) it can be viewed as separate buildings for smoke alarms installation.

Why is #2 illegal? Our local jurisdiction is requiring basically just that, to get the system requirements I just referenced.

I believe the building code does not permit smoke alarms to be interconnected between dwellings.

You are also limited to a maximum of 12 interconnected smoke alarms so I have no idea how your AHJ can require up to 10 dwelling units have all alarms interconnected.