2 Smoke Alarm systems?

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davedottcom

davedottcom

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I'm working on a bid for a rather large home, (7,400 sq ft) I met with the builder and owner to ask some questions and was told the smoke alarms will be installed by the "Alarm Company".
Are AC/DC smoke alarms also required in addition to the "Alarm System" smoke alarms?
I've never run into this situation before!

Dave
 
Re: 2 Smoke Alarm systems?

The company I used to work for wired a 30,000 sq. house. In addtion to low volt burglarm alarm, stereo. intercom etc. there was a low volt smoke alarm system. We still had to install line voltage interconnected smokealarms as usual. The city refused to make an exception to only have low volt units. The NEC does not cover smoke alrms, in my area it is in the building code and the building inspector/dept. makes the call. I would call the AHJ to see if they will allow you to skip the 120v smokes. Hope that answers your question. :)
 
Re: 2 Smoke Alarm systems?

My area uses the International Fire Code, and both systems would Not be required.

Definately check with your local building inspector or fire marshall.
 
Re: 2 Smoke Alarm systems?

I would like to add that I thought the decsion by my AHJ was was totally stupid considering the low volt fire detction system that they used was superior to any 10 dollar 120V smoke alarm. Oh well as the saying goes "you cant fight city hall"
I heard the builder say he was taking all our smokes down after the Final. I always say "What you do to your home AFTER I leave is your business. (I make a note however about it so I can remember if there is ever a lawsuit)
 
Re: 2 Smoke Alarm systems?

suppose the homeowner terminates the "alarm monitoring service" contract (or fails to pay and gets shut off). where is the SD protection then?

a heat detector / SD is a welcome addition to any monitored residence however, LV only would probably not be such a good idea.
 
Re: 2 Smoke Alarm systems?

Originally posted by msd:
suppose the homeowner terminates the "alarm monitoring service" contract (or fails to pay and gets shut off). where is the SD protection then?

a heat detector / SD is a welcome addition to any monitored residence however, LV only would probably not be such a good idea.
Click to expand...
The monitoring service is an add-on, and has nothing to do with the function of the low-voltage smoke detectors/alarms.

Do a search on 'smoke detectors' on this site.
I, for one, am all for the low voltage smokes. We do alot of large homes that only use this system.

As with anything, the system must be installed correctly as per IFC. It is a far superior system IMO.
 
Re: 2 Smoke Alarm systems?

Just inspected a rough with the like situation. As a electrical inspector, I called in the fire department, never ran into this before either. We use life safety 101. My fire Chef required the fire alarm system to mirror the codes required by 101, that is one smoke in each bedroom, and one just outside of each, and one on every level. Each of these have to have two power supplies (ac w/ batt back-up), and produce an audible sound. The fire alarm system was only lacking the sounders in each bedroom, so the fire alarm installer is adding them in.
But on another situation, before I got this job, I wired side by side homes, a 36,000 sq.ft. home and a 28,000 sq.ft. home. The fire alarm installer did not put sounders in each of the bedrooms on either jobs, but yet the towns' inspector did not care. This subject is a call by the local ahj. I would make sure to give them a call...
 
Re: 2 Smoke Alarm systems?

I don't see that the IRC requires any partucular voltage, as long as they have a power source and a battery backup. As long as they all sound off together upon detection, they should comply.
 
Re: 2 Smoke Alarm systems?

Ryan which type of unit does the IRC require?

Smoke Alarms or a Smoke Detectors

Smoke alarms are typically the 120 volt self contained units that are interconnected and have a built in audible device.

Smoke Detectors are typically low voltage units without an audible device and need connection to a FACP.

Check the UL white book for more info.

[ August 09, 2004, 02:27 PM: Message edited by: iwire ]
 
Re: 2 Smoke Alarm systems?

I would think that in larger homes you would run into problems interconnecting all those 120v smokes since there is a limit on how many you can have on a "system".

A LV fire system controlled by a listed fire panel is far superior to individual 120v smokes. Horns and even strobes can be put in bedrooms and hallways as necessary to satisfy any code requirement. This is the way to go in those large homes or any home if they want to spend the money.

Any AHJ who rejects such a system in favor of $10 smokes is out of his mind! Would he require a commercial building to use them?

-Hal
 
Re: 2 Smoke Alarm systems?

I agree Hal, but if the code is written in a way that requires smoke alarms (not smoke detectors) the inspector does not get a choice.

Bob
 
Re: 2 Smoke Alarm systems?

But what's the difference between smoke alarms and smoke detectors? Smoke detectors, I would assume, have no local annunciation where a smoke alarm would incorporate it along with a detector in one package.

I think you have to look at intent here. LV smoke detectors installed as a system with horns and strobes (aka fire system) perform the same function and perform it better.

I believe the code is written to prohibit smoke detectors and a single annunciator or maybe just central station monitoring that is common in some places.


-Hal
 
Re: 2 Smoke Alarm systems?

yes, LV smoke detectors with properly placed annunciators are far superior to the smoke alarm interconnects. In my opinion, if you keep with the intentions of the IRC, and make it better, you should be fine. But if there was a fire, and for some act of the devil, the fire alarm panel did not signal the alarm, could the inspector find himself on the stand?
 
Re: 2 Smoke Alarm systems?

It seems like the low voltage system is foreign to alot of people.
Hal, I'm with you on this issue for sure.

The low voltage smokes signal the alarm just as the 120v. smokes do.

They are supplied by a 120v. source. Then stepped down to 12v.ac typical.
They have battery back-up (but not by a bunch of 9-volt batteries that typically get forgotten about) by a rechargeable battery.
 
Re: 2 Smoke Alarm systems?

I install fire alarm systems quite often, they are not foreign to me. :)

IMO it is not about that, it is about what the code spells out, in the UL white book you can find the definition of smoke detectors and smoke alarms.

IMO an inspector would be foolish to on their own decide that smoke detectors can be used in place of smoke alarms if the code requires smoke alarms.

I have seen a few posts that have said system smoke detectors are superior to smoke alarms.

How so?

Does one detect fire any better than the other? :)

Or maybe someone needs to submit a change proposal. :cool:

JMO, Bob
 
Re: 2 Smoke Alarm systems?

Does one detect fire any better than the other?

Actually yes in that there are a selection of detectors that can be better matched to the area being protected rather than the "one size fits all" homeowner special.

One of the requirements with fire alarm systems is annual testing by a certified company, how would that be meet in most homes?

Not any better than a HO testing or replacing those $10 ones.

Yes fire alarm systems have substantial batteries but they will fail and need replacement, is the average homeowner going to want to spend the money on the batteries? Can they change them without help?

Security systems have batteries also that need to be replaced as do regular smoke alarms. I would think that the company that installed the system would provide this service. The HO could do it also and it's probably a lot easier and less frequent than going around with a ladder replacing lots of 9 volt batteries that they have to go out and buy. You know what happens- it makes noise, they don't have a battery, so off the ceiling it goes.

Maybe the codes intent is to keep it simple and low cost for single family dwellings.

Maybe, but eliminating other and better options is the wrong approach.

-Hal

[ August 09, 2004, 08:34 PM: Message edited by: hbiss ]
 
Re: 2 Smoke Alarm systems?

Okay, I'll add my two cents worth here. There are obviously pros and cons to both types of alarm systems. If the 120 volt, interconnected type are used there is a limitation to the number of units you can install before installing an interface module (I believe it's 18 units for most mfrs.). In my opinion the customer benefits by this method in that they are not locked into any special service person or company to service the system. If a device goes bad it can easily be removed and/or replaced by either the homeowner or any qualified electrician. The down side is that it can be removed and NEVER replaced as there are no provisions for anti-tampering or prevention of permanent removal of the device. In addition, the electrical contractor has to take out the fire protection permit for this work and if, some time down the road, there is a fire the lawyers use the "shotgun" approach to filing law suits. If you did the work, you may be named in the law suit. And, if the house burns to the ground you will probably never know if any units were removed.

There are also benefits to integrated smoke and security alarm systems : 1) There is one central ac supply and a single, rechargable battery back-up that could last up to 24 hours; 2) The smoke detectors are supervised and will cause a trouble condition when removed; 3) High volume electronic sirens are placed throughout the residence instead of within each unit; 4) there is usually a greater system capacity for connected devices, 5) There can be a central office connection for alarm reporting although not necessary for a working local system; 6) the alarm installing company takes out the fire protection permit. As far as this type system being better than the 120 type is a matter of opinion. Both types of systems have either ionization and photo-electric type detection devices but you might get a better manufactured unit if you step up to a commercial grade system (rather expensive too).

The down sides to this type of system are: 1)when an alarm installation company installs their smoke detection devices in your residence you're usually "MARRIED" to them. Other smoke alarm devices may not be compatible with their system; 2) If the main control panel goes down for any reason (i.e lightening hit, voltage spike, etc.) you're out of business for both security and fire protection.

The fact that the AHJ made you install both types of units is ridiculous. If you built a 30K sq. ft. house and spent several MIL to do it would you want 2 smoke detectors installed on the ceiling at each location ??? Seems like over-kill to me. If I have the option I usually let the alarm installing company do the smoke detection portion of the job. Their install - their headache - their call-back when it malfunctions - their on the hook in case of a fire
 
Re: 2 Smoke Alarm systems?

Here in Connecticut, a low voltage smoke detector/alarm system can be used in lieu of a line voltage system in a residence.
 
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