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#101369 03/11/07 08:07 AM
Joined: Dec 2003
Posts: 751
There is a difference between smoke detectors and smoke alarms.

Smoke detectors are part of a fire alarm system.

Smoke alarms are stand alone units that are required to be interconnected to alarm when any one of the units is activated. (for new construction)

Smoke alarms are required in residential occupancies.

Fire alarm systems are required in commercial applications.

Make sure you are using the correct part of your building code document for the occupancy being protected.

In other words, don't apply the rules for a fire alarm system's smoke detectors to residential smoke alarm situations.

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#101370 03/13/07 12:14 PM
Joined: Dec 2006
Posts: 43
Junior Member
You sadi:

"Smoke alarms are stand alone units that are required to be interconnected to alarm when any one of the units is activated. (for new construction)

Smoke alarms are required in residential occupancies."

we are building some duplexes which some units have four apartments in them. the smoke detectors are only tied together inside the unit not to a system...

i guess if your neighbors place catches fire and they are not at home you will just be own your own!

The drawing shows smoke detectors, and not smoke alarms.

I think these are two different devices.

thanks for the replies.


We all live under one King
#101371 03/13/07 01:25 PM
Joined: Dec 2003
Posts: 751
Even the design professionals make mistakes. Take a look at NFPA 72. The distinction is clear, and the requirements for each is just as clear. Also, every smoke alarm contains a smoke detector, so they are not entirely wrong.

#101372 03/13/07 05:18 PM
Joined: Aug 2003
Posts: 64
I have yet to find references requiring CO alarms, I am sure I am just looking in the wrong locations (we do have one jurisdiction in Utah that has a law requiring them in all residences).
The requirement in Utah comes from a statewide amendment to the building code that applies in all jurisdictions in Utah. The Utah amendments to the codes can be found in this document . An amendment to IBC (2006) Section 907.2.10 can be found in Section R156-56-704(24) of that document, and an amendment to IRC Section R313.1 can be found in Section R156-56-711(16) of the document. These amendments require CO detectors in all Utah jurisdictions.

#101373 03/16/07 11:24 AM
Joined: Jun 2002
Posts: 58
earlydean said it correctly.
The building codes have for a long time required smoke ALARMS. They were first required in hallways leading from sleeping rooms, and now in every room used for sleeping.
The carbon monoxide alarm requirement is creeping in to the "code" environment now.
We (Oxnard Fire Dept) in Oxnard, CA require CO alarms on each floor of any new residence. We do it as a "condition of approval" for any new residential development. We hope to have it codified as a local amendment to the CA building code, soon. Next, the IBC and IRC, and then the world.......
Here's an example from the year 2000:
Grandpa is making soup in a big pot on an old stove. The big pot blocks air from reaching the burner. CO happens. Grandpa and other family members sit down, pass out. One family member staggers outside and falls face down in the front yard. A neighbor see him and calls 911. Every one is rescued. Another few minutes and every one inside would have been dead.
We want CO alarms!!
We want them interconnected so noise happens throughout the residence.

#101374 03/17/07 09:11 PM
Joined: Mar 2007
Posts: 25
when wiring multi family condo buildings in md and washinton dc each condo has those hard wired single station smoke detectors (or combo smoke/co's)in them. they do not interconnect with their neighbor's system but are inter connected in that particular condo with 14-3(if you burn dinner you don't want to evacuate the whole building.) they are 120 volt and are powered by that homeowners panelboard. then we have a fire alarm system that is wired to the sprinkler system water flow switches, elevator lobby smoke detectors and pull stations, when any of these go off it will sound an alarm throughout the building--in each condo and in the main corridors, stairwells,etc. in high rise buildings they will only alarm the floor of alarm and the floor above and below the alarm.

#101375 03/19/07 11:55 AM
Joined: Oct 2000
Posts: 2,722
Broom Pusher and
My thinking was towards CO Sensors + Alarms in an Environment such as an Underground Garage - where if a CO Sensor is activated, an Alarm status is initiated, along with exhaust fans to vacate the CO.

The opposite woul occur if a Fire was detected - no exhaust fans turned on, but Alarm status would be initiated.


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!
#101376 03/21/07 06:53 PM
Joined: Mar 2007
Posts: 25
yeah, scott in that case i would agree. the co detectors would activate supply, exaust and associated circulator fans. you'd wire that control circuit through a PAM relay that is tied into the fire alarm system, that way the f/a is isolated from the co control circuit. so when there is a fire the f/a system would shut down the fans. at least that's how i've done them in the past. i've also wired switches in the fire control room annunciator so the fire marshall could override the fans. enabling the fire marshall to stand in the fire control room and either shut down or turn on the fans to clear smoke from the garage.

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