smoke detectors.

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peter d

Senior Member
Location
New England
It's not an NEC issue. Smoke detectors are covered by your local building codes or from the local fire department /fire marshall.
 
..Oh and I think generally they have to be at least a foot away from walls, and if mounted on a wall, between 6 and 12 inches from the ceiling. Dont quote me on that - the instructions supplied with the smokes discuss placement. Again, these are local requirements, I dont know exactly what the IRC says.
 

bdarnell

Senior Member
Location
Indianapolis, IN
Occupation
Retired Engineer
NFPA 72 5.7.3 gives general guidelines for detector placement. In general, it's 4" from a sidewall if mounted on the ceiling and between 4 and 12 inches from the ceiling if mounted on the wall.
 

raider1

Senior Member
Staff member
Location
Logan, Utah
2003 IRC R313.1
Smoke alarms. Smoke alarms shall be installed in the following locations:

1. In each sleeping room.

2. Outside each seperate sleeping area in the immediate vicinity of the bedrooms.

3. On each additional story of the dwelling, including basements but not including crawl spaces and uninhabitable attics. In dwellings or dwelling units with split levels and without an intervening door between the adjacent levels, a smoke alarm installed on the upper level shall suffice for the adjacent lower level provided that the lower level is less than one full story below the upper level.

It also says that all smoke alarms shall be listed and installed in accordance with the provisions of "household fire warning equipment" in NFPA 72 (the 99 edition is referenced in the 2003 IRC). As stated earlier the installation instructions of most smoke detectors seem to mirror the requirements of NFPA 72.

But as stated by Peter d it is a local building code, check with the local building department to find out the requirements. I just posted the quotes out of the IRC and not all places use the IRC, and some have local or state amendments.

Chris
 

FrancisDoody

Senior Member
Location
Durham, CT
A note of interest for Connecticut

A note of interest for Connecticut

  • Connecticut has a requirement that smoke detectors shall not be wired into the bedroom AFCI circuit.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
Re: A note of interest for Connecticut

Re: A note of interest for Connecticut

FrancisDoody said:
  • Connecticut has a requirement that smoke detectors shall not be wired into the bedroom AFCI circuit.
Does that mean "not on any AFCI circuit?" That would be an NEC violation, no?



A smoke detector is utilization equipment, right? :roll: Meaning it's installed at an outlet, right? :roll:
 

Jim W in Tampa

Senior Member
Location
Tampa Florida
Re: A note of interest for Connecticut

Re: A note of interest for Connecticut

LarryFine said:
FrancisDoody said:
  • Connecticut has a requirement that smoke detectors shall not be wired into the bedroom AFCI circuit.
Does that mean "not on any AFCI circuit?" That would be an NEC violation, no?



A smoke detector is utilization equipment, right? :roll: Meaning it's installed at an outlet, right? :roll:

NEC says smokes are an outlet and because its in the bedroom it needs be on afci.As to if this is a good idea or bad depends on your view.Personally i think it is bit safer if not on them.Your weighing good with bad.The chances of the smoke causing an arc is slim to none .Should the breaker kick and battery is old it might not go off.To me the later is a bigger risk.However the good folks at nfpa decided for you .Hitler did this for people too. :wink:
 

peter d

Senior Member
Location
New England
Re: A note of interest for Connecticut

Re: A note of interest for Connecticut

FrancisDoody said:
  • Connecticut has a requirement that smoke detectors shall not be wired into the bedroom AFCI circuit.

I'd like to see the actual ammendment before I believe this.
 

dnem

Senior Member
Location
Ohio
Jim W in Tampa said:
I would prefer it left up to the person taking the risk,mr homeowner.
The problem with that concept is that residential projects are different in purpose from commercial.

In commercial projects the installation is according to use. So things like 2,6,&12 foot plug spacing [210.52(A)(1)&(A)(2)(1)] doesn't have to be followed. The install is according to use only. If the business moves, the next business might have to make changes to the electrical system and spend the money to set it up to match their new use of the space.

For commercial jobs, I can see allowing the customer great latitude in choosing placement and function of most of the system.

In residential dwellings the installation is not according to present use only. That house is to be wired for that customer/home owner and must also function adequately for every other owner that will live there for the life of the building. As the house is sold and resold over its life, each owner/renter does not and can not be expected to rewire the house. So the preferences of the residential owner is not as important as on a commercial building.

As an example, I inspected one house that had a hallway that was about 35 feet long. It teed off another hallway and feed all of the bedrooms in a wing. As I walked thru on the rough, I noticed no light(s) or switch(es) anywhere in that hallway. As I questioned the contractor about this, the homeowner appeared and told me that she didn't want any lights in the hall. She liked to walk around the house at night without the lights on and required her kids to do the same. But I explained to her that her house had to be:
wired for all present AND future owners/renters
safe from unseen tripping hazards for the present occupants [210.70(A)]

The contractor then asked me if he could put one single pole switch in the center of the 35 foot run. I told him that you would have to walk 17 feet in the dark to the switch to turn on the light and then either let the light burn permanently or immediately turn off the switch and walk another 17 feet in the other end of the hall in total dark. The switch would not have any function while you were in motion. The light would only be on while you were standing still. (This is an example of the occasional bizarre type of conversations that inspectors end up having from time to time)

What he asked was actually legal according to the one switch requirement of 210.70(A)(2)(a). I can't figure out why the 10 foot hall plug rule of 210.52(H) was never also extended to 210.70(A)(2) as a 10 foot hall switch rule requiring a minimum 2 switches (3ways).

Sorry, I'm getting off the subject.

My whole point was that preference counts for alot less in residential because the electrical system is considered mostly permanent unlike commercial where the system is commonly changed/reworked for each different business/occupant

David
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
4) carbon monoxide on lowest level


Why on the lowest level? If there is only one CO detector it should be outside the sleeping area. Most CO related deaths happen while the person is asleep.
 

dnem

Senior Member
Location
Ohio
infinity said:
4) carbon monoxide on lowest level


Why on the lowest level? If there is only one CO detector it should be outside the sleeping area. Most CO related deaths happen while the person is asleep.
I would think that most CO producers (gas furnace, gas water tank) are usually on the lowest level (basement).

Also CO is heavy and stays low. If a house has a stairway into a lower level in the garage, you always have to have a step up before the stairway down to block the CO from the cars from rolling into the lower level of the house or collecting in the bottom of the stairwell when the door into the house is closed.

The best spots for CO detection are:
in rooms with large gas burners like furnaces and water heaters
and also in common hallways in bedroom groupings.

David
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
I would think that most CO producers (gas furnace, gas water tank) are usually on the lowest level (basement).

Also CO is heavy and stays low. If a house has a stairway into a lower level in the garage, you always have to have a step up before the stairway down to block the CO from the cars from rolling into the lower level of the house or collecting in the bottom of the stairwell when the door into the house is closed.

The best spots for CO detection are:
in rooms with large gas burners like furnaces and water heaters
and also in common hallways in bedroom groupings.

David


You might want to read this from First Alert:

Carbon Monoxide Detectors - UL Standard

"According to UL Standard 2034, home carbon monoxide detectors must sound a warning before carbon monoxide levels reach 100 parts per million over 90 minutes, 200 parts per million over 35 minutes or 400 parts per million over 15 minutes. The standard requires the alarm must sound before an average, heathy adult begins to experience symptoms of carbon monoxide poisoning. The warning provides time to evacuate the premises."

PLACEMENT OF CARBON MONOXIDE DETECTORS IMPORTANT

Proper placement of a carbon monoxide detector is important. If you are installing only one carbon monoxide detector, the Consumer Product Safety Commission (CPSC) recommends it be located near the sleeping area, where it can wake you if you are asleep. Additional detectors on every level and in every bedroom of a home provides extra protection.

Homeowners should remember not to install carbon monoxide detectors directly above or beside fuel-burning appliances, as appliances may emit a small amount of carbon monoxide upon start-up. A detector should not be placed within fifteen feet of heating or cooking appliances or in or near very humid areas such as bathrooms.

When considering where to place a carbon monoxide detector, keep in mind that although carbon monoxide is roughly the same weight as air (carbon monoxide's specific gravity is 0.9657, as stated by the EPA; the National Resource Council lists the specific gravity of air as one), it may be contained in warm air coming from combustion appliances such as home heating equipment. If this is the case, carbon monoxide will rise with the warmer air.
For this reason, the makers of First Alert (R), the leading brand in carbon monoxide detector technology, suggests mounting the detector on the ceiling. This also puts the detector out of the way of potential interference, such as pets or curious children.
 

dnem

Senior Member
Location
Ohio
"If you are installing only one carbon monoxide detector, the Consumer Product Safety Commission (CPSC) recommends it be located near the sleeping area, where it can wake you if you are asleep."

I guess I assumed that the CO detector would automatically be interconnected with the smoke detectors as I've seen on every job I've worked on or inspected. Smokes in Ohio are required in every bedroom and required to be interconnected, so the interconnected CO would set off all detectors including the bedroom smokes. That was a bad assumption. I didn't even realize that I was doing it.

"Homeowners should remember not to install carbon monoxide detectors directly above or beside fuel-burning appliances, as appliances may emit a small amount of carbon monoxide upon start-up."

I should have added this precaution to my post. I would recommend a CO on the same level as the furnace and water tank and even in the same room if the room was very large, but keeping a distance is a good idea for the reason they say. My CO detector in my basement (which is where my furnace is) saved my families lives one night when the furnace exhaust pipe was disconnected from the furnace by the roofer. The first cold night after my new roof was put on, the detector saved our lives.

"carbon monoxide is roughly the same weight as air (carbon monoxide's specific gravity is 0.9657, as stated by the EPA; the National Resource Council lists the specific gravity of air as one), it may be contained in warm air coming from combustion appliances such as home heating equipment. If this is the case, carbon monoxide will rise with the warmer air."

I don't quite get this thought. I know the step up in the garage stairway to a basement is a CO block and I've seen the fumes from the car hang low and get stopped by that step. There's something missing from this picture and I don't know what it is. I don't understand why they would say that CO is the same weight as air and rises with warm air. Even in the winter, in a garage filled with freezing air, my warm car exhaust always stays low, it never climbs to the ceiling.

What's missing from this picture ?

David
 

jimport

Senior Member
Location
Outside Baltimore Maryland
Occupation
Master Electrician
David,

I believe the requirement that garages be lower than the living space is to keep gasoline fumes, which are heavier than air, from entering the living areas.

Also, the car exhaust contains a great deal of water vapor which would affect its density.
 

dnem

Senior Member
Location
Ohio
Re: smoke detectors.

stew said:
anyone know where I can get the basic information on proper placement of smokies in resi?
Here are the requirements in Ohio. The following is our departments combination of our state code OBBC R313 and UL listing specs which are based mostly on requirements found in the Fire Alarm Code NFPA 72.

I don't know how this will compare to the requirements in other states. Ohio doesn't have any requirement for CO detectors.

Residential Smoke Detector Requirements
Power & Wiring
120 volt supply with battery backup
2 wire Romex from AFCI protected circuit to one detector and 3 wire Romex interconnection between all detectors
Room Location
Flat ceiling rooms:
On ceiling 4 or more inches from wall
On wall 4 to 12 inches between top of detector and ceiling
Sloped ceiling rooms:
Within the triangle formed by the ceiling, walls, and an imaginary plane located 3 feet from the peak
but at least 4 inches from any corner
House Locations
Must be in all locations listed below
1] One in each bedroom
2] One in each common area/room within each bedroom grouping
Area Location: If there are soffets, headers, roll-off edges, or ceiling air return intakes between the detector location and any bedroom door, then the detector must be within 10 feet of that bedroom door
3] One on each floor that does not have any bedrooms
Exception: Two floors that are offset by only ? of a flight of stairs can both be protected by one detector on the upper floor

David
 

dnem

Senior Member
Location
Ohio
jimport said:
David,

I believe the requirement that garages be lower than the living space is to keep gasoline fumes, which are heavier than air, from entering the living areas.

Also, the car exhaust contains a great deal of water vapor which would affect its density.
jimport

I think you've hit on the answer
Thanks
 
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