Smoke detector location inside bedroom

C

chrisexv6

Active Member
Any tips on where to locate a detector INSIDE a bedroom?

I would naturally go for dead center, but I have ceiling fans in each bedroom, in the dead center of the ceiling. So right in the center is out, and Im assuming I dont want an alarm where it could be affected by the stream of air from the fan either.

Should I stay away from door/window openings as well?
 
Typically I have seen them above/close to the entry door, I guess with the theory that the smoke would roll in from other rooms, and set them off as fast as possible.
 
Avoid the fan or potential fan if it gets installed in the future. Must not be within 36" of a bathroom door or supply duct. All points on the ceiling within 21' are within the rated coverage area of the detector. Now for the typical best location, 2' inside the entry door. Why, because you will never need to move furniture to install or service the detector.
 
Also it is supposed to be a minimum of 4 inches from the wall or if it is a gabled ceiling keep it down away from the junction point. The air in the angles between two walls tends to be stagnent so a room needs a lot more smoke in it before filling the "crotch" space. Centered over the door a couple feet into the room is an ideal location for most any bedroom. It would probably be one of the first places in a room to get smokey and it is easily serviced since, as mentioned, there is never any furniture there.
 
Lou Apo said:
Also it is supposed to be a minimum of 4 inches from the wall or if it is a gabled ceiling keep it down away from the junction point. The air in the angles between two walls tends to be stagnent so a room needs a lot more smoke in it before filling the "crotch" space.
Click to expand...

That is an old code requirement and was eliminated. It is now the favorite "gotcha " question to trip people up in class.

Sent from my Galaxy Nexus using Tapatalk
 
gizzmo said:
That is an old code requirement and was eliminated. It is now the favorite "gotcha " question to trip people up in class.

Sent from my Galaxy Nexus using Tapatalk
Click to expand...

Installation instruction sheets say to do this. Frankly, they don't look very good when smashed into the corner, function or no function impairment. Not that they look good anywhere, but they look very "uncomfortable" when wedged into a corner. Plus, every article I have ever seen on the subject says it is best practice to keep the more than 4 inches away. So do what you want, but I put all of mine about 2 feet or more away from a corner, centering them in some way when possible for a more aesthetic and balanced look.
 
gizzmo said:
That is an old code requirement and was eliminated. It is now the favorite "gotcha " question to trip people up in class.
Sent from my Galaxy Nexus using Tapatalk
Click to expand...

Not true,I would verify your reference, unless there is a change in '10 I'm not aware of. The NFPA still recognizes the 4/12" rule for sidewall mounting and 4" from junction for wall/ceiling. NFPA 72 2007, A.5.6.1

The reason for this is smoke rolls as it comes up a wall and the triangle made by the dimensions 4/4" and no more than 12" down, is where the dead air space is. Sidewall mounting on a gabled wall or similar is similar to above, however the dimension is 3' down from the ridge, so anywhere in that triangle, provided the other cited dimensions are maintained is acceptable.

The truth is, contrary to your post in #3 would be the center of the room, and I'm unclear where you're getting the 21' figure, as most detectors I am aware of are listed for a 15' spacing, 30' diameter for 100% coverage. Servicing is a factor, however code does not recognize furniture or fixtures for servicing a detector, but common sense is the deciding factor.

Depending on the room/door, usually centered 12" out from the door on the ceiling, or in an offset door situation, I've done 12X12" from a corner. You want to avoid near a window or strong draft area, so usually that means towards the inside walls of the room. I personally try to aim slightly behind where most doors open into a room so it's not the first thing seen when entering a room.
 
DELInstallations said:
Not true,I would verify your reference, unless there is a change in '10 I'm not aware of. The NFPA still recognizes the 4/12" rule for sidewall mounting and 4" from junction for wall/ceiling. NFPA 72 2007, A.5.6.1

The reason for this is smoke rolls as it comes up a wall and the triangle made by the dimensions 4/4" and no more than 12" down, is where the dead air space is. Sidewall mounting on a gabled wall or similar is similar to above, however the dimension is 3' down from the ridge, so anywhere in that triangle, provided the other cited dimensions are maintained is acceptable.

The truth is, contrary to your post in #3 would be the center of the room, and I'm unclear where you're getting the 21' figure, as most detectors I am aware of are listed for a 15' spacing, 30' diameter for 100% coverage. Servicing is a factor, however code does not recognize furniture or fixtures for servicing a detector, but common sense is the deciding factor.

Depending on the room/door, usually centered 12" out from the door on the ceiling, or in an offset door situation, I've done 12X12" from a corner. You want to avoid near a window or strong draft area, so usually that means towards the inside walls of the room. I personally try to aim slightly behind where most doors open into a room so it's not the first thing seen when entering a room.
Click to expand...

Smoke detectors are listed for 30' spacing which means that the detector should be no further 1/2 its listed spacing from the wall. If you use this spacing of 15' from two walls the distance from the corner would be 21'.

When I was stating the 4" from the wall was an old code requirement, I was implying that the most recent NFPA 72 code dropped this requirement. I do agree that it looks goofy crammed into the corner though.

Sent from my Galaxy Nexus using Tapatalk
 
gizzmo said:
Smoke detectors are listed for 30' spacing which means that the detector should be no further 1/2 its listed spacing from the wall. If you use this spacing of 15' from two walls the distance from the corner would be 21'.
When I was stating the 4" from the wall was an old code requirement, I was implying that the most recent NFPA 72 code dropped this requirement. I do agree that it looks goofy crammed into the corner though.
Click to expand...

That distance would suffice for spot detection only, not an install mandated to have 100% detection, and I've really never seen an inspector mandate such an install, only the addition of detectors in long hallways or if the main living space has a bedroom and the standard location for the smoke would be far removed from the area adjacent to the bedroom.

 
DELInstallations said:
That distance would suffice for spot detection only, not an install mandated to have 100% detection, and I've really never seen an inspector mandate such an install, only the addition of detectors in long hallways or if the main living space has a bedroom and the standard location for the smoke would be far removed from the area adjacent to the bedroom.
Click to expand...
DELInstallations said:
Not true,I would verify your reference, unless there is a change in '10 I'm not aware of. The NFPA still recognizes the 4/12" rule for sidewall mounting and 4" from junction for wall/ceiling. NFPA 72 2007, A.5.6.1

The reason for this is smoke rolls as it comes up a wall and the triangle made by the dimensions 4/4" and no more than 12" down, is where the dead air space is. Sidewall mounting on a gabled wall or similar is similar to above, however the dimension is 3' down from the ridge, so anywhere in that triangle, provided the other cited dimensions are maintained is acceptable.

The truth is, contrary to your post in #3 would be the center of the room, and I'm unclear where you're getting the 21' figure, as most detectors I am aware of are listed for a 15' spacing, 30' diameter for 100% coverage. Servicing is a factor, however code does not recognize furniture or fixtures for servicing a detector, but common sense is the deciding factor.

Depending on the room/door, usually centered 12" out from the door on the ceiling, or in an offset door situation, I've done 12X12" from a corner. You want to avoid near a window or strong draft area, so usually that means towards the inside walls of the room. I personally try to aim slightly behind where most doors open into a room so it's not the first thing seen when entering a room.
Click to expand...

NFPA 72 2010 A.29.8.3 " The conclusions of the Kemano Study and FPRF Smoke Detector Spacing Requirementts Report (2008) have determined revisions to smoke alarm and somoke detector mounting within 4 in. of a flat ceiling/wall corner are now acceptable."

NFPA 72 2002 A.5.7.3.2.3(E) "For smooth ceilings, all points on the ceiling shall have have a detector within a distance equal to 0.7 times the selected spacing"

If a detector is located in the center of a 30' x 30' room it would be 15' from each wall and 21' from the corner. The entire room would have full coverage and not spot coverage. 30' X 0.7 = 21'

I think that we both like this stuff too much.
 
NFPA 72 2010 has not, nor is it going to be adopted within the states I install/service in. From what I have heard, a lot of other juristictions are also rejecting 2010.
 
DELInstallations said:
NFPA 72 2010 has not, nor is it going to be adopted within the states I install/service in. From what I have heard, a lot of other juristictions are also rejecting 2010.
Click to expand...

There are several recognized code bodies and it is typical for AHJ to adopt or not adopt several years after the fact. Some of these code bodies are even in competition with each other. In many cases the other code bodies will reference areas of NFPA 72 even if they haven't adopted the full document. It will be likely be years before many states and municipalities even consider adopting the 2010 NFPA, My area is still using 2002. I did find it interesting that you suggested my comment was untrue and I should check my references, and then cited NFPA 72 as your source.
 
gizzmo said:
There are several recognized code bodies and it is typical for AHJ to adopt or not adopt several years after the fact. Some of these code bodies are even in competition with each other. In many cases the other code bodies will reference areas of NFPA 72 even if they haven't adopted the full document. It will be likely be years before many states and municipalities even consider adopting the 2010 NFPA, My area is still using 2002. I did find it interesting that you suggested my comment was untrue and I should check my references, and then cited NFPA 72 as your source.
Click to expand...

I was referring to the documentation that is next to me, which is NFPA 72, '02 and '07, which does not recognize the locations in relation to dead air space that you referred to in the '10 NFPA 72. My area of the county doesn't adopt sections of the NFPA or NEC, it's an all or none item with the AHJ making the more stringent decisions of what they'd like to see. Residential is typically cited as a combination of both those codes and then citing typically BOCA, however the IBC has also come in a few cases.
 
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