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Discussion Starter · #1 ·
I have an inspector requiring a CO detector at receptacle height on the inside of a house, next to the door leading to the garage. This is a remodel. Originally we had a combo smoke/CO detector in the hallway and that was fine. The owner got a second permit to construct a bathroom and bedroom in a portion of the garage. Now he wants a CO detector as I described earlier. My question is, have you done this before and did it tie into the smoke alarms or was it a stand alone unit. I know I can go online and find these products, but I'm curious as to where this requirement for a dedicated CO detector might have come from. This was told to me by the HO, as per the inspector.
 

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Hmacanada said:
I think I would talk to inspectors personally. Sounds fishy to me. Unless it is a building code rule there.
Agreed
 

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CO detector can't be more than 3' off the floor. I've never figured out the CO/smoke detector combo. Because smoke rises and and CO falls to the floor. So if it's a combo one or the other is going undetected if mounted close to the floor or in the ceiling.
 

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CO detector can't be more than 3' off the floor. I've never figured out the CO/smoke detector combo. Because smoke rises and and CO falls to the floor. So if it's a combo one or the other is going undetected if mounted close to the floor or in the ceiling.
I don't think that's true. Smoke rises, but CO blends into the air.. it doesn't really matter if the detector is on the wall, floor or ceiling. I could be wrong, but I wondered about it a long time ago.. does it rise or fall and the answer I concluded was neither.

Where I live we use all combo smoke/co's, and they all go on the ceiling.
 

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I don't think that's true. Smoke rises, but CO blends into the air.. it doesn't really matter if the detector is on the wall, floor or ceiling. I could be wrong, but I wondered about it a long time ago.. does it rise or fall and the answer I concluded was neither.

Where I live we use all combo smoke/co's, and they all go on the ceiling.
I've had the exact same question...Why do I see COs plugged into the wall, but also CO/smoke combos in the ceiling? I found the same answer you did, Osmosis is the answer!

Like wild leg said, within 10' (on a walking path) from a bedroom. Bet on it needing to be interconnected.
 

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FrunkSlammer said:
I don't think that's true. Smoke rises, but CO blends into the air.. it doesn't really matter if the detector is on the wall, floor or ceiling. I could be wrong, but I wondered about it a long time ago.. does it rise or fall and the answer I concluded was neither. Where I live we use all combo smoke/co's, and they all go on the ceiling.
I did the same a couple years back and same answer it disperses evenly with the rest of the air we breath.
I was told either height doesn't matter for co2.
They decided to make the combo units because heat may carry the smoke as well as the co2 up
 

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The thing is if you're awake you will get a headache and feel sick and probably do something about the CO poisoning. But if you're sleeping, you'll just stay asleep and die. That's why it's more important to have the detectors as close to the bedrooms as possible.. less important is the height.
 

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They make a big deal about height around here. I just put 2 in today and the inspector said put them close to the bedrooms but no more than 3' off the floor
 

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the CO is heavier if it is at the same temperature as the air. Unfortunately, since most CO generated is the result of some type of combustion, it initially rises since it is usually combined with hot air.
 

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CO detector can't be more than 3' off the floor. I've never figured out the CO/smoke detector combo. Because smoke rises and and CO falls to the floor. So if it's a combo one or the other is going undetected if mounted close to the floor or in the ceiling.
I hope they can provide this in writing. It is NOT in the NEC and not in the ICC that I know of. It's NOT in the NYS Resi Code this way.
CO is almost 99% neutral to air so it neither rises nor falls. ANY air currents due to temperature differentials will cause it to mix quickly.

They make a big deal about height around here. I just put 2 in today and the inspector said put them close to the bedrooms but no more than 3' off the floor
Again, sounds like inspectors wants rather than code required.
 

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I rebuilt my service a few years ago. When I pulled my permit, the inspector said to be sure and install a smoke detector in every bedroom.
It had nothing to do with the service change.
It's just required in my town
 

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This is the sheet that sits on the desk of the permit office for us to see when we come in
This is clearly a local amendment.
CO detector can't be more than 3' off the floor. I've never figured out the CO/smoke detector combo. Because smoke rises and and CO falls to the floor. So if it's a combo one or the other is going undetected if mounted close to the floor or in the ceiling.
That being said, the document itself is contradictory.
#4 says: carbon and smoke combos are accepted.
However
c. says: no more than 3' above the floor.

Smokes need to (basically) be at the highest point of the ceiling per ICC. How could both #4 and both be true?

I've never figured out the CO/smoke detector combo. Because smoke rises and and CO falls to the floor. So if it's a combo one or the other is going undetected if mounted close to the floor or in the ceiling.
This may be the reasoning that your local uses, but it defies both physics and chemistry.
 

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This is clearly a local amendment.


That being said, the document itself is contradictory.
#4 says: carbon and smoke combos are accepted.
However
c. says: no more than 3' above the floor.

Smokes need to (basically) be at the highest point of the ceiling per ICC. How could both #4 and both be true?


This may be the reasoning that your local uses, but it defies both physics and chemistry.
I couldn't agree with you more. I work in 7-8 different small towns around here within 30-40 mile radius and I have to wire each house in those cities different. Nothing major, there is only 1 city that goes strictly by what NEC says. The rest have their own little rules to try and throw you off.
 

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I rebuilt my service a few years ago. When I pulled my permit, the inspector said to be sure and install a smoke detector in every bedroom.
It had nothing to do with the service change.
It's just required in my town
There are few cities around here that were doing that. I had to add smokes and GFI's where required on a service upgrade, but they quit that after about a year. I didn't mind doing it because it was more money, but the biggest headache was trying to get the homeowner and the inspector at the house at the same time.
 

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Discussion Starter · #20 ·
heath124 said:
This is the sheet that sits on the desk of the permit office for us to see when we come in
Yours states not near a garage and my inspector wants it right next to the garage door.
 
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