Cutting holes in your ceiling or floor have you considered ceiling dampers?

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elkimmeg

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If you feel you must cut holes in your ceiling or floor , to distribute heat, please consider other safety consequences. There is a reason Smoke detectors are now required in bedrooms think, while sleeping you are most vulnerable. Let me weigh in as not an inspector for a moment. By the same token, free and direct passage of air in the vicinity of your wood stove heats your bedroom. The risk is smoke fire and gasses will also use this channel. You were safer before the passage, though a little colder. The question you have to ask yourself am I willing to risk or reduce safety for heat.
As part of my rough framing inspections I inspect for draft stopping and fire blocking. Why, Containment?
In the building codes there are 3 approved ways of purging a ceiling or floor all similar in nature. Floors and ceilings create a natural containment system, unfortunately stairways do not. That is why they are protected by smoke and soon Carbon monoxide sensors. All are special dampers.#1 Fire dampers they are activated by the presence heat from a fire or smoke, the detectors automatically close them to prevent infiltration of smoke and rapid acceleration of fire spread #2 Smoke Dampers they are closed upon activation of your smoke detection system. #3 Ceiling dampers usually have a spring loaded closer attached to a fusible link. ( usually lead or plastic) that melts once a certain temp is reached and closes the damper. {Btw the cheapest solution}

What to do? Purchase a ceiling damper. That restores safety but what about a return air supply?. The feed again is useless, without a return. It need separation distance to create a circulation flow so you will need another ceiling damper for your return
 
I did not know smoke detectors were required in bedrooms. I thought the common hall outside bedrooms was good enough. I bought a house 1.5 yrs ago and the Firedept. came to inspect and passed w/o smokes in the bedrooms. Maybe this is new code. I am in RI

JM
 
Elk...
Not to go off topic - your post makes a lot of sense, and I can certainly see the potential risks in opening up holes for the purpose of circulating heat - I have none in my house by the way.

Now I'm just curious, wouldn't your typical forced hot air/A/C ductwork pose the same potential threat? since they have a supply and return for air, couldn't a fire in one room of the house use this ductwork to accelerate the burn? Or are they considered more safe because the system is somewhat sealed? Is there any thought/discussion/need for changing code to include these heat activated dampers to shut down the flow of air in the event of a fire?

Not sure if that makes sense - just came to mind after reading this post and some of your other similar ones. BTW - I don't have a forced hot air system either
 
Harley,

Current fire codes do require the installation of fire control dampers and fire control measures that will shut off air handlers and other devices (Like individual fan coils) that move air in case of a fire.

This is commercial code I'm speaking of, but I'm imagine residential code also requires them. I'm not sure because all of the HVAC work I've done so far has been purely commercial.
 
I couldn't see fire penetrating ductwork easily. Now maybe if there is flexduct involved. Also I could see if the fire goes through panning inbetween the joists. I felt when I reinstalled my ductwork to follow clearances to the floor joists and I have the same heat trunk and ducting as I have my cold air return. Im most forced air systems, they are sealed. I tore out alof of old used ductwork that some time ago used the floor joists as ductwork, very unsafe. This situation had a large coal burner in the basement. All of that is now long gone.
 
Corie said:
Harley,

Current fire codes do require the installation of fire control dampers and fire control measures that will shut off air handlers and other devices (Like individual fan coils) that move air in case of a fire.

This is commercial code I'm speaking of, but I'm imagine residential code also requires them. I'm not sure because all of the HVAC work I've done so far has been purely commercial.

Thanks, Corie... the question was really showing my ignorance of how those systems work - I didn't realize there was some sort of damper in there. I've only seen a few forced hot air systems, and never looked at them closely - they just looked like open ducts to me
 
I did not know smoke detectors were required in bedrooms. I thought the common hall outside bedrooms was good enough. I bought a house 1.5 yrs ago and the Firedept. came to inspect and passed w/o smokes in the bedrooms. Maybe this is new code. I am in RI
JM

Not anymore, Im biulding a new house and smoke detectors are required in each bedroom as well as the central hallway and stairway/ loft. And they must be interconnected, if one sounds they all sound.
 
In our house, we have basically have one big return and feed duct that runs across the width of the house, perpendicular to the joists, and then a bunch of branches that run parallel to the joists in the spaces between them. These are covered by the sheetrock ceiling in the finished basement. As far as I can tell, all are closed pipes, nothing that is actually using the joist spaces themselves for ducts. Is this safe? OK per code?

Gooserider


laynes69 said:
I couldn't see fire penetrating ductwork easily. Now maybe if there is flexduct involved. Also I could see if the fire goes through panning inbetween the joists. I felt when I reinstalled my ductwork to follow clearances to the floor joists and I have the same heat trunk and ducting as I have my cold air return. Im most forced air systems, they are sealed. I tore out alof of old used ductwork that some time ago used the floor joists as ductwork, very unsafe. This situation had a large coal burner in the basement. All of that is now long gone.
 
Its safe and im sure its code. Alot of people when finishing a basement will build framework around the ductwork and drywall it. Even better if its insulated. As far as a fire concern, panning isn't the safest thing, not sure if code allows it on new construction. I have a woodfurnace tied into my ductwork so I had to follow duct clearances because of potential high temperatures. A gas or electric furnace shuts down around 200 degrees, but a woodfurnace could excede this so the space has to be greater to reduce the risk of combustion.
 
Unfortunately pan floor joist bays and wall cavities are permitted in residences for return routes. I have petitioned my stoate to consider automatic system shut down upon smoke detection.
Really it does not cost that much and no one has questioned the safety factor but at times change comes slowly. T^he automatic shut down is a lot cheaper than smoke damopers
Its already in the comercial code. If the NFPA and fire marshalls have their way, look for expanding sprinkler systems making their way into one and two familly dwellings
 
Corie said:
Harley,

Current fire codes do require the installation of fire control dampers and fire control measures that will shut off air handlers and other devices (Like individual fan coils) that move air in case of a fire.

This is commercial code I'm speaking of, but I'm imagine residential code also requires them. I'm not sure because all of the HVAC work I've done so far has been purely commercial.

I'm not saying they don't exist, but I've never seen a fire damper in a residential FA system.
 
Yeah I have to say that I haven't either BG. I would like to think that residential has caught up with commercial, but I'll bet it hasn't. All of the systems I've seen were older though, so anything is possible. For the added cost, which is so minimal for these fusible link dampers, I can't see why they aren't included. Same with the detector that shuts down the forced air system if it detects smoke in the ducts.

I would especillay like to see the latter included in all home units. That few extra minutes that the FA system shutting down buys you could be huge, and it doesn't seem like the cost is prohibitive.
 
laynes,
What are the clearances you kept when reducting your house? I've always wondered because I have a wood furnace too. My ductwork gets pretty hot, but never so hot that you get burned when you touch them. I would imagine that if it was over 200, it would burn you. But I don't have a probe to test it. Still, I wouldn't mind having the proper clearances.
 
If the surface temp of the duct is over 130 it will hurt to hold your hand to it. As for clearances, it's hard to say without documentation. Take a look at the Yukon Jack furnace installation diagrams I posted in the blower thread. They show at least 18" clearance from top of the WB plenum and supply duct for 3 feet. Then it can be reduced to 6" for the next 3ft of supply and 1" after that. I would also add a layer or two of drywall over the supply plenum + ductwork for the first six feet.
 
I have at least 4 inches from the joists. You can go 6" for the first 6 feet then go to 2" from there. Those are what most recommend. If its a stand alone furnace than most definetly at least 6" from the joists to the plenum. This is just a safeguard in case the power would go out and there were longer no blower(s) to distribute the heat. Im also going to insulate my ductwork eventually to help keep the heat since my duct run is so long.
 
Yukon Brunco and Fire Chief treat the supply plenum and first 3 feet with the same clearances as the stove, must be 18". This seems prudent considering the out-of-sight, out-of-mind nature of a furnace. But Caddy says 6". Anyone have a CharMaster installation manual handy?
 
What about headers? Every doorway in my home has a header (except the stairs...) but I would like to put holes in that neck of the woods... seems like the same safety issue... anyone know of any products for this type of venting?
 
Marty said:
What about headers? Every doorway in my home has a header (except the stairs...) but I would like to put holes in that neck of the woods... seems like the same safety issue... anyone know of any products for this type of venting?

Transoms were common before air-conditioning .
Over the years the transom was abandoned as a cost saving
trick, after all drywall is cheaper than hinged windows.
 
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