Air return system

Someone mentioned code issues. Can you tell me that the flexible duct is designed to transfere heat from a wood stove? Nowhere have I ever found that this use is an exceptable listing? Please educate me if you find one. The listings for flexible bducts are to be connected to a sealed conbustion system. No wood stove is a sealed combustion system. With non user secondayr air feeds, is not the deffinition of sealed. Remenber that heat from a furnace is from an exchanger, completely sealed from the fire chamber.
Flexible duct carry only a class A fire rating for the outer wrap. The iner wrap is plastic poly that is very combustiable.
What about containment? Containment of a fire or smoke saves lives The research supporting containment is overwelling.
In single familly dewllings, natural containment is your floors and ceilings. That 1/2" sheetrock has 1/2 hour containment value. This is especially important facillitating a fast safe exit. Studies also have proven you are safer sleeping with your bedroom doors closed.

The intent here is to distrobute heat to a bedroon from a wood stove. Again we are most vunerable while sleeping. That same heat passage, can also be an excellerated pasage for smoke co and co/2's, in your most vunerbable state. During rough frame inspections, we focus of draft stopping every wire duct should be draft stopped. Its code, But why? Containment.
Residential codes are more relaxed then comercial applications. If this were a commercial application, a smoke damper would be required in that line.. Tied into the general alarm system, to shut down, to contain the spread of smoke, again containment. The comercial air distrobution system may also be tied into the alarm system, triggering a system wide shut down, again containment.

Everything you are planning to do is counter to containment, even the very materials purposed, flexible ducts. I have challenged every mechanical contractor to prove me wrong. If I put a coke 20oz coke bottle under a fawcet and run the water 24 hours, how many oz will fill the coke bottle? Supply without equally engineered returns is useless. Especiall trying to introduce lighter warmer air into a cooler air enviorment . Common sense tells you its not going to happen. Truth is, you would be better served placing your in ducts fans in a return system removing the cooler heavier air, to make room for the warmer air to enter. Your return locatiions should be in the floor or close to them to take out the coolest air and to also draw the warm air down.

Then there is the issue of mechanically removing air in close proximity of your fuel burning appliance.. That appliance needs x amount of combustion air to opperate correctly and draft correctly. By removing air mechanically, you produce a negative pressure situation near that appliance. This negative pressure situation can cause your not so closed wood stove combustion chamber, to back draft spillage.. You just have increased the risk of drawing co and co/2 into your living space and now provided the means to transport them into your bedroom.

I purposely did not quote codes but explained how dangerous this practice can be, by using common sense.
If I went threw all the NFPA codes, mechanical codes, and manufactures listing,my scanner light bulb would burn out first. All wood stoves manufacture listings specs, are required to note the wood stove cannot be connected to your air delivery system. It is not designed to do so. IF you need convincing I read this yesterday in VC resolute Acclaim manual, when answering a chimney height issue. I can cut and paste that language or wording. So someone has never seen it in code? The installation manual is code. I suggest re reading it. There is also code concerning cutting unprotected holes in ceilings and floors.

Right now, I am working with my state and IBC, international codes, to adopt alarming in conjunction with the smoke alarm systems in residential codes. Doing this is not all that expensive.

The key is to remove the heavier cool air. the fan location should be on the floor, air flow directed in the direction of the stove
the warmer air will enter at the top of th doorway. As yo draw the cooler air out the fan will also act to draw in warmer air and draw it down. Many make the mistake of trying to force lighter warmer into colder heavier air . Really that does not work well.

I am fooling around with a 14 w fantech radon fan, model HP 2133, 134 CFM at 0 gage pressure. It is incredibly quiet. www.fantech.net