# cold air return to woodstove?



## Jredsjeep (Oct 27, 2010)

I am looking at revamping my woodstove area to update it to code. as the title suggest i am wondering if i can safely an legally add ductwork to feed my furnace cold air return to my woodstove. i would like to do this to try to get more even heat around the house. i live in a ranch house with open access to the basement so running the ductwork is not a huge deal. i am more worried about doing it right.

i dont want to set up something that will not meet code or cause a problem with safety if God forbid the house caught fire and i got denied insurance. 

i suppose optimumly i would tap into the cold air return on the furnace like mentioned and feed a duct to the bottom rear of the woodstove. this would then be fed through the back of the woodstove between the stove and heat shield where the blower would normally blow air through.

i did some searching and didint see anything like this mentioned in my owners manual or in general setting up woodstove instructions.

i am looking for something more permanent and cleaner than placing box fans around the house. can i do this safely and effectivly?


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## CWME (Oct 27, 2010)

I cut registers in the floor of my ranch. Some right above the stove and some at the other end of the house. The heat goes up above the stove and the "cold" goes down the other end. No fans or duct work needed here. House is pretty evenly heated.


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## blades (Oct 27, 2010)

Actual code reads that a cold air return for your regular furnace must be a minimum of 10 ft away from a solid fuel combustion device used as a space heater.


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## volks-man (Oct 27, 2010)

blades said:


> Actual code reads that a cold air return for your regular furnace must be a minimum of 10 ft away from a solid fuel combustion device used as a space heater.



if this is the case ^^^ then the o/p could add registers to the floor in the room where the stove is.
theory being that if you have more return air, moving out of that room toward the furnace return, the heat in that room must be moving too.

mind you that people have tried the woodstove-to-air return trick before.
depending on the size and output of the stove you will generally not get enough duct temperature to really 'heat' a house of any size. 
though, preheating the air, even a little, before it reaches the furnace can't hurt!


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## blades (Oct 27, 2010)

Yep, in a lot of cases the basement is not heated or insulated, and neither is any of the duct work. Therefore more loss than gain in that arrangement. Generally a simple fan on the floor to push or draw cold air from the area you want to warm will do more good. Or perhaps one of those doorway corner fans to push warm air in the direction wanted. I have a 10" oscillating fan about 3ft from the stove blowing at it. It does a fine job of mixing things up in the main living areas. As my bedrooms are in a separate wing ( 60's ranch) off a T shaped hallway, it is quite difficult to get a lot of heat from the stove back there as it is basically a dead end as far as air circulation is concerned. I would need to install ducting to provide a negative displacement in those rooms vs/positive in the stove location.


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## DSS (Oct 27, 2010)

My furnace guy told me to put a variable speed motor(~$300) on my forced air furnace and let the blower run on low speed 24/7. It draws very little power and it keeps the air moving in the house, and keeps the basement above freezing.

I haven't tried it yet but it seems to make sense.


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## CountryBoy19 (Oct 27, 2010)

blades said:


> Actual code reads that a cold air return for your regular furnace must be a minimum of 10 ft away from a solid fuel combustion device used as a space heater.



I could be mistaken, but I thought it was only 6 feet away...


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## RunNGun17 (Oct 27, 2010)

Not sure on how far away you have to be, I've always heard 10ft from guys on the threads. I'm an HVAC tech and I've seen returns directly over wood stoves only 3-4ft about the stove drawing in the hot air. Is it to code or legal, not sure.

My set up is a wood stove in a finished basement with my Heat Pump fan running all the time. I did do some duct work mods. so now my basement is now my "central return" which means all my returns in my house are closed down and I am now pulling 1000 cfm of return air from the basement to heat the house. My return is 20ft. away. I would have done the method of pulling it right off the top of the stove till I did my research and guys on here said not too. 

I would try and keep it 10ft or more. But heres the thing. If you are not pulling enough return air from the basement where the wood stove is, then you will most likely have problems heating the house. This is why I made the mods to the duct work and made the basement my "central return". Kind of like if your ranch has A/C in the attic you might have only one return in the hallway. That too is a "central return".


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## Jredsjeep (Oct 28, 2010)

thanks for the input guys, it sound like i am out of luck though. if i have to be so far away i assume that is to keep a fire from passing through the ductwork and spreading. 

i was just hoping for something more auto matic and cleaner than placing fans around the house. i was hoping to pull cold air from other rooms through the ductwork to be heated by the stove. not neccisarily preheat the air going to the furnace but that is a thought.

i might just have to look into running my furnace fan somehow to circulate air. it would probubly draw less than all the cealing fans we usually run.


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## blades (Oct 28, 2010)

ran the thermal gun through the house just before I left. Living room (stove location) 80, wall at end of hall 75, furthest bedroom floor 73. 30NC on low currently cooking silver maple. between 36-40 outside with high winds yet. Oh and about 1/2 of my storm windows are off as the painters are working on the place.


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## CWME (Oct 28, 2010)

If your basement is not insulated then that would be the best place to start. I have r-19 in the daylight basement walls, 4 mil vapor barier, 2" DOW R-10 foam board, all cracks sealed with window cauking.
Windows are foam spray sealed. Bulkhead now has a steel door at the bottom with the jam all sealed up with foam spray.

The sill pockets are getting foam spray here in a few weeks from www.tigerfoam.com.

When I have the $ for more foam board I will do the concrete walls next with that.

Total area being heated is 2800 sqft. Englander 50 snc rated at 2200 sqft on low is keeping the house 74-78 at night. Our nights have been getting into the upper 20s.

As previously mentioned I have registers cut above the stove and at the other end of the house. Working great with no fans.


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