I hope you'll get some good answers, but by and large, Permies.Com is a fabulous resource for rocket stoves and wood heat as a broad topic, but there's not a whole lot of traffic around custom woostoves.
So be our pioneer! Share your progress; we'll be excited to see it.
I've built 2 downdraft style or batch style stoves. Both where the hopper, main chamber gets 500 ish.
1 big issue, is seems to be the middle of the burn, where you are compelled to add more fuel, and the smoke either comes out, or likes to light up too much.
By lighting up, I mean secondary burn in your face. I had to add a bypass to my second stove to vent first, then open door.
This is the big safety issue with a large feed area, translates into large gas pocket. You will have to train her to not rush opening door.
Both resemble the low exit at coals level. Both were a huge reduction in wood being used.
I have a 10 foot run of stainless chimney liner, that is exposed before ducking up into chimney itself. so, minimal loss out top.
I'm doing a new design. wont' be done till end of jan.
I know there are likely other diy wood stove heaters out there on the web, (with secondary combustion chamber and air supply), but this is the most complete one I've seen:
Its not for rocket scientists but you might need to experiment a bit. Looking at and getting measurements from, a newer model stove that has the secondary combustion chamber with secondary preheated air supply would be your best bet. If you have a wood stove sales outfit nearby, it might be worthwhile to visit them.
I'd been thinking of doing a retrofit myself, but I'm still looking for a suitable stove. I think there's two basic options for modifying an existing stove.
One being to modify the interior like in the link I posted. The other would be to add a deflector/reducer inside to limit the primary burn and prevent the drastic 30% or so increase in heat. Then add an insulated external secondary combustion chamber sans rocket stove style heat riser and add a preheated air supply to either option. (Preferably ducting the air from outside through an insulated duct.)
At least that's my thoughts on the matter. Hopefully when it warms up here in spring, I can locate a stove and
go to work on it.
I hope you can keep those of us interested informed on your progress
Jason Parrish wrote:hello all. i am building a wood stove to replace the one that has succumed to age in my house.i have a two story house,barn style. my last stove i built was based on a scandinavian stove.it served well. however,on really cold spells it was not up to the task of heating the house. i am looking to build a stove that will hold a good ammount of wood for burning through the night,also, it must be able to run mildly and efficiently.i have been looking at downdraft designes,like the newer outdoor boilers,and stoves with rear baffles that force the smoke close to the coals at the bottom rear of the stove. i am a millwright/welder by trade and have heavy fabrication skills,so building the stove wont be a problem. other concerns i have are, what is the correct mix of secondary air to primary air in the firebox,or should it be adjustable to suit how the wood is burning? And it needs to be easy to operate so my wife wont have to be fighting with it while iJason am on the road working. i know this seems like a tall order, but i have faith in you guys. thanks,Jason
Jason, A Large amount of wood that will last thru the night. I have put a lot of wood in my stove and it has lasted 7 hours. I have also had smaller amounts of wood that has lasted 7 hours.
Depends on many different things.
Yeah type of wood, moisture content, dampener settings and loading wood sideways for longer burns etc, can all prolong or shorten burn time/heat output. Personally, the fewer times I have to fuss with a stove, the better.
If that means I have to experiment in order to get the stove I want, then that's what I'll do. Hopefully when the time comes I'll have researched some more and have the benefit of not repeating other peoples mistakes.
I just like the look of this stove.