Noelle Marquis

Hi-

We're designing a rocket stove for our house with a mass heater bench and bench-back built of cob and brick (we have lots of free brick from craigslist). The house is made of wooden stud construction, so we have left the barrel and burn tunnel 1.5' from any wood walls with insulation, shiny aluminum foil, and an air space behind it. I'd love feedback on the design, if you have some. This will be my first build, though I helped with one (mostly the cobbing, though). Not obvious in the drawing is the fact that we plan to surround the bottom 1/2 of the barrel with bricks (less radiant heat, but a little more child-proof) as well as 1/3 of the sides and the entire back that faces toward the wall. We would also put more insulation around the combustion chamber on the back side facing the wall, allowing most of the radiant heat to go in to the room.

Some feedback I already got was that we probably don't need so man twists and turns for the exhaust snaking through the brick/ cob wall. It goes back and forth 3 times each with the hope that it will be nice and cool by the time it reaches the top of the wall where it has less thermal mass between the pipes and the stud wall, but if fewer runs will work, and would leave more room for thermal mass, we can go that route too.

Some specific questions I have are what kind of radius do we need for the turns in order to keep a good draught. Also, would you recommend adding a pilot hole somewhere near the flue/ chimney to help create draught to such the smoke up before everything is really heated up so we don't have smoke back? If so, where would you put it?

Also, we plan to store adjacent next to feed barrel and wonder how much insulation or thermal mass we need separating the wood from the barrel so that the wood is nicely dried out but doesn't catch fire.

Any other feedback/ questions welcome!

Thank you.
Noelle

Thanks for sharing your experience, Fred, and your sketch. I'd love to see pictures and hear if increasing the radius of the 90 deg. elbows works to get a draught again. Good luck!
Noelle

One more question... I think we got inspired by all those lovely pictures of benches against walls and had a similar design in mind, forgetting that those were all cob houses. So... what if we replaced any wood studs within a few feet of the combustion chamber with steel studs so we weren't close to anything flammable. Could we then put our rocket stove by the wall? We have lots of free brick too, so we could face the wall with brick over the sheet-rock too if it would help (we'd put a couple of inches of pumice or vermiculite between the thermal bench and any wall containing wood.) Would that work?

Thanks again,

Noelle

Thanks for all the tips, Allen! I'll check that the stove pipe was assembled correctly. We have it covered now so that ash/etc doesn't fall into our living room. It probably needs a good cleaning. Not much in our house was well maintained when we moved in.

I understand that I need the rocket stove in the center of the room (although my dad is still questioning whether we could'nt just use a couple layers of cement board and fire brick between the barrel and a wall... do you happen to know the temperature that the surface of one of these barrels will reach, so I can convince him?) However, couldn't I just make my built in furniture wind over toward where the old flue is so that my new flue can just go straight up rather than using "t"s. My husband is 6'3 and I'm 5'10", so pipes at 5'10" is not ideal if I can avoid it.

Noelle

Okay. Thank you! So helpful, Allen!

If I dry stack brick etc around the rocket stove, will the barrel still be exposed enough to give off radiant heat to quickly heat the room? Or is it worth skimping on the radiant heat in exchange for safety... I have a 3 year old? Do I place it in the center of the room in order to maximize the distance from any flammable wood walls?

Noelle

Our ceiling are 8' tall, and we will probably use a 55 gallon drum, but possibly a 35 gallon one, so I think there will be around 5' vertical distance from the top of the barrel to where the flue goes through the ceiling. We may still have the rest of the 8" insulated pipe in the yard that connected the old wood stove up to the ceiling... right now it is cut off at ceiling level. Nothing else is feeding into the flue right now, and you cannot see sky through the opening now because there is some sort of cover (storm cap?) on it.

Thanks Allen! I'm so happy to have found this forum, because I never knew where to go with my rocket stove questions.

Noelle

The chimney is insulated metal pipe. It looks like it has an 8"diameter inside and a 10" outer diameter. It has no horizontal runs or elbows... just a straight shot from where the stove was through the ceiling, attic, and roof. There doesn't seem to be a damper. The house is old (1920s), but the former owner used the woodstove daily up until a year ago.

Thanks for your help, Allen, or anyone else out there that has advice on this matter!

Noelle

Hi-

We removed ourold, inefficient woodstove and want to build a rocket stove (and soon! Our house is cold!). We still have the old stoves flue in place (goes up through the attic and then up at least another 8-10 ft to clear the second story part of the house's roofline). I'd like to use it as our flue for the rocket stove, if I can, since it is already there, but am concerned about creosote and corrosion from water condensing in it. Is there a way that I can modify it to be safe and effective, or should I just make a different flue and close the old one up?

Thank you for any advice on this! I have Ianto Evan's and Leslie Jackson's book and took part in a short 1/2 day workshop on rocket stoves, but still feel pretty intimidated about building my own in an old wood framed house.

Noelle Marquis