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Rocket Stove size vs house size... and hybride with cast iron stove

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Hi there everyone!
First off, great site! great ideas! Best place on internet to be preparing for the end of the world!

I'm building a small straw/cob house in Qu├ębec/Canada. (20 feets by 20 feets) with two levels. No water, nor electricity... and it'S taking forever.. but it's fun!!! Love it!!
I'm planning to tryout a hybrid RocketStove and embeding an cast iron stove into a mass of clay. It seems that the main problem with the hybride is the heat leaks from the system, due by the iron stove itself. If we isulate the stove into a big mass, I think we can slow down those leaks. So... I'm wondering...

1- With a bigger combustion chamber, should my heat riser be higher? Should I'd be scared that the rocket reach the moon by using a conventional metal barel with a build up of pressure, and 4-5 logs burning? (seen the bread oven /rocket stove with the flames (of 4-5 branches) rises about 4-5 feets... impressive!

2- Can a rocket stove heat 2 lvl high? For now, I have a mezannine, but wondering if I should close it, in order to keep more heat on ground lvl, or leave it open to let the heat radiation flow more freely to the second level. And... if it's my ONLY source of heat (+ passive solar) , is the heat up time will be too long? Would two smaller rockets heat up the place faster?

Maybe, some of the questions have been already answered. I'm sorry if thats the case. I looked around, read a couple treads, but not all! So many info!

Thank you in advance!
Posts: 2
Location: Zone 6A Nova Scotia
forest garden trees urban
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Please let us know how well it works to cover a cast iron stove in cob! I don't think you'll have problems with pressure build-up, if the exhaust air has somewhere to go (and it sounds like you have a chimney) and if the cob is dry and there isn't water trapped somewhere. If you are adding thermal mass to your house, it will take a longer time to heat up and cool down, whether you have one stove or two. Most rocket stoves are used once a day to heat the house and then let the house hold the heat. What matters is your house insulation and the amount of thermal mass in the house, not the number of stoves.
Hope that helps!
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I have a question about the air intake for a RMH in a house. I'm sure its posted but I have not found it yet. I understand that the air velocity is high, doesn't this consume the warm air from inside the house and possibly draw cold air into the house from outside the building envelope? That is what happens with my drafty old fireplace, it is a net loss in warmth. Would it be reasonable to enclose the feedbox at the top and have an outside air intake for combustion near the bottom of the feedbox?


Posts: 196
Location: Perkinston Mississippi zone 9a
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Pj, The second video from the bottom of the page is about hybrid wood stove/ rocket. Hope it helps.
Posts: 3270
Location: Southern alps, on the French side of the french /italian border 5000ft elevation
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Jean Pierre, frankly, i'm not too sure using a cast iron stove is of any interest. You could always suround it with vermiculite, perlite or any other fireproof insulant. Then suround that with cob, but, your joints with the face of the stove will crack etc. Check that thread at donkey's http://donkey32.proboards.com/index.cgi?board=experiment&action=display&thread=511 I'm still working on the green one. I've managed to get the outside wall of my house hot to the touch, with the stove being two feet and a half away.
Jean-Pierre Paquette
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Ty very much Satamax for the thread... I really like the idea.
I have to admit that I'm lazy and having to feed the stove with tiny peices of wood would be a pain. I was thinking about the cast iron stove to be able to have a biger combustion chamber.
But hey! Why not 'make' the combustion chamber! Pretier, simpler. I like the comment about making a V shaped bottom to keep the wood closer when burning.
TY for hint!

Matt, I think it would be also a good idea to have an air intake outside and directly into the stove. But I haven't made any tests yet. But many mass heaters are using this principal.
I would think putting a grid in order to have the wood to be maybe an inch above the bottom of the stove would let enough air to flow... ...or maybe it should come from the front of the chamber to pull back the smoke onto the stove.
But is the air intake should be the same volume as the exhaust?? ... again, more testing, or better advice would be needed.

Thank you everyone, happy new year!
here's a drawing about how I would do an air intake... so, how did I do?
Filename: rocket-stove.bmp
File size: 1 megabytes
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