roy
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Posts: 38 
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Post by roy on May 20, 2009 6:30:37 GMT -8
as you can see im trying to figure out how to build a rocket stove into our oak framed wattle and daub cottage inthe welsh hills of aberystwyth.
stove pipe is expensive and i want to build a stove which will heat the house and our extension.
we already have around 5 meters of 6" pipe. if i run 2 flues joined by a tee section after the ash/ clearout chamber of equal length and diameter. the length around 20' each. the stove based on the 55 gallon oil drum and 8" riser tube in steel.
will this work?
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Post by canyon on May 20, 2009 7:34:45 GMT -8
I think it will. I guess I am assuming you will rejoin them before a single vertical stack at the end. A double vertical at the end would be interesting though!  |
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roy
New Member
Posts: 38
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Post by roy on May 20, 2009 8:33:21 GMT -8
it will probably be a double vertical.
also has anybody run a pipe under a stone floor. if so how deep do you need to go so it isnt too hot to walk on?
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red
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Post by red on May 21, 2009 11:01:35 GMT -8
hi roy
good news that someone in the uk is building rocket stoves, there is a course june 7 on rocket stoves in the uk which i'm going to. i'm keen on building them in the uk i recently helped a mason from norway build a masonry stove, as i'm a mason by trade i plan to start building them soon, its just getting my act together! i'm in machynlleth mid june i'd love to see your stove if it's finished ,let me know how you go on
regards red
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roy
New Member
Posts: 38
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Post by roy on May 21, 2009 12:38:03 GMT -8
red, where is the course? although im away that weekend.
i would love it to be finished by mid june, but im in the middle of building my solar water panels at the mo. the rocket stove may be ready later summer although a test in the garden once i get some bricks should be fun.
cheers roy
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red
New Member
Posts: 5
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Post by red on May 22, 2009 2:53:52 GMT -8
hallo roy the course is at the middlewood centre near lancaster, its only a day course but looks interesting if you go to LILI website more details will be found there. i'd love to know how you go on. personally i like the idea of the heat riser being made out of brick, maybe not as funky but lasts longer. i'd be interested in knowing where you get your cob if you use it. vitcas and a place in sheffield are supplies of refractory cement etc, they are both on the web, i found they were hard things to get hold of , good luck with the project!
regards red
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roy
New Member
Posts: 38
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Post by roy on May 22, 2009 12:42:34 GMT -8
the web site looks good. i will have a look at vitcas for bricks and cement. i hope to use the sub soil from our land. it looks as if it has around 20% clay. me and my 2 year old are going to test the soil with a mud pie tomorrow.
cheers
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Post by Donkey on May 28, 2009 9:35:18 GMT -8
[quote author=roy board=discuss thread=114 post=957
time=1242829837]as you can see im trying to figure out how to build a rocket stove into our oak framed wattle and daub cottage inthe welsh hills of aberystwyth. stove pipe is expensive and i want to build a stove which will heat the house and our extension.we already have around 5 meters of 6" pipe. if i run 2 flues joined by a tee section after the ash/ clearout chamber of equal length and diameter. the length around 20' each. the stove based on the 55 gallon oil drum and 8" riser tube in steel. will this work?[/quote]
Hmm... It just might work. Dicey though, lot's of things can go wrong.
Lets assume the following system: an eight inch rocket stove, stepped down to two six inch pipes running through seperate masses, then re-combine back to a single 8 inch chimney. An eight inch pipe has an internal cross sectional area of 50.24 square inches. Six inch pipe's area is 28.26 sq inch, with a combined area (of two six inch pipes) at 56.52 sq in.. This is a pretty good match, two six inchers together are only slightly larger in volume (6.28 sq. in.) which should make up for the added friction of more pipe surface area.
Two things to pay particular attention to.
Added surface area of two six inch pipes will transfer heat faster, leaving less for the chimney. It is totally possible, even likely that you can transfer so much heat to your house that there will be too little left over to run the chimney.
Pressure balancing throughout your system will be important. If there are more bends in one leg of the (six inch portion), longer runs, higher elevations or other inequalities you may experience problems.. Heat could run more down one leg than the other or perhaps the entire system could back up. Also as flue gasses cool, they contract. Contracted gasses means pressure changes, slower throughput downstream which could domino-effect backwards and slow the entire system. Careful pipe size reductions in appropriate places can remedy this problem. Perhaps your final chimney pipe could be seven inch instead of eight.. I don't know the formula for this, nor have I done extensive testing so it would be a touch-and-go operation, purely experimental. I understand that old-school mass stove builders have a rule of thumb for this, though I've been un-able to find the information.
I know of one instance at the North American School of Natural Building where flue-splitting was tried. They split flow between two seperate heated beds in a tiny cob duplex. The stove had numerous problems. One side was abandonned completely but it didn't repair. I'm sure there are serious mistakes in that stove FAR beyond the flow splitting problem as it's NEVER worked properly. It should be chopped out of the cob and re-done from scratch, though at this point that would be a HUGE job, not too much fun in the doing with large repairs to the building in the aftermath.
My best advice to you is build and EXTENSIVELY test this stove outside someplace before you commit to bringing it inside. I personally would love to see this done well, with all hurtles jumped. Feel free to use this forum as a place to ask questions and post solutions, etc.
I look forward to seeing your progress on this!
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Post by Donkey on May 29, 2009 23:39:30 GMT -8
Oops.. I kinda misread your post.. Also subconsciously (almost) answered bombaatu's question here.. They're kinda related questions.. Umm.. two flues to the outside would be tricky but why not give it a shot? Easier recombining them at the end, I'd say. It might be helpful to you to read the thread on gas volume if you haven't already.. |
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Post by bendything on Aug 12, 2009 0:15:07 GMT -8
So, if you were to run two 6" pipes, completely parrallel, through a shorter bench so as not to extract too much of the heat and then rejoin them with a 7" chimney you'd be toastie?
Just wondering as I have the same problem, my local recycle centre had (past tense cos I have it all now!) plenty of 6" pipe but no 8".
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Post by Donkey on Aug 12, 2009 7:19:03 GMT -8
Umm.. Yep..
More than likely.
But I caution you to TEST EVERYTHING BEFORE YOU SET IT IN STONE.
Test the ideas outside somewhere, then run the stove WHILE you build it.. TEST TEST TEST!
Nothing sucks quite like discovering a fatal flaw AFTER it's all set, the cob is dry and the finish plasters are on.
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