Richard Gurry

Thank you for the reply and posting the link to another who was tried it:)

when i said that everything else being equal the tallest chimney should have the best draw

I am not sure our terminology is the same. I understand that you are 100% right on the above quote, however the 'draw' comes from the heat riser, and I only have one. Do you mean the exhaust port with least resistance will support the most gas flow? The exhaust tubes (from what I understand) do not create 'draw'.

however that would be a function of Gravity 1st

Also, I am unaware of the role of gravity in a RMSH. Was this not covered in Ianoto Evans book?

Thank you.

p.s- I will draw up a diagram of what I have been thinking about to control 'exhaust zone selection' in my next post.

Maybe you could contact these people to find out what kind of phase change material they use.
http://www.joulies.com/
Closer to the same temperature, glad I remembered the kickstarter project.

Any one else here into distillation? Wine making? Beer making?

Ever thought of combining a still and a rocket mass stove?

Anyone want to run their engines off of ethanol?

Me Too!

Your right, it's not a negative. But it's also an easy fix.

Has no one attempted multiple exhaust ports yet?

Thank you all for the great points and tips about my post!
However I am too stubborn to throw this idea away. There is not a single problem that has been addressed which cannot be engineered out. Safety is rarely more than a few modifications away.

1.) Having the fire draft up the feed tube is certainly a problem, yet easily fixed. Simply put a lid with a small hole on top of the feed tube? Wouldn't this create a space of positive pressure due to the expanding gasses and humidity from the wood? A small hole would still let out humidity at a fixed rate (assuming a wood filled feed tube isn't enough). Secondly, I highly doubt this would be much of an issue beyond initially starting up the fire. Notice the heat riser is twice the height of the feed tube; Once a fire is started the path of least resistance is the heat riser in terms of BOTH flow rate and pressure difference.

2.) Regulating temperature of wood in feed tube. Gasification requires temperatures well into the high 300's Fahrenheit. What we need is a heat sink that acts as a thermal buffer to the fuel source. WATER? I say YES! Wrapping the feed tube with copper coils filled with water will regulate the temp well below gasification and double as a water heater. The bottom of the coil would be connected to a water tank, the top feeding into the same tank or a new one depending on your needs. No pump is needed obviously because of the thermo-siphoning effect.

3.) Having multiple exhaust ports.... Not one of you thinks this is viable? seriously?... From the stoves perspective having one zone open compared to another really makes no difference. And 'accidentally' opening more than one zone at a time will result in dangerous circumstances? I feel like I'm taking crazy pills. This is so EASILY be engineered out that it should be considered a 'non-issue'.

SORRY if this post offended y'all. I don't mean to be harsh, but come on..... lets be solution minded instead of obstacle minded. please?

"if you take two chimneys or two funnels, the taller one draws/drafts better every time"

This would be true if I had multiple heat risers. Draft comes from the pressure differentiation of the air inlet and top of the heat riser(this is why your exhaust outlet can actually be lower than your air inlet). Having multiple exhaust ports AFTER combustion is not the same as having multiple chimneys. I realize that I can only have one 'zone' open at a time, other wise the exhaust will follow the path of least resistance. We are not thinking of the same thing. When different zones are being used the impedance of the exhaust will be determined by the length/amount of J's & T's within that one zone; and each zone will be different.

Also, than you for the builders tip on insulation and cob. Last May/June we had single digit humidity!

Mark, from what I have read and seen in videos, you CAN burn logs, twigs, sticks, even bones.... yes bones. All one has to do is get the fire going with smaller branches before putting in logs or even massive branches that stick WAY OUT.

I took Allens advice and read Ianoto Evans book. AWESOME! It's hard to put down and it gave me some great ideas. You should check it out, I think Piratebay has it too.lol

Thank you for the VERY detailed reply! WOW!

After seeing your reply Im not sure wow well I conveyed my design conceptions. Actually after rereading what I wrote I know I could have done a much better job, sorry:(

1st) Yes, there are 3 different exhaust ports which can all be closed and opened independently from one another. I was planning on having one go through a very large cob bench, another under the kitchen floor, and the last running though cob stairs ( lots of surface area that I dont want to waste).

2nd) From what I understand about combustion, specifically wood combustion, turbulence in the burn chamber should result in a cleaner burn.... Not sure though since I've never built one much less ever seen one! lol

3rd) The feed tube which supplies wood to the burn chamber is surrounded by a 30" barrel, heated by exhaust gasses coming from the riser/double barrel. Kind of a combo 'preheat/dry out your fuel' and 'humidify the air' thing. After all, why burn cold or even room temp logs when a small design altercation can increase efficiency? The reason I want it to give off hot humid air is because it gets so bloody dry in the winter here in Norther New Mexico.

4th) Well I guess thats actually all there is. Do you really think zoned exhaust is a bad idea? Has it been done before?

Hey folks!
I'm experimenting with a few variables for a RSMH, and I would appreciate some feedback por favor.

Sorry if these designs have been discussed already, or maybe they are layed out in a book somewhere. Ok on with the designs.

So first the air inlet is as low as possible to increase the pressure differentiation between it and the top of the riser (which i two barrels tall)
The air inlet is also one of those spinning thingies on top of garages and sheds- I figure it will cause turbidity early in the burn chamber.

Then the exhaust is directed from the heat riser, down the double barrel, and back around the burn chamber for greater insulation once its fired up. Not sure it will make a lick of difference seeing as how high the R value is of the fire brick that is used constructing the burn chamber.

Next is having the wood inlet enclosed by a 30" barrel where exhaust preheats the wood. This seems like an obvious mod that should be done on every RSMH. Again I am sorry for reiterating anything that may have been already discussed/or is common knowledge.
Preheating your fuel (wood in this case) and ridding it of as much moisture as possible will result in higher combustion efficiency right?... That combined with cool dense air should improve it somewhat? IDK, tell me what you think!

I guess preheating the wood also acts like a humidifier, SWEET:)

There are also multiple exhaust outlets for zone control, and 3" ports throughout for shop vac clean out.

Thank you in advance for taking the time to read and hopefully respond!

Eric Markov wrote:

Richard,

You should probably do some tests with the type of wood and rot level you'd use.

Dry unrotted pine logs will only wick water up 2 - 3 inches, probably wick down forever,
never tested it sideways, but would imagine it wouldn't be too far.

Luckily I don't have pine to deal with Pine is more hydrophobic than cotton wood because of the oil content it has, no?....

I am hoping that the flow of water from the main bed, being supplied by that spring or arroyo, will travel down the underground beds. I hope its not too much water for the vines though!