Going Horizontal

I'm re-thinking my RMH build design based on the idea of a horizontal feed tube/ burn tunnel.

It will have to be at least 2' - 3' long horizontal tube/ burn tunnel to reach all the way through the fireplace from the outer wall of existing brick chimney.
I've heard a lot about "batch boxes", but the main feature I like is the horizontal aspect, and the potential for a nice long feed tube.

Any videos or other links that could assist me in this would be appreciated.
Thanks Brett (Damyo505) for the inspiring RMH workshop!
-Peter

Peter Gallo : Welcome to Permies.com, our sister site, Richsoil.com and the Rocket,Wood stove, and Cob Forum Threads. With 28,000+ Fellow Members Worldwide
you can come here 24 / 7 , and find someone who wants to talk about what you want to talk about

As a recent graduate of a RMH workshop you heard some variation of the 1 : 2 : 3 or 1 : 2 : 4 ratio where 1 is the depth of the feed tube, 2 is the Maximum length of the
Burn Tunnel, and 3- 4 depending where your measurements are taken is the minimum~ish Height of the Heat Riser ! ( It can be Taller !)

Regardless of the total length from the back of your fireplaces brick chimney to the base of the Heat riser ( Are you contemplating feeding Your RMH from out doors ?)

There is a maximum distance that you can expect to get a good draft that will continuously support Your RMHs Horizontal burn.

It will be necessary to feed your fire by advancing your wood towards that sweet spot, requiring more time dancing in attendance to your RMHs needs not less ! Also you
will have to be very careful that you do not inadvertently advance enough Burning coals and charcoal to reduce the actual size of your Flamepath, this will definitely reduce
the efficiency of your burn and probably (I Think ) Cause smoke back

If at all possible could you do us a simple sketch of your plan, I simply may have totally miss-understoud your plan ! For the Good of the Craft ! Big AL

Thanks for your kind reply. If possible, could you suggest further research "Batch Box" links that include basic descriptions/ videos of this type of RMH?
I haven't had any luck with my lame searches.

I'll work on some sketches of some proposed designs for you all to poke at.

hi Peter
I just posted a reply on another thread earlier today so some of what i say here is repeating what i said there: I build two vertical feed rocket mass heaters and was not getting enough btus to heat my 34x30' shop so i built a batch rmh and love it. it will take a 36 in. log about 7 in diameter, about 30lbs of wood at a time. This is my 3rd heating season with it. Here's a link to the video i did in March 2013, almost a couple of years ago.

https://www.youtube.com/watch?v=Q2sFParAFEc

I'm glad you enjoyed the RMH class.

Please look at the two examples in the following links: 8" batch box

Innovators batch box. The pictures about 11 posts down help illustrate. It is close to the dimensions you seek.

Yet, notice how tall the heat riser needs to be to maintain the a ratio of around (1:2:4). In the first example it is two barrels tall.

michael Egan wrote:hi Peter
I just posted a reply on another thread earlier today so some of what i say here is repeating what i said there: I build two vertical feed rocket mass heaters and was not getting enough btus to heat my 34x30' shop so i built a batch rmh and love it. it will take a 36 in. log about 7 in diameter, about 30lbs of wood at a time. This is my 3rd heating season with it. Here's a link to the video i did in March 2013, almost a couple of years ago.

https://www.youtube.com/watch?v=Q2sFParAFEc

I like the video... good work, thanks for posting! How tall is your heat riser? Is it 8" diameter? Do you have much mass?

I have a restrictive situation in that I need a long (3ft) horizontal feed tube (or batch box), but I have to stay under 3' for the heat riser. So, from what I've observed so far it wouldn't be a very efficient stove.

If you build a batch box, its length is less relevant to the efficiency and strength of draft. The batch box typically has relatively slow airflow until the gases reach the constricted "port" which connects it to the heat riser, creating a venturi for turbulent mixing and an extremely efficient secondary burn. So if you really need these dimensions, you want a batch box.

Brett Andrzejewski wrote:I'm glad you enjoyed the RMH class.

Please look at the two examples in the following links: 8" batch box

Innovators batch box. The pictures about 11 posts down help illustrate. It is close to the dimensions you seek.

Yet, notice how tall the heat riser needs to be to maintain the a ratio of around (1:2:4). In the first example it is two barrels tall.

I should have mentioned my height restrictions up top. I have a lot of restrictions ... trying to build the barrel half-way in the fireplace ! I've disassembled part of the outer brick/ chimney wall behind the fireplace to create space for a RMH burn tunnel or batch box. Yes, we'll be feeding from "out of doors" but it will eventually be enclosed patio / porch/ mud-room.

I'd like to use 8" diameter stove pipes, if possible for the mass. For sure I'm going to have to develop my own prototype for this idea... but feel free to contribute!

For in-depth development and construction info, see Peter van den Berg's posts at donkey32.proboards.com, and also Matt Walker's. The Reference section has detailed info.

By the way, it is typically stated that a 6" batch box can give heat output generally seen with an 8" system. Matt Walker converted his 8" J-tube system to use a 6" batch box and reports that it works excellently.

Peter gallo wrote:

Brett Andrzejewski wrote:I'm glad you enjoyed the RMH class.

Please look at the two examples in the following links: 8" batch box

Innovators batch box. The pictures about 11 posts down help illustrate. It is close to the dimensions you seek.

Yet, notice how tall the heat riser needs to be to maintain the a ratio of around (1:2:4). In the first example it is two barrels tall.

I should have mentioned my height restrictions up top. I have a lot of restrictions ... trying to build the barrel half-way in the fireplace ! I've disassembled part of the outer brick/ chimney wall behind the fireplace to create space for a RMH burn tunnel or batch box. Yes, we'll be feeding from "out of doors" but it will eventually be enclosed patio / porch/ mud-room.

I'd like to use 8" diameter stove pipes, if possible for the mass. For sure I'm going to have to develop my own prototype for this idea... but feel free to contribute!

http://donkey32.proboards.com/post/13115/thread

Brett Andrzejewski wrote:Yet, notice how tall the heat riser needs to be to maintain the a ratio of around (1:2:4). In the first example it is two barrels tall.

I'm sorry, this isn't correct. The riser of this particular 8" batch box is overly tall and still less than one barrel above the firebox. The riser in this design should be measured from the firebox floor, let's see... that would be something between 34.5" and 43". Since the firebox itself is about 15" tall the riser need to reach to 19.5" above it. If I remember correctly (always busy to convert from metric to imperial and back) a 55 gallon barrel is 35" high so the headroom of the riser would be something like 15". This would be quite sufficient for the requirements of this heater core. Another barrel on top of the first would mean more immediate heat dissipation which was asked for in this particular case.

"Yes, we'll be feeding from "out of doors" but it will eventually be enclosed patio / porch/ mud-room."

If the loading point will not be in your immediate occupation area, that would be another reason to use a batch box instead of a J-tube. You need to see or hear the J-tube regularly to know when to feed it and how it is burning; you can't do that effectively from another room.

Peter van den Berg wrote:
I'm sorry, this isn't correct. The riser of this particular 8" batch box is overly tall and still less than one barrel above the firebox.

Thanks for the correction.

Glenn Herbert wrote:For in-depth development and construction info, see Peter van den Berg's posts at donkey32.proboards.com, and also Matt Walker's. The Reference section has detailed info.

By the way, it is typically stated that a 6" batch box can give heat output generally seen with an 8" system. Matt Walker converted his 8" J-tube system to use a 6" batch box and reports that it works excellently.

OK, does it have to be more than 3' tall riser? Any specific links or helpful vids to research would be good.

http://donkey32.proboards.com/thread/734/peterberg-batch-box-dimensions

The technical info is here, and says that a 6" batch box should have a 43" high riser (measured from the firebox floor). If you make it shorter, you will probably have less power and maybe a less complete burn, but it will probably still work reasonably well. Asking Peter van den Berg directly would be the safest course.

Peter Gallo : I think I get your goal to have all that Fireplace mass be part of your Thermal mass. So there appear to be two very pertinent questions, IF you have
enough height for a barrel ( I was confused, thinking I understood more than one barrel/drum for the heat riser was needed to make the Batch burner work !) And
Second, will you be able to load a batch box from the other side of your Fireplace !

Please send us a few sketches pictures, Your build promises to be very interesting and something to follow on many levels.

A kind of late thought , as your plans are for adding a mud room/ patio on the backside of your fire place you may want to consider the potential for appropriate
thermal mass heat storage /temperature regulation for the season you are in, so that the mass can cool in summer and warm in winter Erica Wisners Comments
in this link probably kinda ought be considered !

Link below !

https://permies.com/t/41595/rocket-stoves/Rocket-mass-heaters-Texas-warm

For the Good of the Craft ! Big AL !