Batch boxes and horizontal runs

Hello everyone.

The time is coming near for us to finish the rest of our home going from 750 to 1500sq.ft. Currently we have a wood stove that I surrounded with rocks and cob. Putting the mass around it cut our wood consumption in half (about a cord now.) So when we finish the home the area the heater will be is centered in the house and from floor to top of roof is 17 feet so the exhaust will go up to 18-20ft so I should have great draft for a rocket mass heater. But I don't want the conventional, some kind of batch box is what we want so we don't have to tend it so much. How is everyone getting their box? I've seen some made of concrete (ish) material built on site and I've seen some metal box styles. I'd like to have a glass door so any links to sites to buy them would be great.

I've got a blank space to build on a L shaped wall (probably 12x12 maybe 16x12) so for the exhaust being 18-20ft in the air how far can I run horizontally and how many 45 or 90's can I do? I know there is a formula but I forget it. I'd love to see everyone's stoves and some thoughts on and ideas.

Thanks in advance!

Josh, don't use Metal for a Batch box. Refractory is the only way. Better even, insulative refractory.

Pipes, i think hinder the nature of the beast. It has, and can be done. But not on many builds.

At least use Matthewwalker's half barrel system of bells. Or a real bell.

Questions to ask yourself, do you want seating? Or just radiant heat? Do you want a monolithic piece, or something taking more floor space and less height? The glass door is no isue whatsoever.

Josh Hatton: While I truly expect to be reluctantly dragged forward and eventually adopting the Horizontally loaded, batch fired RMH I am not there yet !

I won't try to answer specific questions on that point .

Location, Location, Location! Without an Idea of your heating season (Your present Elevation my be the single most important feature) We will be guessing

at the correct size for your Rocket Mass Heater RMH.

Bringing your Final Vertical Chimney up through the interior of the house is generally preferable. When the Final Vertical Chimney is on the outside of Your

Home it is then much more important that it be located on the lee or downwind side of the house! In any case 20' sounds like the bare minimum height for

the top of your chimney to ensure at least 3-4 feet over the peak of your roof !

If I am understanding you correctly you are expecting to have a cathedral roof or at least an open 2nd floor area with a ceiling height of 17'-18', A large

portion of your heat will raise by convection to that height and stagnate.

This has been preferred practice where a Loft type sleeping space is planed. This Ceiling level hot trapped air makes sense when one allows the wood stove

Fires to ether ''go out' overnight -Or chokes down the wood stoves fire to '' hold coals overnight '' - with a Rocket mass heater more of the heat will be

retained overnight in the Thermal Mass, Expect changes to temperature at your 2nd floor ceiling, if necessary a simple fan and some ductwork can pull that

hot air down from your 2nd floor ceiling into the core of your home ! A simple timer can assist getting the heat where you want it when you want it!


Please take anything that you see on U-tube with a small mountain of salt, there are huge boatloads of steaming stinking Crap videos to be found on U-tube !

Do not even consider any thing that uses Metal in the Combustion Core -also any use of Portland cement near that core is also doomed to failure and a complete

re-build !

Just like all wood stoves out there you will need to accept that any type glass installed allowing a''View of the Fire'' will be affected by the fire and will have a

slight negative effect on the burn temperatures and your RMHs Efficiencies !

In clearer English there will be deposits of smoke and other materials onto the glass- You will still see the flames but generally your glass will be stubbornly

Translucent to firelight and not Transparent !

People who have accepted this fact have successfully used glass pie plates or the glass shelves found in Microwaves, or even toaster oven doors to enhance

their viewing pleasure !

O.K. Generally speaking while the Batch Box RMH may not be as cleanly efficient -many reports state the Horizontal Chimney distances are comparable !

A 6'' system should allow a Horizontal Chimney through the Thermal Mass for 30 feet ! - Minus 5 Feet for every Elbow or 'T'

An 8''System should allow a Horizontal Chimney through the Thermal Mass of 50 feet ! - Minus 5 feet for every Elbow or 'T'

This is where I recommend going to Rocketstoves.com to download your PDF Copy of the Brand new 3rd edition of Ianto Evans' "" Rocket Mass Heaters''

This is " The Book'' which will walk you through figuring the needed Constant cross-sectional areas CC-SAs and save you time, materials, money, and

frustration on your 1st build.It will be an important addition to your library and the 1st book you lend out to close Friends .



This is where I sit back and watch for the comments of your other Fellow Members who are Rocketeers . For the good of the Crafts Big AL.

I know all about installing wood stoves properly and was a home builder for awhile and built this home also. My ceilings are flat, 10ft on the inside with 4/12 gable roof with the stove pipe coming out dead center of the house (right at the peak.) So it will probably be 19-20' from floor to top of stove pipe (considering pipe will be at least 4' above roof.) Up to 10' will be inside, up to to 6' will be through attic space (triple wall pipe) and 4' or more above the roof (triple wall also.) The perfect set up for a good draft. I also plan on building an 8" system.

Since I've got sooooo much height inside it would be best to go up but the wife likes the idea of something to sit on....but the layout might not work out right to have seating. Mostly I want to heat my home with little wood and more even temps which our current stove does but just not as good as RMH. Satamax can you add a couple links with images of the bells you speak of? I've found them on Google in the past but would like to see finished and the interior design also.

I'm in Kentucky, Northern, so I get some cold weather. It can be in the 10's (all temps in Farenheit) for a month and below zero at night for the same period and sometimes hanging around zero for a high for a week or so.

The only reason I want glass is to get an idea of what is going on with the fire without opening the door. Has nothing to do with 'looks' or 'romantic' stuff and I've had glass doors on stoves before I know they get gunked up (spent my whole life with wood stoves.)

I've read the Rocket Mass Heaters book but I'm more interested in folks that have built successful batch boxes stoves (including masonry heaters!!!) I've actually built and been around RMH's that the feed tube goes down but that's too much tending so I'm looking for less tending in mine with longer burn times

Thanks for the replies!!

Josh : You might like this masonry D.I.Y. Build ! see link below !


https://permies.com/t/12828/wood-burning-stoves/Homemade-mass-heater

For the crafts ! Big AL

Here's a few example of batch with bells.

http://batchrocket.hostoi.com/html/foto.html

http://technologieforum.forumatic.com/viewtopic.php?f=19&t=27



I quite like the following bell wall idea. With a J tube. But could be built with a batch too.

http://heatkit.com/research/2009/lopez-rocket.htm

Adiel and Shilo have done extensive research on thoses batch rockets, even with side risers.





I realy like Radek's big two storey build too

http://donkey32.proboards.com/post/15600/thread

I realy like hendrik's latest build too

http://donkey32.proboards.com/thread/1556/why-side-window-door?page=2#scrollTo=16159

http://www.ecologieforum.eu/viewtopic.php?f=3&t=4610

No i'll delve into Matthew's latest build.

Which is not pure batch rocket with a heat- riser.

http://donkey32.proboards.com/thread/1624/walker-riser-less-core

Here's one half barrel and batch, being built at this moment.

http://donkey32.proboards.com/thread/1903/rocks-mud-inch-batchbox-greenhouse

Hope all of this inspires you.

Thanks for all the links and info. All this stuff should help me design a nice stove to heat the house with little wood.

Thanks again!!

Josh, as you will note in some pictures, it is also possible to build a vertical bell RMH with a bench added (effectively a double bell, the bench being the second). You can have enough length to stretch out on and enjoy without taking up too much floor space.

So instead of going up with the bell you lay it down? I've seen pictures of a nice build the was a bench with chamber instead of pipes. Could I start with a bench (bell) and end with a vertical bell? That would be the best layout.

Josh Hatton wrote:So instead of going up with the bell you lay it down? I've seen pictures of a nice build the was a bench with chamber instead of pipes. Could I start with a bench (bell) and end with a vertical bell? That would be the best layout.

You need something highish to house the heat riser so, your construction can't be done. Except using Matt Walker's new riserless core. Myself, i would go brick tower to house the heat riser. Then the bench. And may be a metallic radiator at the end.

Just to emphasis my previous reply.

http://technologieforum.forumatic.com/viewtopic.php?f=19&t=27

The pictures are prety much self explanatory. You can use a bench bell. But only after a tall bell, as it has to house the heat riser. Mind you. You can use a barrel too. But in my recent build. I discovered that i would like a first bell of massonry. As it doesn't release verry high heat at first, and the high heat inside charges the mass better. Due to a greater temperature differential. And the latest bell in line, to be a metal radiator, as the heat released is gentler. So you don't overheat the place before the mass is charged.

Well, you don't need as big as the previous one. Something like this over a 6 inch heat rised could well do.

Ok here's a picture of what I'm planning, rough layout. I've got plenty of room (up to 10') to go up with a heat riser so I can make it however tall it needs to be. And the length can be somewhere between 12-16' on the one wall and 10-12' on the other wall. I've added a quick drawing of that as well.

That looks like it should work quite nicely. What is the structure of the 12-16' wall? If it were masonry, you would have an excellent means to heat the rooms on both sides by using the wall as thermal mass. If you can replace some of it with masonry while keeping heat away from wood, you could get some good effect. What are the uses of the different rooms?


Oh, and what is the floor structure? Is there a basement? What are your plans for supporting the mass? A bell is a more concentrated load than a bench, and does require a real foundation, where a bench can sometimes get away with just a bit of beefed-up support.

It's a slab (actually monolithic foundation) so it can handle the weight. The wall will be open above to allow heat to move between living room and kitchen area. The house will be 3 need, 2 bath.

Cool, not built yet, so you can make parts just how they need to be without retrofitting or adapting