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podcast 414 - The problem with batch box rocket mass heaters - Part 2

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Location: Kingston, Canada (USDA zone 5a)
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Credit: Eric Tolbert

Part 2 of the podcast picks up with Erica pointing out that most people learn only one way of starting a fire and use that for every fire they start. There are actually multiple different ways to lay and start a fire. Erica's mother used to say "If you light the fire, it's your fire - you are responsible for messing with it". Ernie points out that "Gilligans" have been taught to start a fire by their parents and grandparents in a way that worked for their stoves and their situations.

Paul moves on and shares his fire starting technique. Paul and Jocelyn accumulate burnable items all year long to start fires with and by the time the season for heating rolls around Paul has a large backlog of paper products. In an attempt to use up his backlog Paul puts approximately 12 pounds of paper in the back of the burn tunnel and then prepares with regular sticks to be used after his ridiculous amount of paper is started with his propane torch. Paul then puts in the sticks and sprinkles the fire with magic Fairy dust (wood shavings from making kindling) to get the fire going well.

The discussion then turns to the main topic. Paul and Ernie believe that a "J-Tube" system burns less wood than a batch box heater and Donkey disagrees. Batch boxes are designed to be capable of burning more wood at one time than a J-Tube system and Donkey believes that if you balance the mass with the firebox and only load the batch box once you will get more efficient burn and transfer to the mass. Erica points out that both freight trains and a Prius are both efficient in different ways for different purposes. All the builders do agree that if you are novice that it would be best to build a J-Tube or several outdoors before you attempt to build a batch box heater.

Paul is still of the opinion, even after much discussion, that batch box heaters are still inferior to J-Tube style and making it difficult to move Rocket Mass Heaters forward. Donkey disagrees with that assessment and points out that many Masonry stove builders in Europe are doing fantastic work. It's pointed out that Batch Boxes are not a novice toy and really should be attempted by more advanced builders. Donkey also points out that in the early days of the Rocket Mass Heater it was possible to make modifications to the basic design but after fifteen years of experimentation and building there is not as much room currently for improvement over the basic design.

Erica points out that the fact the mass in an RMH is still putting out heat when the stove is not burning which is way more efficient than any other stove currently working. The fact that you can heat your home with 1/10th the wood is too fantastic for most people to believe so there is discussion that the concept might be better accepted if it was claimed that they only use 1/2 the wood, even though they are way more efficient than that. Ernie says that he and Erica pad the amount of wood that they use to be more conservative so that people will believe them more readily.

Ernie points out the discussion with the people currently in the room around both J-Tube style and Batch Box heaters  is really just about quibbles until you introduce the Gilligan Factor. Donkey points out that J-Tube Rocket Mass Heaters are designed to be built in a lower price range with lower quality materials and the Batch Box are branching back into a more professional stove build with a much higher price point.

Donkey and Ernie, both instrumental in developing the RMH technology, ramp up a mini-rant about how they have created the instructions and put them out into the universe and the inability of people to actually follow the instructions in order to create successful builds. Erica ends on a high note with "a bad workman blames the tool when things don’t go right and blame failure on bad luck, a good workman attributes success to good tools and planning".

The takeaway overall is don't build a batch box for your first build and make sure your first J-Tube builds are done outside until you have the concept and skills down before attempting to move them inside.

Relevant Threads

The Gilligan Factor
Wheaton Labs
WOFATI (Woodland Oehler Freaky-Cheap Annual Thermalized Inertia)
Natural Building Project
Batch Box Rocket Mass Heaters
Donkey Forum

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Posts: 2169
Location: Massachusetts, 5a, flat 4 acres; 40" year-round fairly even
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Oh my God you four are hilarious!
Joshua Myrvaagnes
Posts: 2169
Location: Massachusetts, 5a, flat 4 acres; 40" year-round fairly even
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OK, now I"m convinced again not to try to build a batch box, the J-tube seems to be about as easy to use all things added up.

I just want the Cyclone exterior!   can that work with a J-tube out the side???
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