Fox James

Rico, yes I have lots of YouTube videos and my designs are also documented on this forum, I don’t like to keep re posting the videos but you can find them on my channel https://youtu.be/LbZTkuiMBRU

Hi Rocky, batchbox stoves are more complex than a J tube, they would generally require, accurate air control and a door, this makes them more time consuming and more expensive to build.
Many folk prefer the bigger load and the more powerful results that a batch box can offer. however you can still use them with half a load if you don’t need too much heat.
On that basis I don’t think anybody has ever asked your question before.

You can often find people comparing a 6” batchbox with an 8” J tube in the power stakes but they still work in a slightly different way.
Personly i have both designs in use in different locasions . I prefer a J tube with a hotplate for cooking and a batch design for mass heating.
Good luck with your revision, keep it up and you will discover the best option for your personal use.

Well it is a small world, I bet you are glad you left that horrible place…should have moved to Guernsey   ha ha!

We have rocket mass heaters and there are rocket stoves without the mass.
Therefore we could have a compromise between the two.

A six inch J tube can be built from lighter materials like vermiculite board or insulating fire brick but it is the mass that can cause the structural issues.
If you want long overnight heating from a pre heated dense mass then there are not many compromises but if you want fast radiant heat then you just need the rocket engine.

I have my own version J tube with a small amount of mass that works perfectly for my circumstances, it has glass viewing windows a short burn tunnel and a spinning vortex riser.
I also use an extremely efficient vortex stove with no mass at all but it looks amazing and throws out heat like you would never believe but has zero mass!
Peters latest Shorty core is relatively easy to build and is much more forgiving about re loading to produce radiants heat all day long.
A lot depends on how well your house is insulated and how much wood you have to burn?

Building a prototype in your barn is a great idea, it will really help you understand how everything works and the performance that can be achieved.
Rocket stoves are not always as impressive as people expect, you have to be realistic when sizing and building to find a compromise with the overall size, the amount of work and expense involved.
Building a mock up, possibly using dry laid fire bricks will help you no end.
Also there are other options that might help you build a lightweight stove with less mass, maybe not exactly what you planed but still a super efficient stove that can be placed in you home without massive foundation work.

If you want a hot spot on your barrel top for heating a pan or kettle then stick to 2.5”. Otherwise make it more.
Some designs use two barrels on top of each other for space heating, meaning you could have a top gap of 48” if you wanted to!

Well a standard 6” J tube will required feeding  with fuel every 20-30 minutes so do you have a plan for that aspect?

I think Tom has it right, it may be possible to run a smaller than sytem size chimney but it might not work as well as the original design.
It might also depend on how concerned you are about air pollution as a smaller chimney might appear to be operating just fine but in fact it is not.
However, there are definitely some folk using 6” chimneys on 8” system size.

Hi Fred, no as Ben points out the barrel (s) can last for years, it is the  secondary air supply feed that will degrade!

Personally I love J tubes, they are very simple to build and use, one  disadvantage is the need to keep topping up the fire box with fuel.

I have my own design J tube that has a glass door and a viewing window, it also only requires a fairly short riser that easily fits inside a single barrel.
If I were you I would spend a few days looking at the builds folk have completed on this forum, there are quite a few choices.
A lot might depend on your DIY skills or your budget.

Here you go Mr Pink….

Hi Fred, exciting times for you then.
The old style batchbox is a powerful stove but it has a few restrictive aspects from my perspective.
The riser it’s self, is what makes the stove work so well but, it is a tall component and you would need more than one barrel to enclose it.
Another issue for some people might be the internal metal work that will deteriorate quite quickly although Tom (who made the above post) can sell you a few components that will help your build……
There are more up to date models that don’t use a full size riser but rely on a good, ideally straight up, tall chimney.

I don’t think the riser less stoves are quite as powerful but, they might offer more options to make them fit into your home.
One of the benefits from my prospective with Peter’s latest design, called the ‘shorty’ is you can re load the fire any time you like without causing any problems with smoke or reducing the stove clean burning aspect.