Mark Roelofs

Hi Glenn, welcome to the thread

Thanks for your suggestion. Half barrel also is/was an option. I do have quite some barrels laying around here. I'm just a bit vague on how the practical build would go regarding some aspect. I have been searching for build video/threads, but havent found any really. If anybody know of any, I would appreciate a link. I have some general questions If I would use barrels..

- Because of the shape of my bench, I would have to do a L shaped half barrel chamber. Matt Walker mentioned in his video that for the 90 degree turn, he just loosly cut some holes in the barrels and pasted them together with cob. Would cob be a proper way of sealing everything? Because cutting holes in barrels might not get me a tight fit like bought ducts would.

- Half a barrel is 30cm heigh. I would like to have a bench of ~50cm heigth. If seeling with cob works well, i'm thinking of just lifting the barrels of the ground with a layer of stones and then cob to press the bells into. this would make the chamber heigher, and reduce the amount of cob needed on top of the bell. I read in a different thread that 2" / ~5cm of cob on top of the barrel might already be enough.  

- Would the idea of putting the input duct from the manifold into the chamber work with a 90degree angle? I would prefer to push the hot air into the main part (the longest part of the L shape) of the chamber. Like in this video:

- In my setup an 'juice box' exit pipe would work well, i'm just not sure if I could locate it nicely against the wall. Put there might be room in the corner to just put a 90degree bend upwards.

I think I will make a quick sketch to see how this all would work in my setup. Half barrel would save me a bunch of money, and help with using the barrels I have laying around. And since I have not started on taking out the old chimney, there is still time for endless design changes haha.

EDIT: IF i do a half barrel, i will try to document the build here with a lot of photos. Although I have to say i'm very good at forgetting to take fotos of project/work when i'm busy with it...

Maybe to be more clear in about the post above. The size of the mass bench is more or less the same with 5 or 6 meters of tube. I just want to get the most heat out.

I have been searching/finding (well, actually the dogs dug a whole in a hill and found it) some clay and im making some test blocks. Very interested in working with clay, all around my house cement is crumbling with the years and it is poluting the land. Clay would be a way better option it seems.

I have made 2 bricks of half sifted (2mm) clay and half sand. 1 brick of only clay which i took out the bigger stones, and 1 brick of half clay which i took out the bigger stones and half fine sand. Let's see how they dry up. The clay balls I made before have all dried up nicely, so this is definilty useable material.

For the bulk of the mass I don't think it will be needed to have very fine clay/cob. So i will just make a filter with some chicken wire to get the bigger stones out. And then for the final plaster or for making clay slip I will sift some clay.

Probably will also make some clay seed balls this autumn to put out some different plants in my forest.

I plant favas in late october and let them overwinter in the sunny spot of my garden. My plan is to have a crop of beans before the summer fruits go in. I have 2nd generation seed now, i hope they get a bit more winter hardy with the years. I bought the most cold resistant once, the store bought, first generation, had a lot of loses i  the winter eventhough the weather was pretty ok. This year, the 2nd generation, survived way better with more extreme winter weather.

I also have fava beans that i bought as chicken feed, i will use these in the fall this year to grow a covercrop in my perrenial potatoe plot. That spot has no sun in winter, so they will most likely winter kill. But they will still have some months of growing season.

Hi Benjamin,

Yes i did, but that would give me only 5 meters of tube, that seems like a very small system.

Hello, i'm back. Took a small break from this project for other projects and to read the Wisner book.

I have stepped away from the 'complex' design i was thinking about and will be going back to the classic: pipe in massed bench. This seems more foolproof, simpler, and I have almost all materials laying around here so also cheaper. I have sketched 2 remaining options.

1: just a simple corner bench. This has 6 meters of pipe in it. About 2500 kgs. I have put the firebox and bell close to the kitchen opening to also get some warmth in there. The idea is also that the bell and chimney will radiate onto the kitchen wall and heat that a bit. The connection of the bench to both walls will be insulated in this setup.

2: The bench has a masonry backrest attached to the kitchen wall, the upper part will not be insulated so that some heat will reach the kitchen wall. This has ~7meters of pipe in it, weighs about 2900kgs. It does has more bends, and no 'kiss the barrel'. But in this case i would add a T to have a prime option if it would be needed. For the total pipe lenght and number of bells we are getting closer to the maximum, but i think with the nice straight up chimney inside the house and the prime option it should be fine.

For the firebox and manifold/barrel I will just use the Wisner's book design.

I think both setups will work fine, so i'm not sure yet what my criteria is going to be to do either one or the other haha. The idea for setup 2 is mostly because setup 1 only has 6 meter (20feet) of tube, and that is on low side.

Maybe better used to start the chimey/fire..? The 8% probably burns nicely

Im using all the oak bark i have as mulch underneath my fruit trees. With time i will move to living mulch (plants). And i think i will just relocate the bark to other trees if it is not needed anymore. I do not grind it down, the big chuncks will last many years as mulch here.

Both  trees are in the sun almost the entire day. They only miss some morning sunshine

We have 2 mature Tilia trees in front of our house. They were already there when we bought the place 2 years ago. I live in South of Spain, but I live at 1600m altityde on the north side of the mountain. So i do not have the typical mediteranean climate. We have a bit more rain then at lower altitudes and freezing temperatures in winter. Summer are still hot and dry (maybe one day of rain per month).

The trees are doing fine and are healthy, my wife likes to collect the flowers for tea.

It is not about saving livingroom space or money in bricks. It is to heat the kitchen via the wall that is already there. Making a continiuous bell, with a 1cm gap between the bell wall and the kitchen wall will ofcourse also heat the kitchen wall, but to much much lesser extent (i think). In the end the kitchen wall will become warm of course, but will it be enough to really warm the entire kitchen, and maybe even the bed and bath-room..... ?

I also do not want to tear everything down after a few years because it does not work. That is why i'm gathering ideas and opinions of people with experience. If everybody hear says, it will probably not work, I will change my design. I prefer to first make a proper working heater, and then maybe experiment with something later, instead of the other way around

The floor is thick concrete, everything in this house is build pretty massive as you mentioned. So the weigth of the bell will not be a problem