Mark Roelofs

Day 4/5 update: Grinding away on the chimney. It goes OK, but I have ran out of cutting discs and because my grinder is very old, all the stores here do not carry 18cm discs anymore. So ordered some from amazon. So this work is halted for now, Really do not understand why you would make a chimney like this out of 10mm(!!!) thick steel. The bottom plate would make sense, and the baffle as well. But everything is 10mm thick. No way is that needed, especially with the low temps you get in a fireplace like this....ah well, build to last i guess.

I still have some other prep work to do: Cleaning up barrels, digging more clay, figuring out how to seel the manifold and the top barrel, etc.

EDIT: Day 6: Found some more grinding discs so managed to get another piece out. Also started welding in new supports for the big  steel chimney. I will take a big part of the bottom of the chimney off, to have more space to fit the exhaust of the RHM.

EDIT: Day 7: We continue

EDIT: Day 8: The chimney is gone and I have welded all the supports onto the remaining piece of pipe. Now just to remove a part of the pipe at the bottom and then remove some more cement and stones to make the floor a bit more level. And then cleaning up...

EDIT: Day 9: I guess the first phase of the project has come to an end!

I was searching for random homesteading topics and was fed up with generic google answers. So for every search i started putting 'forum' in the search, then i ended up here a couple of different times. I think around the same time I was also getting some Paul Wheaton shorts on youtube. And since many things he was talking about made sense (I think it was mostly RMH, because I was looking into that as well) I was watching him more on youtube. Later I realised that the forum google was sending me to was actually made by Paul.

Progress of day 1 of deconstruction.

EDIT: adding day 2 pictures.

EDIT: adding day 3 pictures. Now we have the chimney leftover to do. I do not know why, but it is 10mm thick steel.....it will cost me a lot of angle grinder discs to cut it into pieces and get it out. We might keep a part of the super thick steel chimney, might look cool when it is nicely painted. The RHM output chimney can always be put in it.

Nice!

I have planted a number of plants last year as well, but they all died (or so i thought). They came back quite early and are also starting to flower now.

Thanks!

We have many chimneys... On the roof, the one on the left is for the RMH. It is maybe 1 meter of stone and then 3 meter of black pipe.
On the roof, the one on the right is for our kitchen stove, it is only stone. Draft is a lot worse with that one, the kitchen stove needs careful lighting..

Then the one closest to the RMH is the chimney from the downstairs (future) workshop. Also part stone and pipe

And the stainless steel one is fromnour diesel central heating.

Maybe one day i will make another one at the back of the house so we can geat with wood there too. Never can have enough chimneys

We have a manifold and barrel. There is about ~12cm of space in between the barrel top inside and the heat riser. I think I miscalculated one brick thickness, because i was aiming for 8cm. In the end, that would have made my manifold even lower, it is already pretty close to the top of the burn tunnel. I have nice clamps to connect the barrel to the manifold, but there is only 8cm from top of the burn tunnel to those clamps. So for insulation and a cob layer... I might end up having to (partially) cob over the band clamp. Ah well, we'll see.

oh, I thought I read in the manual that rockwool would be ok. Well, superwool will be better! Rockwool around the woodfeed and burn tunnel will be fine no? Temperatures will be way lower there.

I see I haven't shared the latest (dare I say final) design. It will be half barrels, with the exit pipe (150mm) put in about half the way into the stratification chamber. I will make a 10cm heigh wall below the half barrels (the barrels will sit on top of the wall to increase the heigh of the stratification chamber) and fill that in with floor insulation of about 5cms. On top of the barrels the bench will be made with cob, to a height of about 50cm.

The exit pipe will have a T in it so that we can prime the pipe if needed. Sometimes in winter we are away for a long weekend, so I think it will be good to have a primer.

Insulation of the floor and walls will be done with expanded clay. 10cm underneath the core, and 5 cms for the chamber and walls.

@Fox James: Thank you for that thread, that basically answered all my questions

Yesterday evening I dry-stacked the core and did a test run. Went well I think, the fire was very rockety and the heat out of the chimney was intens. Very exciting to see the power of the core.

For this 8" system I ended up with the following dimensions:
Woodfeed: 20x20cm opening, 41cm height
Burn tunnel: 20x19cm (WxH), 60 cm long, roof of 20cm
Heat riser: 20x20cm opening, 119cm height.

I made the heat riser out of 4cm thick firebricks because i bought a second hand batch and have too many anyway. I plan on insulating with rockwool, which i have laying around. The heatriser I was thinking of 6,5cm thick, and the woodfeed/burntunnel with a double layer of 4cm thick. And then finish it with cob.

Next step will be to cut the half barrels and clean them a bit more. I'm also gathering some materials and soon i will start with tearing down the old chimney to make room for the RHM.

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...