Julien Vailles

Thanks all for your answers, it's much appreciated!.

The design is solid, Wendy in the original website has been using this efficiently, I've asked for her opinion also, but her website forum is probably not actively monitored ...

Couple of answers regarding a few points raised
- Metal mesh will rust, that's why plastic is better
- No pump here, it drains to the green filter using gravity
- The perforated pipe can drain correctly, if I put water on the top, water is flowing, no problem, it proved the pipe position is good, no inlet get in. I have also a mesh covering the top, it has been destroyed.
Having multiple pipes will make the system more resilient, but I'm still not sure where the failure is exactly.
- I have proper drainage stone chipping covering the pipe, I have hole in the pipe under the chipping in case the other holes clogged up, then a plastic mesh, it should prevent this to clog.

The issue is either with
- The holes in the vertical drain riser that clogged up but the bottom one should had helped.
- The mesh itself to small.
And / or the current mix/soup of poo/vermitoilet due to the lack of fast carbon. I think it is the most likely issue to me, I've bought some wood chip, I will restore a better texture and see if the drainage improved. My point, even if with the best drainage, you have a mix that cannot drain because the texture, there is nothing you can do ...

On the 1st of June 2025, see the pic below, it was just after saving the worms as I had the pipe between the IBC tank and green filter clogged up, I fixed it quickly, and then water flushed away really quick, perfect drainage. I struggle to see how come I came from perfect to almost non-existent draining in not even 2 months. I know I repeat myself but I think it is important.



Thanks again!
Julien

Hi Folks,

I built a vermitoilet using http://www.vermicompostingtoilets.net, main schema below



I've started using it (family of 6) early 2023, it has been good so far but 2 days ago, I found out all my worms were dead, the drainage is not working anymore, they were all drown. See picture below



I have 2 IBC tanks, the other one was never used yet. I had a lot of tree branches and large wood pieces for slow carbon release in the active tank, see picture below showing the other passive tank were I moved all the branches from active tank. Initially when I set up my tank, I added a lot of quick release carbon, wood chip, cardboard but it got depleted, and because all the branches, I couldn't mix it up.



I think my system failed as the tank was lacking fast release wood chip to mix up with the rest, without it / carbon, it becomes to thick an blocked the drainage. Slow release carbon is fine but my branches were too long, preventing to mix it with new coarse wood piece.

The interesting bit, is on the 1st of June 2025, so not long ago, I saved all my worms from drowning,  I had a blocked pipe, I fixed it and the water in the IBC tank flushed perfectly! I was really happy not having to dig into it more ... which I am doing now. So between 1st of June 2025 perfect drainage and now total failure, something happened. It was warmer than usual in Ireland, I guess it speed up the process of decomposition and led to this situation.

My plan is to:

1. Add more wood chip, the easiest to get in Ireland, to bring back the tank to a good consistency, good ratio carbon/poo & vermicast.
2. I will cut in small piece now my slow release carbon and may keep only one large for worms in case of, so I can mix the fast release carbon correctly. 
3. I will start using the 2 tanks, I will switch between the 2 tanks every 6 months, something like this.

What do you think?

What do you all think? Any experience?

Thanks a mill,
J

Thanks Gerry! Now I get it, this stratification chamber is super cool and actually fix a few problem! Matt was mentioning a smaller footprint design, I guess it would be to do a vertical stratification bell? Also what about the CSA? is the stratification bell's outlet the same than the feed? Exit chimney, etc.?

As I mentioned a few time I'd like to use it to heat my central heating water.

Main issue with the fire is the burst of temperature. If I was having the coil pipe on the top of the stratification bell or lower if it is too hot, I could have a constant temperature with a max temperature (ideally if I could more the coil pipe, I could set the temp) for it without having to worry about boiling it and going boom!

I've seen this design too before, it's great (because safe) but you still boil water and the

Does anybody here have any exp with this?

Cheers,
Julien

Also I know RMH can heat water (and it is dangerous). As I have already in place a central heating working currently with Aga + oil.
I would ideally like an RMH that could also heat up my central heating. I don't know how good the RMH will heat up the whole house this way.

Hi Thomas,

Yes this is very large, it is inside the house (in the center of the house ish), it looks safe and it was used before with a wood stove, the wood stove was connected to it with only a black pipe and then going like this, very bad job ... So if I clean it, it would be safe to vent especially temperature would be much lower.

I don't fully understand the different of the stratification bell and the bell used for a RMH (when using an airtight metal drum).
I have attached the diagram. Isn't it the same?

Your solution looks great but I think it is out of reach for me, it is my first one I'm building and I'm so DIY yet ... and I've got the book "the rocket mass heater builder's guide" to help.

Cheers,
Julien

Hi Thomas,

Thanks again!

There is no liner on the existing chimney, maybe I've got the wrong terminology, I currently have only a bare large rectangular ~11'' x 27'', pic below showing it.

The flex pipe I linked is in Celsius (Ireland ) - So it's 280F. So it should be good, I'll try to find one better if possible.
 
I'll search for a "common single-wall black stove pipe", I don't know. To give you some context, I'm French living in Ireland and many things are not available here, a lot is imported from the UK or used to be with this Brexit.

I never heard of "stratification bells" - I tried to search on the forum, no luck.
But not needing a mass and pipe would be great, my wife is not too happy about the space required by the RMH mainly because the current setup of the room, we will have to make a good few changes to fit it!

I've attached a pic of the room I'm planning to install the RMH, on the left there is the door and on the right there is some storage. Behind the old stove I have an oil aga.
I was considering knocking the storage space (it was an old door replaced by storage, on the bottom there is some pipes to I'll prob cut only half of it) for air circulation but again my wife doesn't like too much the idea!

Cheers,
Julien

Thanks a mill for your answers Thomas, very useful to me!

It will be a J tube in fire bricks so I should go with rock wool - mineral wool.

HVAC pipe is a ventilation type pipe, right? No regulation here.

I found this for the exit chimney flue, I need a flexible one as there is at least one bend and I don't know what else, it can support -30/+150 degree, I think it should the job  flexi item - What do you think?

I found those pipes for the mass heaters, metal pipe - What do you think? They have T pipes and 90 all in 200mm, it is not super cheap but so far I couldn't find better.

Cheers,
Julien

Hi Folks,

I'm working to design my first RMH for my 2 story stone house (2 floors, ~100 sqm) in Ireland.

I don't have a definite design yet, I'm still going through books, see what's available here in Ireland/UK, etc.

1. Based on my house size, I would go for an 8'' CSA
2. I have no liner in my current exit chimney, would a flexible flue liner be good enough? I know the temp is not supposed to be high if you have a decent mass heater size. I still don't have the exact size, something like ~5m x 1m (length of the wall in a L shape). I'll put a diagram soon.
I was thinking something like this ebay flue liner even if it more expensive than I thought and I think the stainless 904 is overkill, 316 is good enough. It's not available on my hardware shop, nothing in Ireland ... !
3. For the mass heater, what do you use? Is it something like this? Example mass heater pipe
4. I still need to read more but one difficult point for newbie like me is to find what material to get, like the one to insulate the raise heater (I've already bought my drum, my firebrick (124 total, prob too many but I'll prob too another rocket stove later on). For the mass heater filling, I was planning to use concrete and stone, I got many from my various DIY job + Cob for the inside. Would normal Cob be safe for the inside? Or do you need fire clay for the mix? Things like that is very tricky especially when your hardware shops have no clue about this stuff.
5. As my wall is in stone (it is not bare stone, there is a layer of something, prob cement), it should also be warm up if I have the mass heater close to it, touching it?

Thanks for your help, I'll post more details when I'm progressing my design.

All the best,
Julien

Coydon Wallham wrote:

Julien Vailles wrote:
Like I've found out about the 4'' exit chimney I had in place for my wood stove and I am quite sure it is too small (in this thread, they were saying 6'' is already too small, we should use 8'') and I can't use bigger in my design because the cross-sectional area ...  or can I?

I think that person was exaggerating or over generalizing. At last fall's rocket mass heater jamboree, Paul and uncle mud concluded from various experiments over the years that 4" RMHs don't end up working efficiently. There are numerous examples of 6" systems that work very well. They are now considered the smallest worth building though. Your 4" exhaust would restrict a 6" system and prevent it from performing well.

Thanks a mill Coydon! It confirms my thinking, I'll see if I can replace it with a 8'' (reason being is I've got a ~100sqm 2 floors stone house so I need some output), if not I'll switch for a 7'' (I don't know if it is available) or 6'' ..
I'm planning to create a new thread to get my design validated by the community!

Cheers,
Julien

In Europe and Ireland in my case, nobody really know about this, I came across to it because my interest for permaculture.
I've started to learn how to build one, read a book and now working on a design but this is not simple when it's the first time you do this.
It would be good to have access to experts (for the design) from different part of the world willing to help for free or a fair price, the forum here is great but you still have to do a lot of researches before asking pertinent questions. Also finding the correct material is not easy when you're not doing DIY for 20 years.

Like I've found out about the 4'' exit chimney I had in place for my wood stove and I am quite sure it is too small (in this thread, they were saying 6'' is already too small, we should use 8'') and I can't use bigger in my design because the cross-sectional area ...  or can I?

I'm already promoting the idea but I need to do it first then people will see how good it is!