typical temperatures inside rocket mass heater

Hello,

i am working on my first RMH and am wondering about the temperatures inside.

I found information that temperatures inside the core can go up to 1000*C. But what about other parts of the heater ?
- what is typical max temperature at the top of the primary bell ?
- what is typical max temperature at the bottom of the primary bell (floor) ?
- what is typical max temperature at the top/bottom of secondary bell (bench) ?
- i found information that chimney temperature will usually go between 60-100*C

the reason i am asking is so i can better choose the materials:
- to isolate the floor. the heater will be build in the room with concrete floor, i don't want the heat escaping into it, so i want to build a proper insulation layer below the heater.  I saw how perlite can be used but i am worried about building on top of loose perlite so i would prefer to use something load bearing. I was thinking about using YTONG blocks covered by a layer of concrete made out of cement and perlite.
- to isolate the back wall of the heater and bench which is going to be build against the wall stone of the room. I was thinking about double skin bricks with a layer of ceramic wool in between them. I don't like it so much as there is still one layer of bricks absorbing the heat there. I was thining about using ytong blocks instead of bricks for the back wall of the bench, still doing double skin with ceramic wool in between. ytong blocks are ok up to 600*C, so i want to be sure temperatures inside my bench are not going to reach that level. I am wondering if i could do the same for the back wall of the primary bell ?

any other suggestions on how to insulate the floor and back wall ?

thank you.

Hi Peter, you don't mention what type or style of rocket stove you would like build?
Something like an 8” batchbox  is going to be a different animal to a 4” J tube, there would be  a massive difference in temperatures!
I doubt if many of us know what a Ytong block is but anywhere in the flame path you want materials that can stand at least 800c but better to use 1200 rated materials.
So we would need more info on your plans?

ytong blocks are aerated autoclaved concrete
i am building 8" batch box

Hi Peter;
With an 8" batch box you're looking at closer to 1100C  in the riser.
After leaving the riser things start cooling rapidly.
The top of the bell directly over the riser will be getting a direct shot of high temp air, I would guess that it could still be as hot as 900C when it hits your bell top.
The bottom of a bell should be near 65-85C but could at times be over 100C.
If you are building a bell rather than a piped mass then no need to extra insulate the concrete slab,  falling fly ash will cover the floor and become an excellent insulator.  
If you want extra insulation then you mix powdered clay and perlite with straw into a cob-like product.
Loose perlite alone is used to insulate between walls or between your mass and an outside wall.
A ceramic blanket is an alternative wall insulator, but much more costly than a sack of perlite.

Hi all


This is old thread but give some new live now.


I want to build a rocket mass heater or a batch version, for the last one I have a nice door.

I want to get the heat from it through a coil where water come in and the output go to two radiators of 2500 watt each.

Possible I connect some more but for now I do this, now the question, I want te be safe, the protections I do now all
about and the system pumps after warm up continuously through that radiators I use a expansion barrel and over pressure valve.

To put the coil in, I do now now for shure what is the best place, I think lower on the barrel or using a isolated chimney part
remove isolation and put a copper coil in it and isolate again on the outside as far as this is possible, or put coil a bigger
and less winded one in the barrel itself, where the temp is high enough for that power and do not cool the part where hot
is needed for his afterburn so not on the top of the barrel who also wll cause possible dangerous situations because to much heat.

or make a barrel of stones, and set a coil there on the bottom or outlet pipe just after it come out of the stove and tap heat there.

Maybe someone now a idea, making a box with pipes is not a option, to dificult and a lot of welding needed.

Build a Batchbox with a double-skin bell.
Place the coils between the inner and outer skin.
It will be above boiling, but not near the super hot riser temps that can flash to steam.

thomas rubino wrote:Build a Batchbox with a double-skin bell.
Place the coils between the inner and outer skin.
It will be above boiling, but not near the super hot riser temps that can flash to steam.

Tom has a good point here, and I would like to elaborate a bit more.

1) The facts and figures are out there to size and make the perfect bell sized for X size of batch box.   Lets say a 6"  So everything we need to know to build this right is out there.  And this bell will be system tight ( no smoke or exhaust escapes)  with proper flue operation to boot.  What I am getting at here is that the engine is going to work right no matter how you could screw up your "hot water part"

2) Between the inner and outer bells- you have the area and opportunity to lay your flat coils against the bell sides.  With calculations, you can get the water flow, btu extraction and the like but your gonna have experimentation for sure.  But again, the main engine should work correctly. ( very important)

3) with the double bell, you can route your inlet and outlet lines how ever you like without the concern of expansion joints for these pipes having to hold exhaust escapes. Again allowing your main engine to work top notch.

4) the second bell can easily be laid up with the clay/sand mortar in case of a redo someday.

5) Remember, boilers are set up for constant heat to the water, you won't have that, but you will have a harvestable heat, between the bells. It just may not be as predictable.

6)  Pop offs can be put really close to the heat source, they may never go off, but you will be glad you have them if they do.

I can absolutely guarantee from personal experience, that if you try to pull heat from right at the exit flue area of your rocket stove, you will not be happy.  But for quick math,  lets say you have about 100 degrees exiting on start up for the first few minutes  and you try to pull this down to say 80, but instead pull even more, things won't work well.  And later one, it becomes a maybe, when in full burn your getting between 150-170 and your pulling that back 40 degrees,   Just two many variable to walk away from.

it is certainly a viable plan worth looking at.

I have thought this over a bit more,  one important thing to remember, is with all basic Rocket stoves ( I don't know if they can be considered basic, but they do work along the same principals')   is that they do not require electricity to work perfectly well.  

Once you add a hot water system, unless you have done all the gravity calculations  or have that ability to do it ( generally meaning the heat radiators are above the heat source and never are shut off)  If you can't do this, you will always rely on electricity for your pumps?  

Something to think about.  An open water heating system solves some of this, but.....perhaps just another door opens to system design.

Hi all here.


Thanks for the tips, can you help me a little by a pic of other means what this bell is look like?

is it something like this on picture.

The coil is inside or between the walls? as you mention a double wall bell. Connected as
on the picture here.

thanks.

Here is the door I did mention.

Needs to get rebuild to a smaller one, so some welding.

Peter Pis wrote:ytong blocks are aerated autoclaved concrete
i am building 8" batch box

Why you do use these cheap build materials? porous materials? Do these
ytong blocks stand high temperature or use for floor of the stove, these blocks are
insulating because it is some kind of aircrete.

Maybe usable for me also, these are cheap.

regards

Hi Kees;
The picture you show from Peter's website would indeed work if water coils were in the brick box portion of that picture.

That, however, is not a double bell.
A double brick bell is a brick box like in the picture, with a second brick box built entirely surrounding the first box.
Normally a small gap (6mm) separates the two bells.
You can increase that gap to 40mm leaving plenty of room to install your water coils.

thomas rubino wrote:Hi Kees;
The picture you show from Peter's website would indeed work if water coils were in the brick box portion of that picture.

That, however, is not a double bell.
A double brick bell is a brick box like in the picture, with a second brick box built entirely surrounding the first box.
Normally a small gap (6mm) separates the two bells.
You can increase that gap to 40mm leaving plenty of room to install your water coils.

Oké now I have a good idea about it, because I thought that it was the version with a metal bell and pipes like on Peter,s site.
This batch has a oil drum, what happens when I do make a stone version around the batch rocket and there  gap and a second layer?
or get this to warm.

Mine idea as mention was using the flue pipe, a insulated one where I remove the insulation and put a rolled coil in place, or get the flue
to hot?. I think what you mention is better, the warmth is there present for a longer time, a flue version do cool very quickly.

On pic I let see the stones I have, much of it will be red bricks who I have not yet buy.

Your photo looks to be all firebrick, which is good as the upper portion of the inner bell should be constructed with firebricks.
The lower portion of the inner bell and the outer bell can be made of red brick.

I'm not sure what you mean when you mention the barrel, were you referring to the barrel in  Peter's photo?

Your Batchbox core is best situated inside the brick bells,  Superwool blanket is wrapped around the core to retain more heat.
You can expect inner bell temps to be well over 260C, and outer bell temps should be 90-120C
These temperatures are guesses on my part as I only have single-skin bells at home.

Check out this build 6" Batchbox with a double skin bell  
https://permies.com/t/238503/Batch-Rocket-Build

And this is the material list from that build
https://permies.com/t/248275/Batch-Rocket-Double-Skin-Bell

Scott Weinberg wrote:I have thought this over a bit more,  one important thing to remember, is with all basic Rocket stoves ( I don't know if they can be considered basic, but they do work along the same principals')   is that they do not require electricity to work perfectly well.  

Once you add a hot water system, unless you have done all the gravity calculations  or have that ability to do it ( generally meaning the heat radiators are above the heat source and never are shut off)  If you can't do this, you will always rely on electricity for your pumps?  

Something to think about.  An open water heating system solves some of this, but.....perhaps just another door opens to system design.

Hi Scott


I need pump, because I have no differences in high, I think radiators are even lower then heater so help from nature I can not use.

Not such a problem with a temp switch who do set pump on above 60 degree or so. The (isolated) lines from heater to radiators are go through a wall
and under the ground to the back garage where the rocket will stand, this is because I am not allowed a stove in the house, I
also use a radiator in the back against moisture.

regards

I don’t know but I suspect a larger air gap (very insulating) between a bell wall plus’s a flow of cool water may have an effect on the outer layer temperature?

Fox James wrote:I don’t know but I suspect a larger air gap (very insulating) between a bell wall plus’s a flow of cool water may have an effect on the outer layer temperature?

I do use a gap who is just enough for the pipes come in, I have not yet find out what kind of coil I have to make, a round is not possible
so it need corners, soldering these is a bad idea, maybe clamp system or hot welding, but maybe I can get corners also with bending
copper will do, because it is on a clean area without fire contact..

Maybe the kind of stones in the inner bell is a factor, less isolating types as example, like the red house bricks, can use a
blanket in the gap etc etc.

I presume I need to build the bell around the batch rocket, I need more then one fire a day and go use a 15 cm version
box so it keeps compact.

Fox brings up a good point.
Having never tried heating water with my rockets, my information on it consists of what Peter has mentioned and what I have read online. (Boom Squish)
As this stove is more intended for heating the water rather than his outbuilding, wrapping the outer bell with insulation might help.

thomas rubino wrote;
I'm not sure what you mean when you mention the barrel, were you referring to the barrel in  Peter's photo?

The barrel is a example, for me it is maybe better because I do place the heater in a barn and from there heat through pipes to the livingroom,
it is a way to do it because a wood stove in house is not allowed anymore, but a good system is quite environment friendly.

But oké, there are legal possibility and I need also heat in that barn to work there. Using a barrel give fast heat, I do not now it a bell
will be hot enough special when I use a double skin version, making a version with a barrel and a bell is then maybe a better way, I can always
try, so I have heat on 2 places in one go.

It is a challence.

Hi Kees;
The barrel will do a great job heating your shop.
The barrel will steal most of the heat and your water will not get as hot as you would like.

A Batchbox can be built with the core completely enclosed inside the bell.
A Batchbox can be built with the core extending beyond the bell, creating a flat spot to set a tea kettle on and allowing more radiant heat into your workshop.
The metal door of a Batchbox will share vast amounts of heat with your shop if it is enclosed in the bell or set out into your room.
The double-skin bell will also share heat, just not as quickly

thomas rubino wrote:Hi Kees;
The barrel will do a great job heating your shop.
The barrel will steal most of the heat and your water will not get as hot as you would like.

A Batchbox can be built with the core completely enclosed inside the bell.
A Batchbox can be built with the core extending beyond the bell, creating a flat spot to set a tea kettle on and allowing more radiant heat into your workshop.
The metal door of a Batchbox will share vast amounts of heat with your shop if it is enclosed in the bell or set out into your room.
The double-skin bell will also share heat, just not as quickly

Hi thomas.

What do a double skin barrel? a smaller into the bigger one and there the coil inserted some distance from?

just a idea, the pipe coil is 1.5 inch, it needs to be that big for safety, but this do fit.

Otherwise I go for the bell, and use  a flat top, this is a metal plate? workshop is quite big, there is a oldtimer car and a caravan inside
with some relax corner with a small bar. has stil to build from sandwich panels (isolated).

I think a mass who is 100 degree hot I do feel wel everywhere in the shop, I can afcouse do expermentations first.

kees ijpelaar wrote:

thomas rubino wrote:Hi Kees;
The barrel will do a great job heating your shop.
The barrel will steal most of the heat and your water will not get as hot as you would like.

A Batchbox can be built with the core completely enclosed inside the bell.
A Batchbox can be built with the core extending beyond the bell, creating a flat spot to set a tea kettle on and allowing more radiant heat into your workshop.
The metal door of a Batchbox will share vast amounts of heat with your shop if it is enclosed in the bell or set out into your room.
The double-skin bell will also share heat, just not as quickly

Hi thomas.

What do a double skin barrel? a smaller into the bigger one and there the coil inserted some distance from?

just a idea, the pipe coil is 1.5 inch, it needs to be that big for safety, but this do fit.

Otherwise I go for the bell, and use  a flat top, this is a metal plate? workshop is quite big, there is a oldtimer car and a caravan inside
with some relax corner with a small bar. has stil to build from sandwich panels (isolated).

I think a mass who is 100 degree hot I do feel wel everywhere in the shop, I can afcouse do expermentations first.

What do you intend to make a pipe coil at 1,5" dia. From? And that big for safety?    Where are you determining that bigger size makes it safer? If copper, I suggest looking at price. You suggested yesterday that you didn't feel soldering would work? so why you think that?  Thus my thoughts on copper,  

Somewhere along your forum subject, I thought you decided that a double brick bell would be best,  but perhaps your at the metal and a brick bell, if so where do you intend to put the coil, to be both safe and get the intended results?

Mass temp goes up and down depending on what is demanded from it and what is put into it.   What - how much mass and for how long do you expect to be 100 degree hot ?

Just curious. on the above, followed by sizing question below.

How many BTU's is it presently taking to do the heating your intending?  This is very important, as certain size stoves will produce X amount BTU's per burn.  Lets say you can put in 6 kg grams of wood, and get get 8000 btu per kg.  ( someone correct me if this is way off )  But if this is right  You can do the math,

Hi Scott


I did mention the diameter of the pipe after I read that a bigger one is more safe, but it seems
that is not the case, I just need to good design who is save.

Soldering is fine, I need to find out how many windings I need, there is maybe some tool for,
solder do not loose itself, the heat for that is much lower in a bell. but maybe the pipe
a copper one can be easely bend in the corners, so maybe no need for soldering, but need
a bend tool..

Yesterday I was oriented in a store, and what kinds of stones, I do go use a double skin bell
as mentioned, the inner stones I can use type with holes in it, maybe that do warm more quickly
but maybe that is also not the case I have no experience with.

On the pic I had drawn these but that was before I was not allowed anymore to put one in the
livingroom, because it is not green, but that was this one, I like the design. It is however
not for this project, it is old one..

I go draw the batch into sketchup and let it see here again, till then.

I need to sell mine greenhouse, I have to much hobby,s and need a bigger workshop, both can not
so if dutch members are here it is available, it is new and quite big 2.20 high and 4 x 6 meter.

Then there I can expand workshop and use a heater who do also the room and barn.

thanks.

Oke the bell work again.


I have done some drawing but when I put a bell around the batch the thing get very big, that is a problem,

Can I make a smaller bell, and only around the rizer, how much space I need between the rizer and the first
wall? because it is not that easy. This way I can make a perfect square bell, and the coils fits better in it.

I can isolate the part of the box outside the bell easely and wrap metal around it with the door, even vermiculite plate
I can use there.

The riser is also isolated of course.

I use a SketchUp from peter site, with firebricks, I can make a round rizer from other materials, or the stone, but a lot of
sawing. I do draw and post it. It is not yet with floor isolation that I do draw later, maybe a bed of vermiculite with thin
firebricks or other cheaper ones.

I did see this on the peter channel, looks not that big and I see now how it has to be done, incl the dimensions inside of the box
the bell need no even distances around.m Also I see the bricks are standing up in stead of ly down, so we need less stones,
and the wall is thinner and more warmth get through to waterpipe.

https://youtu.be/N8zXM7gpshY?si=fw8Y-Key424kQd90

regards.

Peter Pis wrote:Hello,

i am working on my first RMH and am wondering about the temperatures inside.

I found information that temperatures inside the core can go up to 1000*C. But what about other parts of the heater ?
- what is typical max temperature at the top of the primary bell ?
- what is typical max temperature at the bottom of the primary bell (floor) ?
- what is typical max temperature at the top/bottom of secondary bell (bench) ?
- i found information that chimney temperature will usually go between 60-100*C

the reason i am asking is so i can better choose the materials:
- to isolate the floor. the heater will be build in the room with concrete floor, i don't want the heat escaping into it, so i want to build a proper insulation layer below the heater.  I saw how perlite can be used but i am worried about building on top of loose perlite so i would prefer to use something load bearing. I was thinking about using YTONG blocks covered by a layer of concrete made out of cement and perlite.
- to isolate the back wall of the heater and bench which is going to be build against the wall stone of the room. I was thinking about double skin bricks with a layer of ceramic wool in between them. I don't like it so much as there is still one layer of bricks absorbing the heat there. I was thining about using ytong blocks instead of bricks for the back wall of the bench, still doing double skin with ceramic wool in between. ytong blocks are ok up to 600*C, so i want to be sure temperatures inside my bench are not going to reach that level. I am wondering if i could do the same for the back wall of the primary bell ?

any other suggestions on how to insulate the floor and back wall ?

thank you.

Peter Chauffeur wrote:

Peter Pis wrote:Hello,

i am working on my first RMH and am wondering about the temperatures inside.

I found information that temperatures inside the core can go up to 1000*C. But what about other parts of the heater ?
- what is typical max temperature at the top of the primary bell ?
- what is typical max temperature at the bottom of the primary bell (floor) ?
- what is typical max temperature at the top/bottom of secondary bell (bench) ?
- i found information that chimney temperature will usually go between 60-100*C
the reason i am asking is so i can better choose the materials:
- to isolate the floor. the heater will be build in the room with concrete floor, i don't want the heat escaping into it, so i want to build a proper insulation layer below the heater.  I saw how perlite can be used but i am worried about building on top of loose perlite so i would prefer to use something load bearing. I was thinking about using YTONG blocks covered by a layer of concrete made out of cement and perlite.
- to isolate the back wall of the heater and bench which is going to be build against the wall stone of the room. I was thinking about double skin bricks with a layer of ceramic wool in between them. I don't like it so much as there is still one layer of bricks absorbing the heat there. I was thining about using ytong blocks instead of bricks for the back wall of the bench, still doing double skin with ceramic wool in between. ytong blocks are ok up to 600*C, so i want to be sure temperatures inside my bench are not going to reach that level. I am wondering if i could do the same for the back wall of the primary bell ?

any other suggestions on how to insulate the floor and back wall ?

thank you.

Here are some pictures og what I’ve noticed on my “Frankenstove Mark 5” gravity pellet fed vertical rocket mass heater with a 4” ceramic core.

Hi all


I have drawn some things in sketchup.

This looks a lot better, I have for the inner bell flip the bricks, standing up, the outer bell she are flat as normal.

regards.

Hi there all


I have now done some more drawing, looks like it go look good and also compact.

I am also busy with a heater who is for emergency what is now happening, the cold is to
bad an it is wet, The barn is not yet compleet closed so I want to set a barrell as a heater,
I did drawn 6 inch rocket j tube for that, but I think I can better do make a turbo heater with
a long tube of 4 cm who is 12 cm above the bottom to inject heated air.

Not as clean as a rocket but if I want to do use J tube it just get to heavy, maybe use mortar
based J tube with isolation or aircrete can work because it is removable.

The riser is chamotte isolated plates I can saw it from. But can also use other stuf.

pics the other more important one for the next winter.

Hi Kees;
Do you intend to use an upper Peter channel for the secondary air supply?
Most builders of the first-generation Batchboxes have switched to using a floor-level secondary air and the smart ones have duplicated my quick-change stub riser design.

Hi thomas


I have this as a example, the batch was a already drawn version I have just use, I can afcourse
change that, I think when use a floor tube it is much more heated and get better burn, but it will
burn to damge quite quick, maybe use here rvs is a better way, but oke, replace it is also
very easy, just pick and place.

Hi Kees;
Yes, it is very easy to change the secondary tube with my design.
But, if you spend a bit more money.
I can sell you a lifetime stub riser, made from extremely high temp metal and you will never need to replace it.
I offer the well-known highest-rated RA330  ($90)
I also offer a much more reasonably priced RA253ma  ($60)
I replaced my  RA330 stubs in my extreme burning Batchboxes with the RA253ma  stubs two burning seasons ago.
With no spalling after two years of hard use, I can confidently sell these as a lifetime riser stub comparable with the more expensive RA330

Being small, light, and very common-looking, I can ship these worldwide with low or no VAT, duty, or import taxes.

Most of the time usa have high costs for shipping, these are also available here,

rvs 310 can withstand 1150 degree is also quite high.

Vat do need to be paid always, the douane here do intercept all, and sometimes make
the shipping also lost is mine experience.

I go first try if the heater will work for me, making a rizer with isolated 1400 degree stones.

thanks for the offer.

Hmm I was confused about this, thought it was the riser, but is the channel.

kees ijpelaar wrote:I have now done some more drawing, looks like it go look good and also compact.

It may look compact, but the core is too large for the bell. Or the bell is too cramped for the core. In order to build a bell like that for the core, the heater will be very high.
Building a wider bell so the gases will flow freely down the sides would help already. It would be even better to lift the core from the floor to such an extend that it's above the exhaust opening.
For a well-proportioned bell: see https://permies.com/t/238503/Batch-Rocket-Build

What you could do is scaling the core down and leave the bell size as it is.

Peter van den Berg wrote:

kees ijpelaar wrote:I have now done some more drawing, looks like it go look good and also compact.

It may look compact, but the core is too large for the bell. Or the bell is too cramped for the core. In order to build a bell like that for the core, the heater will be very high.
Building a wider bell so the gases will flow freely down the sides would help already. It would be even better to lift the core from the floor to such an extend that it's above the exhaust opening.
For a well-proportioned bell: see https://permies.com/t/238503/Batch-Rocket-Build

What you could do is scaling the core down and leave the bell size as it is.

Hi Peter.

First the best wishes. gelukkig 2025.

I am happy with your respont as you are the inventer, I had already this kind of question about how big the space needs to be inside around the core.

As you did read already I need a heater who can heat a cast radiator('s) in the home, for this I need a heat exchanger made from copper tube,,
I need a kind of heater not to big, and safe because of danger of steam explosion, however do not happen this way, taking heat from between the walls
but it needs to be hot enough because a pump do pump continuously..

The core is your design, and is a 15 cm rizer version, when go smaller, I did read that it burn less good. but also smaller wood. there is somewhere
a sweet spot here?.

Or I can use a rocket mass heater, who I like very much, and a way to exchange heat from,  also with using a bell. then it can be much smaller but needs
to get hot enough for the water but not to hot.

Th drawn I did, and then the lower part, I do now this needs to be lifted, but for clarity I did keep that away.

thanks for your advise.

Hi Peter


I have redrawn the system to look at it, and I did read a space of 13  to 18 cm is oke?

new test draw.

The system is for heating water and pump it to the living-room into a  old cast radiator
maybe two to handle weight, is there maybe even better ideas? I see people wrap pipes
around a normal metal stove and warm the floor, and do already for 3 years.

Safety is all, system needs to have a working pump and never get dry to prevent steam,
idea is using a pressure sensor who can shut a air supply to the heater and give a shutdown.

This works only for fast heat systems and not stone accumulation systems, these will keep
warming up for some time, using a barrel will cool down fast for example, a rocket system
who get shut off oxygen just stops fast.

pic of that stove is a old wood eater and stinker I do never use , but as example. the tube
around it is the idea for the brick bell batch rocket, I have also draw a smaller version for a
100 mm pipe, but is this not a little small?.

corrected pics for batch 150mm

regards

kees ijpelaar wrote:



The system is for heating water and pump it to the living-room into a  old cast radiator
maybe two to handle weight, is there maybe even better ideas? I see people wrap pipes
around a normal metal stove and warm the floor, and do already for 3 years.

I want to clarify on this a bit, and some great advice has been given to you, about the pipes/coils or means of picking up heat with the water, With the double bell, being what I thought was the resounding winner?   Have you decided none of this is what you would like to do?

kees ijpelaar wrote:
Safety is all, system needs to have a working pump and never get dry to prevent steam,
idea is using a pressure sensor who can shut a air supply to the heater and give a shutdown.

Getting dry is not the problem,  getting your water above boiling temp is where steam begins and is a huge problem.  If you rely on a pressure sensor, to shut off air supply, it will most likely be to late.  While I know pressure sensors are out there, what device were you thinking that could shut off the air supply in such a fashion, and to elaborate more,  if you require power to keep the air supply open, then do you have something for when the power goes out?  Or the exact opposite.    As has been explained, the beauty of Rocket Mass stoves- Masonry heating devices or what ever term you wish to use, is that they work just as well with NO power.  

By the way, if you have your coils  in between two bells,  and even if you could instantly shut off the fire, having the heat inside your stove, instantly stop migrating, will be a trick.   Think of a bell curve in your bell temp on a graph,    if steam starts before the peak of the bell curve, the heat is going to keep coming for a bit... NO instant shut off.    Look at a auto mobile, you never know the radiator is going to blow, until it does.  it is the expansion that kills.

I know you know all this already, but it should be pointed out to be sure.

To take this further- if you are going to rely on power for the pump, what happens if you loose power?  Preventable problems should be just that- Preventable. This sounds like " I hope it works, unless it don't"     I presume after researching it this much, a open system that uses the fact that hot water rises, could be a possibility, but I think you have ruled this out.

kees ijpelaar wrote:
This works only for fast heat systems and not stone accumulation systems, these will keep
warming up for some time, using a barrel will cool down fast for example, a rocket system
who get shut off oxygen just stops fast.

I would not bet on a "fast heat system" being able to shut down instantly before a problem based on pressure as you stated, maybe something connected to temp sensor.
But basically you have posed your question to a group of rocket mass individuals, and it looks like your posing a question about fire wood heated boiler.

Hi Scott


Yes I want to do what you and others did advice, but I do also look at some more things special for learning also.

problem is that the heater get quite big for a barn where it resides and with pipes the water get into the home radiators.

These pipes under ground with isolation around it.

Here I have a change in  the draw to see if it can be smaller, when using a small core like 100mm I think this is to small.

The gap in this drawn is as big as the copper pipe is, maybe a little bit bigger for easy install. The stove met the copper pipes is
a model for me, because as you see the pipes can also done this way in the gap of the double bell.

The barn who has still to get build has a old-timer in it and a folding caravan, so it get extend 2 meter. it is 220 cm high
and has a L form around the existing barn. one side is a living corner., little bar and such. The greenhouse needs to be
removed and sell this if there is somebody interested.

Pic also contain a shoe form of the batch rocket, is this not a good way to get it more compact? this one I do not need a gap
for the gasses, because it has a upside burn system. I think here I can make also a nice one.

That is what I do look at, not to big, reasonable fast heat.

project is for next winter.

regards

For Peter

where I can best buy stuff for the heaters? like stone and mortar/concrete. I did see the prise differences
are enormous.

thanks.

Hi All


As the batch system is fro the next winter when the barn is ready I need now a heater for work I have to do
on the rover P6.

I have seen a video where the core is made from refractory cement, perlite and cement, I have no perlite but vermiculite
in a bag, I do not now if this is usable.

Have to make the refractory stuff, it is the chamotte cement in the 5 kilo bag as on picture, and fireclay with perlite.
I need more of this I think.

Question is can I use this cement seen on picture and mix it with fireclay and perlite, (need to get perlite if vermiculite is not
usable)

I have made the  box from wood for the core build, with 8 cm thick walls, need to for isolating, this together with a 8
minute rizer who consist of a 200 tube with 25 mm isolation blanked.

So I make a movable heater that way I keep neighbor as a friend and I have heat for mine work without smoke and stink..

Let me  now how to do the refractory part mix. I have let go the pocket rocket, to dangerous for so close with me.
Possible I only need the cement as on picture because it has already chamotte grain, clay and aluminium cement.

It is like here.



thanks.