Ducting of 130mm

Hello

I have just joined the forum

I live in Bulgaria in a village where the prime heating source is the buring of wood in a small wood stove


I would like to configure , if possible a system that can be used ( is affoprdable )  by fellow villagers and also friends in surrounding villages


13cm ( just over 5 inches )  flue ducting is the most common here for stoves and quite cheap , whereas 15cm and 20cm is a lot dearer


Does anyone have a system using mass storage using this size ducting , and what mass storage  / duct length hass been possible

The angles 90 degree are corrugated style also but I am searching for non corrugated angles


Ron

Hi Ron;   Welcome to Permies!

Do you have a copy of the RMH builders guide ?  It is the go to book for all new builders! Written by Ernie &Erica Wisner, it is readily available from Amazon. Worth every penny !

With a 5" (13 cm) pipe I think you would want to build a brick bell (stratification chamber) rather than a flat mass with pipes. No 90 degree bends needed.
You could build a 5" batch box stove and if you have a tall insulated chimney you might be able to build  a 6" .  
Or if you prefer a more simple construction, then a J tube RMH is easier to build. They too can be run into a brick bell rather than thru piping.


To clarify)   A stratification chamber can be anything.  I prefer brick as it holds heat well , but 55 gal barrels cut length wise in half can be used , a large metal tank can be used. Any enclosed box you can run heat into.

Hi Thomas

Thanks for the reply

I am really wanting to contruct something that can be easily replicated by many of the people in the villages

Many of them are getting on in age and spend sometimes more than 4 months pension on winter wood

It would be nice to see them warmer and have a bit more money left from there pension as well as the obvious benefits to our resources here on earth.


Today I found some reasonably priced 15cm flue pipe hich should be fine.


I am thinking of refractory bricks for the feed and chamber and refractory tubes  4 x 33cm for the riser

I am wondering if I need to insulate this ceramic pipe I am using for the riser


This should fall within many peoples budget if they use local workers


I am going to install a system in my house to warm one bedroom and take the ducting to feed the bathroom hwere it will rise in a duct to the internal chimney

This should be 7 metres of ducting ( within the mass storage ) with only 2 x 90 degree angles which are smooth profile , with one 45 degree as it enters the wall for the chimney


I will have mass for storage in both rooms

Just working on my insulation materials at the moment for the floor , back walls and also where it passes through a brick wall to the bathroom.


Ron

Hi Ron;
Good deal on finding the 15 cm flue! Now you can build a 6" RMH

Your ceramic riser)  It would depend on its construction. If it is heavy and dense then it might need extra insulation (fiberglass) wrapped around the outside. If is lite then I would think you are OK.

If you have plain fiberglass easily available a wrap around your riser held on with chicken wire  would certainly not hurt.


Are any of your refractory bricks the lite insulated kind ? Or are they all the heavy dense brick?  If you have both kinds of brick you would use the lite ones inside the burn tunnel and the heavy ones in your feed tube.


The plan you describe for your home sounds like it will function as expected.

Hi Thomas

Thanks for that

I have available used light bricks and also dense bricks , the tubes is not here yet but 33cm x 16cm internal is 5.2kg in weight

Ron

That seems heavy Ron,  44 lb for 4 sections stacked. I would plan on a wrap of fiberglass / rockwool .   Does each section "join " the one below or do they just sit upon each other ?

Yes they slot into each other the top has a slight groove and bottom proud

This sounds like a great project. Please keep us informed on your progress.

Ron Curtis wrote:I am thinking of refractory bricks for the feed and chamber and refractory tubes  4 x 33cm for the riser

Ron, those refractory tubes aren't suitable for use as a riser. They will crack, quite badly due to uneven heating. This could be alleviated to some degree by making one slit lengthwise. No guarantees it won't crack this way but they're stand a better chance to stay undamaged.

Those pipes are perfect for a mass bench though.

Thanks Peter

Have not ordered those yet so appreciate comment


Ron

Ron, i have used those, few times.

And they can be used. But it is better to provide for  easy  replacement. I would advise you to make a batch box.

Check my building technique on this one.

https://permies.com/t/44806/Cobbling-workshop-heater

You might have to reload several times, as the post is pic heavy.

But i bet the "fuel tanks" are available in your country. They make the mass very easy to build. And having the window in the "barrel" makes your chamote riser easy to replace.

Only thing i would do different,  put the riser to the side, to use that window as a oven.

Interesting design not sure I have skills for that

I also want to make something that is within the reach of the people here in terms of cost and skillsets

Ron Curtis wrote:Interesting design not sure I have skills for that

I also want to make something that is within the reach of the people here in terms of cost and skillsets

It's pish easy for the core, all dry stacked.

The slot from your burn area to the riser is quite narrow

How did you calcualte this as part of the RMH

What material did you use for sealing

Looking at the top of the first tube in your riser it looks grey

I am unsure what to use having read the guide for building as it says there are lots of types of clay , some of which are not suitable ( expansive ) and will crack

I was looking for 130 mm pipe a couple of days ago to build my 5 inch rocket stove.  In the end I used a wire mesh to form a 7 inch diameter pipe and slid the ceramic fiber blanket inside to make the "5 minute riser".  
So, using firebricks and a 5 minute riser, anyone can build a core for a rocket mass heater in an hour or so.  Easy to replicate.  With 130 mm pipe I would have wrapped the blanket around the pipe and then burnt the steel pipe out over time.  I presume that's acceptable

Graham Chiu wrote:With 130 mm pipe I would have wrapped the blanket around the pipe and then burnt the steel pipe out over time.  I presume that's acceptable

Over time, the steel pipe  will deform badly, pinching the flow and disturbing the burn process until it finally collapses. Which means there's at least one burn season the heater won't work properly at all. Been there, done that, learned from it.

Ron Curtis wrote:The slot from your burn area to the riser is quite narrow

How did you calcualte this as part of the RMH

What material did you use for sealing

Looking at the top of the first tube in your riser it looks grey

I am unsure what to use having read the guide for building as it says there are lots of types of clay , some of which are not suitable ( expansive ) and will crack

What you mean sealing? It's all dry fit.

For the measurements, there

http://donkey32.proboards.com/thread/734/peterberg-batch-box-dimensions

or there

http://batchrocket.eu/en/

My riser pieces are salmon in color, and are from tona in italy. Sold by schiedel. as a kit with insulation and pozolan elements to hold the whole stuff together.

Hi

Thanks for feedback

What material is surrounding your riser in enclosed pic?

What did you use to seal manifold?

Ron

Sorry, my bad.

The yellow stuff is rockwool. I can't remember if i have put any around the exhaust. Most certainly.  And the exhaust is in pourred concrete.

Tho, there is nothing very air tight. As with a proper chimney, all the system is under underpresure.

Your design made me think I could do something more with mine

I have a pool room behind where the RMH will go and thought of creating a firebox ( above the RMH Barrel ) and drive hot air to the pool room

All rooms are insulated with 10cm and I was wondering whether the barrel would overpower the 6M x 5M metre room

This way i would get up to three rooms heated which makes the build a lot more attactive

Downstairs Bedroom / living area   6M x 5M
Bathroom   3M x 2M
Pool Room  12M x 6M

I was thinking also I could take a hot air duct from the firebox to one of the upstairs bedrooms above and have either pool room or upstairs bedroom heated or at least have the option to do so.

I may need to supplement the pool room at times with my central heating or aircon which has a COP of 5.79  and ticks over at about 600 watts in -2 temps

Very exited about RMH though due to it's efficiency and mass storage

Ron, just to make you grasp what it is able to.

I heat the workshop with the flat above with it. 635m3 113m² at the workshop level, 55m² for the flat level.

12cm cork insulation in the rook.  Badly insulated walls. If at all. 20cm hollow bricks all around, Bare on the south east side. Insulated with strawbales  for all the other walls. With gaps, thermal bridges etc. Nothing good at all. Altitude 1500m in the alps. Down to 0C°, i do two fires a day, 32 kilos,  down to -15/-17C° i do three, 48kg of wood,around -20C° i do 4 fires a day. 64 kilos of wood. that's from october to may usually.

Thats impressive my central heating wood burner would use that amount of wood for a lot less space

How do you get the heat to upper floor

What size of mass do you have in those areas

Convection for heating upstairs.

Ans i have 4 metric tons of mass aproximately, not counting the wall behind, nor the chimney.

I was thinking of mounting an open bottom barrel on the main barrels , sealing it to keep pressure then having and input duct with a 'push fan'   and one or two outlet ducts maybe with a baffle to open or close to eiother bedoroom or pool rom

Have you done anything like this in the past , I was wondering how much heat wouyld be tranferred to the air in the second barrel , and at what temperature


Also could this ' clean ' hot air be passed through a mass in the pool room ( give a reasonable amount of heat to the mass )  before venting to the room do you think

Korean design I saw on youtube , would be interested in comments on design

https://www.youtube.com/watch?v=GkHOwmKyL7A

Hey Ron ; Wrong video,  this is the portable free cycle rmh not a Korean design. :)

This is the one

https://www.youtube.com/watch?v=NaZtGVhSmNo

No insulation or anything but was interwsted in views on concept


anti smoking commercial before video

Cool video Ron;   Seems like you would need to keep all three burners running all the time, or it might want to vent through them.  Those guys need to learn to build a big batch box to run that system.  

I was interested in the fact that it had no barrel , just another chimney on the back side

Well that's a brick bell.     Longer heat up but longer at holding heat.

I think I understand ....not sure

If that was one burn area and hence it was 1/3rd size , would that be as efficent as a barrel ( albeit longer term for instant heat )


If so it seems a lot simpler and negates having / sealing a barrel and all that goes with it


Is this correct?

Yes, the barrel releases its radiant heat instantly and transfers the rest into the pipes and mass.
You can build a standard rmh with pipes and mass using a smaller brick bell in place of a barrel.  Down side is it takes longer to Feel any heat. Plus side is it holds that heat longer.

If you want to use a larger brick bell. Most folks do away with pipes & solid mass altogether. The large brick mass has a lighter weight and a smaller foot print than a solid cob and rock mass.

A smaller brick bell in the living area and another in a sleeping area is a good way to go...   Your choices are endless...

I read that part of the benefit of a barrel is that it creates a cooling effect on the gases and hence a downdraft

Is it the same case with a bell that cannot release heat for some time?

When building a bell you increase the top gap of the riser. No problem with "stalling" the flow.  Hot air goes up, cooler air sinks , with a bell design the exhaust exits at floor level.

thomas rubino wrote:Well that's a brick bell.     Longer heat up but longer at holding heat.

I wouldn't call it that.

Updraft and downdraft channel. Here the gases are forced down in three channels or a big channel.  I can tell you it's harder to start than a bell. Plus, in this case it can't realy be called a bell, since each channel is no more than 3 times the CSA of one burner. When a bell needs to be at least five. For the stratification to occur.

And a bell is not all or nothing - you can put a metal access panel in it and get some instant radiation, or add a barrel bell after, just before the chimney.