rocket mass heater in bartell's bunkhouse - design

this is a placeholder so design discussion can begin.

a quick drawing while I was up there one day trying to get a rough idea of a design.

This is small space.  And a situation where there were no real good choices for placement.  I didn't want the barrel close to glass.  And then the exhaust will have a fair bit of near horizontal run - because you do not poke holes in the roof of this sort of structure.  

A six inch j-tube, with cob.  The vertical exhaust will be close to the barrel (hopefully, touching).

Mud made a drawing.  I have modified it while on the phone with him.

Here is what would be to the right of the images above.

This will be a 6 inch core, with 8 inch duct acting as a stratification chamber, with a juice box style stratification chamber at the end.



We also are choosing to keep the "L" at the end.  

Since the space is small, would the proposed design allow cooking as well as heating? Or would that need to be a separate build?

Mark Brunnr wrote:Since the space is small, would the proposed design allow cooking as well as heating? Or would that need to be a separate build?

At the moment, I am thinking of just heat.

Here's a floorplan and head-on view of the space for the design. Both dawn to scale

mud and i made a rough design

Here's the space we're designing for:

So Christina Keegan and I are looking at filling the small space in the bunk house with a single cob bench heated with a 6" rocket. The radiant barrel is 16 gallons so relatively small. The pipe buried in the bench is over-sized at 8" with a 4" vertical exhaust sipping out of the bottom of its far end to test Paul's theory that we can get a little stratification chamber action out of it.

Hey Mud, what about some half barrels instead of the 8" duct?

A single cylindar made from two barrels attached at their open ends would work very well.

Just a platform?  Like you want to go a bit lower and make the floor heated?

Our plan is to have the platform at bench height so it is comfortable to sit on at the edge (where the big stones are) and comfortable to stretch out on and easier to get up and down to the bed from.

It seems like about double the work and you end up with a platform.  Or a sort of raised floor.  

I like the idea of the bench because this building has nowhere else for people to sit.  

Here is a slight variation.  Smaller bench means simpler project.

I might have went a touch overboard playing with Sketchup ... I finally found a site that allows for 3D model viewing (limited to 10 uploads within a certain timeframe for free accounts.)

Unfortunately the .STL file doesn't seem to transfer over the 'materials' - so a lot of visual information is lost in transporting from sketchup to sketchfab this way.

Bartell's Bunk 3D Model Mockup Turn Around

I used Grey's drawings to work to scale , the roof is a little strange - I used the photo references to get it close in areas that I didn't have measurements.

The RMH I designed is totally tentative. It is a 16 gallon 'barrel', 14" diameter with 8" diameter tubing underneath the casing (appears blues in the later screenshots to allow for translucency.)

I didn't want to eat up more time trying to make the 'J' shaped flue / pipe connectors - so please engage your imagination for the corners. 😅

I don't really expect my design to be used for this project, but I still enjoyed the prompt for design and maybe it sparks inspiration for someone else!

EDIT : Oh and if anyone wants the .STL file to play with , just let me know and I'll figure out a way to send it to you to play with ! ☺️ It should work in Sketchup and FreeCAD and any other program that opens .STL files.

Looks mighty fancy!  

You have the exhaust going through a wall - that has dozens of tons of dirt there, so I think that is not gonna work.

Here's the build as of lunchtime on the last day of the event. I'm learning lots of stone, cob and clay mortar building techniques from Christina. I shall not dismay and see this rocket mass heater finished!

In the couple of weeks since the event ended, more work has been done. While not nearly as polished as I hope to get it, I believe the RMH in Bartell's Bunkhouse may now be considered complete!

Talyn Crafts wrote:
EDIT : Oh and if anyone wants the .STL file to play with , just let me know and I'll figure out a way to send it to you to play with ! ☺️ It should work in Sketchup and FreeCAD and any other program that opens .STL files.

I would like a copy....I need practice of playing with other's files too  (importing, viewing, and maybe editing).

twobirdstone at gmail

from Stephen's BRK thread.