RMH with two benches?

So.... say you want to put your rmh in a corner and you want to consider having a bench going down each wall... Doable?  Can you split the ducting to go into two benches?  What might that look like?  Just doing more 'what ifs' in my head.    The idea was to spread the thermal mass over a greater area.  Obviously, the more mass you're heating, the more weight and fuel and time to bring the extra mass to temp.  But if those weren't major issues to someone's build, what would that look like on the inside?

Thanks for playing along with me. :)

Certainly, that is doable.

Here are some threads to get you started:

https://permies.com/t/23699/dual-benches

https://permies.com/t/71352/plumbing-corner-built-MRH

https://permies.com/t/139768/Heated-bench-firepit

In the old days, those benches would have pipes and be filled with a solid mass.
More common now are "bells" where your benches are empty and brick/stone absorbs the heat and shares it with you later.

Hello. I would love to get some feedback and corrections. I am a bit overwhelmed to come up with a design that fits our goals and specifics ...

Regarding a (batch) RMH with two benches, in an L-shaped arrangement.
Assuming we go with updated generic recommendations of:
-no ducts inside,
-convergence of both exhaust lines to a central chimney/ flue next to the barrel
-same bench lengths

and alike bench conditions (other factors)

1. what is the best way to design that hollow bench?
As I do understand it hot air must reach the end of the bench and come back towards the chimney, so I imagine there must be some partition inside in the absence of ducts, either:

-horizontally: so hot smoke would flow from the riser into its upper partition and as it reached the end of the bench it would turn 180 into the lower one and would continue its way back towards the barrel/chimney/ exit area
-vertically:
-another arrangement?

2. if there are such partitions inside the bench, there would be a 180 degree turn for the smoke, hence possibly creating some friction. What would be the consequences? Would I have to adjust the ISA somehow?

3. If one of the benches is placed next to a structural uninsulated wall of the house.
What should I do to generate alike conditions for smoke to flow equally inside each?
I thought of
insulating the section of the wall next to the bench,
leaving an air gap between this wall insulation and the bench
making the back of the two benches  out of a more insulative material (possibly cob) while the front part is made out of stone and clay mortar.

Hi David;
The super-heated air leaves the riser.
The hottest air travels to the top of the hollow stratification chamber (bell).
Where it is constantly being displaced by hotter air coming from the riser. That cooler air then sinks toward the bottom of the bell.
Upon reaching the lower level, that still-hot air seeks a way out locating your chimney entrance also located near the floor.
Having shared its heat with the bell, that air rises up the chimney and out of your building.

Thanks a lot. Nice when things are simple. Got it, so no need for any partitions inside the benches

Is the goal 2 separate runs with a diverter/damper letting you heat one at a time or are you doing it one run?

Thanks for your interest. I try to make it as simple as possible. No dampers. One run. I would only consider dampers if I was told I can't create alike conditions for both benches.

The sheer number of elbows is going to limit the length of your runs and probably reduce the effective bench size.

Anne Miller wrote:Certainly, that is doable.

Here are some threads to get you started:

https://permies.com/t/23699/dual-benches

https://permies.com/t/71352/plumbing-corner-built-MRH

https://permies.com/t/139768/Heated-bench-firepit

The second link has a link in the second post with a cutaway 3D model that helps a lot with seeing how the design works. As someone in Florida with little need for a heated bench, I hadn't kept up with this and never saw this design before. Great stuff!

C. Letellier wrote:Is the goal 2 separate runs with a diverter/damper letting you heat one at a time or are you doing it one run?

Preferably with one run.