RMH for 2 yurts?

Hi everyone,

I’m new to the forum and to RMHs but really excited to dive in… In the spring, we plan on putting up two 21’-diameter yurts to live in and we want to heat them with an RMH.

I’m intimidated by all that’s out there on RMHs and am hoping I can get some suggestions for what RMH design would be appropriate for our situation…. (Once I’ve determined that, I’ll need to educate our building code enforcer about RMHs and the one we want to build so that he has enough information to “perform a comprehensive inspection of the installation in order to sign off on it.” Once he’s given us the ok to proceed with the RMH, I’ll work on learning how to build it…)

Here are some details for our yurt plans:
- We’re purchasing the two yurts from https://yurta.ca; they’re each 21’ in diameter, translating to about 346 sq feet per yurt, for a total of 692 sq feet.
- The yurts use 100% wool insulation lining (F11 wool), needled to 1/4-1/2” thick
- The yurts will be on a single raised wood deck (that has wood siding around it to keep wind out from underneath).
- I’m not sure what the interior floor will be and how we’ll insulate the flooring – that will be another thread… (I’d love it to be an earthen floor if that’s possible and wise…)
- The yurts will be connected to each other (there will be a doorway going from one to the other).
- The current plan is for one yurt to have the kitchen, living room, and small office/guest room, while the other yurt will have the bathroom and a bedroom (we might try to put a lofted bed on top of the bathroom), though the floor plans are still evolving and we're open to making changes….
- We plan on living in these yurts for the foreseeable future, but it’s possible we’ll get tired of it and need to take them down or move them to make room for some other structure (we live in an intentional community and have only a small lot on which we can build a home, so there probably wouldn’t be room to build an additional structure next to the yurts). So it’s possible that we may need to remove or relocate the RMH in the future…
- We live in Danby, which is near Ithaca, NY – Zone 6
- I have no background with building RMHs or related skills. I'm eager to learn, but am hoping for an RMH design that's beginner-friendly...

My two questions are:
1. Can we get away with a single RMH or should we go with two RMHs? The yurt company (Yurta) says that most of their clients heat them with wood stoves but that you’d need a separate wood stove in each yurt. If using a single RMH, would we need to somehow run piping (maybe through the floor and wood deck?) to a thermal mass in the other yurt?
2. What RMH design should we use? Would a pebble style make sense because it would be easier to disassemble if needed? Or one of Uncle Mud’s Cottage Rockets? Something else? Relatedly, I’m also not sure if we should be going with an RMH designed for a smaller space (given the size of the yurts) or with something designed for a larger space since the insulation in our walls will be relatively low.

Thanks so much for your help!

Matt

Hi Matt;
I suggest two RMHs,  one in each yurt.
For ease of building, J-tube rockets are very simple to build. I suggest an 8" as it gives you 45 minutes between loading and allows using larger wood.
After your first winter, you will love your RMHs BUT... you will probably wish they burned a bit longer.
That is when you convert one or both over to 6" batch boxes!  Batch boxes easily last 2 hours unattended.
They burn hotter than a J-tube although you lose the throaty Dragon roar that the J-tube produces.
A 6" batch box lengthen out to allow standard-size 16" wood is an excellent stove!
The batch boxes are easy enough to build, but they do require some metal parts.
You can build your own if you are handy with a welder OR better yet you could buy them premade from me at https://dragontechrmh.com/
No matter what style RMH you choose to build, you will seriously wonder why everyone does not have one!
And you will be darn glad that you have not one but two keeping you cozy on long cold winter nights and short cloudy winter days and oh yeah don't forget, the butt loads of snow.

Hey Matt;
A couple of things.
First, always talk to your code enforcer about the Masonry stove that you want to build.
That is terminology that they are familiar with and codes they can interpret.
If you talk RMHs they will be confused... you want your inspector happy, not confused!

Next is piped mass versus a brick bell.
RMHs are evolving, and pipes thru a mass are being replaced by a stratification chamber (Bell).
These bells are commonly built using clay brick but can easily be a large metal tank with mass inside or around the outside.
A brick bell built with clay mortar will disassemble quickly and easily, and all the mortar can be reused!

Here is a new fun video from the free heat movie you might enjoy:

Thanks, Thomas and S Rogers!

Thomas - you do make the batch boxes sound more appealing... Is there any reason I shouldn't just start with that instead of the J-Tube?

And thanks for bringing up the question of piped mass vs a brick bell! I don't remember coming across brick bells and will have to look into that... Any suggestions for where to learn more about the use of brick bells specifically?

Thanks again!
Matt

Hi Matt;
No reason at all!   Batch boxes are Awesome!
Most new students of RMHs feel so overwhelmed with information. That they choose to start slowly, by building with bricks only.  
J-Tube rockets are great stoves and anyone can build one fast and easily!
Batch boxes are fast and easy to build as well once you understand their construction.
The metal parts needed to build a batch box are daunting if you have no easy way to build them.
I started https://dragontechrmh.com/  to help supply those parts.
The best place to learn about bells (stratification chamber) is right here at Permies and at Peter Berg's site   https://batchrocket.eu/en/.
Not much to learn really.  Your batch box exhausts into a hollow containment, it can be brick or metal.
A metal bell requires mass added inside or around the outside.
A brick bell is its own mass.
The superheated air rises quickly to the top of the bell and starts to cool. That air is immediately replaced by hotter air from the riser.
The cooling air then sinks toward the bottom of the bell where it locates a way out... up your chimney!
The mass becomes saturated with heat and then slowly shares that warmth with you.
Bells do have size restrictions but within reason can be any shape that fits your space,

Thanks, Thomas!! This is very helpful...