Rocket mass heater on a skoolie?

Hello All,
I am wondering if anyone has considered or has attempted a rocket mass heater in a tiny home/RV/skoolie. I am located in Northern New York and will have a cold winter! I played around with a tent stove in my skoolie and enjoyed the smell of campfire while being heated this past winter. I lived in an apartment and spent time in my skoolie on my raw land when I could. Not sure if my skoolie will become an accessory dwelling as it is currently off the road and semi permanent. It is road worthy with a tune-up. The woodstove I used was a Winnerwell Nomad intended for my Springbar tent. I used it in the skoolie and piped the smoke out through an open bus window. I need to create a more efficient and "breathe safe" option as I would like to use the bus as a dwelling for this fall and possibly the winter. When I purchased the bus it already had bench seat/storage area that I think would make a great frame for a mass heater. I am afraid of too much smoke or creating a fire hazard. I have a lil one and safety is a priority! Any suggestions?

CHEERS!-
Brit

Brittney:  The first thing that comes to mind is a 55 gal all in the barrel RMH.  Called the cottage rocket.

https://permies.com/t/150536/Uncle-Mud-CottageRocket-Paper. << Design by Uncle Mud

A Built unit by Peter van den berg the minnie mouse
  I like this as it reminds me of the "tile stoves" in Europe.  

You maybe interested in this thread on Peter.
https://permies.com/u/152487/Peter-van-den-Berg


And the original gravel rocket of paul's design is  light (for a rmh)  and transportable, especially if you take it apart and ship the gravel in 5g buckets, by bicycle!


The build thread on permies. "portable rocket mass heater". Lots of info as they learned it.
https://permies.com/t/80/2558/portable-rocket-mass-heater

Example:  see why I think it would fit in a schooli?
https://permies.com/t/30925/Pebble-Mass-RMH
 

A place to start.  Tom

Thank you...so many ideas! I'm already starting to sort my hearth rock collection!

Personally, I would build an RMH underneath with a thermal break to insulate it from the soil. Park the bus over top, and add side skirts to block the wind. Warm floors make for happy winters!

Brittany Marks wrote:Hello All,
The woodstove I used was a Winnerwell Nomad intended for my Springbar tent. I used it in the skoolie and piped the smoke out through an open bus window. I need to create a more efficient and "breathe safe" option as I would like to use the bus as a dwelling for this fall and possibly the winter.     Brit

IF you haven't yet built a RMH for your bus a good alternative at reasonably low expense is to obtain some heating fins for your smoke stack and install them. They will take up some space, however 2-4 fins around that pipe should pull out a lot more heat INSIDE the bus rather than have it go outside. It might be worth a try!

You've already got some good ideas here. The big issue seems to be the mass-iveness of the mass it self. Some ideas for that:

* Just do a rocket heater. Do everything you can to reflect that heat into the space to warm up the objects in the space.

* Of course, pennies of insulation is worth a pounds of mass... But you're in a buss... I don't know, is it possible to blow in insulation between panels of vehicles to up the R factor? Do people do that? It would making chasing wires a painus in the future, but it would make it warmer... Also, if my science is right (and I haven't checked with Fauchi, so I don't know for sure) radiant heat is just light... IR I believe...  I think that reflects off glass and stays in the rig... the idea here is to think about what wavelengths are leaving the bus (is it buss or bus... my grammar may be wrong but I think my science is right). So consider your three types of heat transfer - Conduction, Convection, Radiation, figure out which is most important, then optimize trade-offs. Maybe simply having roll-down window shades would dramatically retain more radiant heat and help to reduce convection over the windows... Maybe you're willing to do flip down insulated flaps... maybe a blanket over windows...

* If the mass has gotta be inside the buss...  Maybe you make the mass a large amount of water. OBVIOUSLY, you will do your due diligence and put in check valves... let's assume you're not an idiot and the system is safe... (and as soon as i post this, people who know nothing about steam will assume that any amount of warm water will explode... brace for comments...) Hear me out. Water would have lots of advantages. It means the mass can be anywhere, and any shape if you can safely move the water around. So that could be an insulated hot pipe that goes under the seats to reservoir(s)... You can drain it and drive away, there goes the mass part. Would be pretty cool to hook up a solar hot water heater to the same volume of water... could warm you a little for free in the sunny hours, taking in more heat when the RMH is on... maybe even use the hot water for practical things, like warm showers or washing dishes... Maybe you don't design the water part yourself... there's plenty of information out there, even finished boilers that can be obtained, with all the expertise and safeties that go with them. If you go with water, make sure you know how full it is before every use: you don't want super-heated steam finding holes into your small living space... Everyone's going to freak out at this suggestion to use water, but we've been using steam power for centuries. Even nuclear is a fancy way to make water hot. You're not even after steam you just want warm... So oversize...

* If you're not moving around a lot, modular mass might be enough. Consider bricks, pavers... any mass you can easily handle. The less expensive the better, maybe even expendable if you move on. Gravel may work, but it's less dense and has a lottttt of air pockets.... Also very hard to move around, makes a mess... not ideal. Consider staggering flat pavers to reduce the airflow between the pavers. The flatter the faces the better: less air = less air movement. Maybe you have some pieces that fit snugly over the pipe, to translate pipe shape into the standard paver size you have. Cob seems ideal... other stuff may work. Consult the oracle RMH builder's guide on permies... Yeah, so cobb (whatever) around your pipeing zones that you want to pull off heat, that should fill whatever awkward space allows you to then stack close bricks/pavers... (That would reduce the permanent mass, and make most of it modular.)

Whatever you do, be sure you're maintaining clean air in the small space. Manage fire exhaust AND make sure the fire isn't depleting all your O2. Redundant audible alarms should do the trick, if placed at the right locations/elevations. A heat exchanger wouldn't be a bad idea, little counter productive, but a good stupid-simple safeguard to make sure you'll always have another lung-full of O2. In a small space with a fire, I'd give my left lung to KNOW that my right lung would always have O2... of course, you could always draw outside air for the combustion, and that would help with the O2, but you'd have to trust your exhaust is sealed to protect from gas buildup. So outside air and sensors for carbon monoxide etc.

I will be building a DSR2 inside my 1989 Blue Bird Bushop. I went with the DSR2 as I knew that there would be some serious height constraints inside of the bus. So far I've only mocked up the heater, but it did fit into the space very well. The other reason I really liked the idea of the DSR2 was that it has a black oven, so why not bake bread or cook food while heating up my shop.