Kjartan Rumpsfeld

Creighton Samuiels wrote:

Kjartan Rumpsfeld wrote:I see this is a pretty old post, but it hits what i am looking for so ill make an attempt to write my thoughts out here.

I currently live in Norway (Northern Norway) and my father wants me to build a rocket mass heater outdoors and build a pizzaoven on top of the barrel (my hopes where that the heat from the barrel would preheat the oven to a resenable temp before i would fire it internally)

Why don't you incorporate the pizza oven into the riser (barrel) itself?

I do have some cool materials availible to me, (i don't think cob/clay would be easily availible, but i might be wrong) There is clay in the shore, but this is seawater so i don't know how this is for building, also there will be no roof over the RMH and my thought was to use Slate, i think its called slate, as a finish and some special stone to hold the heat, my thought was to start off with a layer of foam insulation, then some sand, then the exaust pipes on top of this, and then perlite or something else that holds heat, a layer of the specialty stone that is designed to hold heat and then the layer of slate as a finish on top, so maybe a gap of about 10-12 inches from the top of the exaust pipe to the top of the finish.

I'd consider the foam to be risky. If it gets hot enough, it'd lose it's ability to support the weight.

Does this sound like a workable ide (i almost wrote good idea... but i left that one out:)

ALso had the thought of insulating the barrel so that i could build the exaust longer and so that more heat would get up into the pizzaoven on top and through the exaus (building a longer bench), so would this work? to inslutate the burnbarrel?

It's generally a bad idea to insulate the barrel, because part of it's function is as a radiator. It permits the hot gasses that have just existed the internal riser/chimney to cool somewhat, becoming heavier and thus contributing to the difference in density that pushes the exhaust gases the rest of the way through the horizontal mass channels. It's important to how the RMH can work without a normal chimney, which wouldn't work anyway with the cool exhaust at the end of the mass channels. If you were to install a pizza oven at the top of the riser, presumedly with a bottom baffle/reflector/fireback or two to prevent the very hot gasses from direct contact with your pizza, the external surfaces of your pizza oven could serve the same function, replacing the barrel altogether. You'd need to make it out of exposed steel, however, which is contradictory to what tradition would suggest; since most ovens are built to keep heat in, while your's would have to be built to permit heat to escape.

You'd have to be selective about the species of wood you chose to run the RMH whenever you used the oven, since there might still be enough unburnt smoke to affect flavor.

Cool, thank you, i am not quite sure how i would incoorporate the oven instead of the barrel, the thought i am having right now is to build the oven on top of the barrel and leave half of the barrel exposed to the elements and to use the barrel and stones around parts of the barrel as support for the oven, my feel was that this would give a couple of 100 degrees farenheit as a startup making it easier to fire up the pizzaoven after a while, and still having the normal effect on the RMH with most of the barrel exposed.

Do you have any pictures or links to something like i am talking about?

Also, what do you think of a slate finish, instead of a cob finish?

My thought was also to use some soapstone as a layer above the exaust to hold heat for a while and to use Leca balls (don`t know if this exists anywhere else then here , but they are basically Burnt Clay balls that are puffed up so they hold quite a bit of air, and are used as insulators) would this be a good thermal mass to use? the way i am seeing it is that airgaps would hold quite a bit of heat and if there is a layer of soapstone covered with a layer of slate it would be a good surface that would hold heat for a while?

I would also use granite to build my "exterior walls" and then plaster slate on top of that, giving it a slate/tile finish.

what are your thoughts on this?

I see this is a pretty old post, but it hits what i am looking for so ill make an attempt to write my thoughts out here.

First off, i love this alternative building stuff, awesome!!

I currently live in Norway (Northern Norway) and my father wants me to build a rocket mass heater outdoors and build a pizzaoven on top of the barrel (my hopes where that the heat from the barrel would preheat the oven to a resenable temp before i would fire it internally)
I do have some cool materials availible to me, (i don't think cob/clay would be easily availible, but i might be wrong) There is clay in the shore, but this is seawater so i don't know how this is for building, also there will be no roof over the RMH and my thought was to use Slate, i think its called slate, as a finish and some special stone to hold the heat, my thought was to start off with a layer of foam insulation, then some sand, then the exaust pipes on top of this, and then perlite or something else that holds heat, a layer of the specialty stone that is designed to hold heat and then the layer of slate as a finish on top, so maybe a gap of about 10-12 inches from the top of the exaust pipe to the top of the finish.

Does this sound like a workable ide (i almost wrote good idea... but i left that one out:)

ALso had the thought of insulating the barrel so that i could build the exaust longer and so that more heat would get up into the pizzaoven on top and through the exaus (building a longer bench), so would this work? to inslutate the burnbarrel?

feel free to make any suggestions or ask questions, i will try to be more specific with the rock types that are here.

How does Leca Balls work as a thermal mass?

thank you guys

with love

KJ