Large Rocket Mass Heaters

Salut Permies,

I began designing a ~500m² commune farmhouse for the Northern German climate (comparable to Massachussetts). It is buried except for a glass wall to the South (the Earthship method), has large buffer greenhouses, lots of solar thermal storage, and should thus be able to stay above ~55 degrees naturally.

There are a number of tasks for a rocket mass heater to do. An oven, seven hot plates, a samowar, a drying chamber, two cob benches and a part of the floor all need heat of different intensity. For a few weeks in winter, it would also be needed for heating the whole house by five, six degrees. Not more.

Ianto's book does not take the technique to this size (yet). My question is whether you know of experiments with larger (12"+) systems. Experience with broad underfloor heating would also be very helpful.

I sincerely hope the technique can be upscaled some time in the next years. We can, of course, build two systems in case there are inherent problems.

Wishing a beautiful spring,
Louis

kiwiza wrote:
There are a number of tasks for a rocket mass heater to do. An oven, seven hot plates, a samowar, a drying chamber, two cob benches and a part of the floor all need heat of different intensity. For a few weeks in winter, it would also be needed for heating the whole house by five, six degrees. Not more.

It sounds like what you really want is a "Krestianskaya Teplushka" ( http://www.pyromasse.ca/articles/75kmwest_e.html ). Some of the varients do all or most of those things. The forte of the RMH is to burn a small bit of wood vary quick and completely without dumping it into the room too quick. It is very good at that. However, you want to expand a huge amount on that... it could be done, however, you would end up using a lot of the things shown in the article above anyway. Also, if permits are a concern, that would effect your choice too.... and the cost. You could still use cob at least for facing, but maybe for some of the lower temperature smoke paths as well. You may be able to use rocket firebox to feed it, but I don't know if it would gain you that much. The article above shows a separate cooktop which you probably need if you are cooking for many people. I have seen others where the cooktop was right in front of the oven run from the same firebox as the oven (the firebox being in the opposite corner to the one in the article). These were originally built by the peasants who used them, often out of bricks they made from the soil on the land. So it is doable.

Merci. Will read through later tonight. I do not think about permits at this stage. It is always good to be reminded about them, it is good that you're doing that.