The Combo Unit

Hi!

I have been looking at building cob ovens /rocket stoves / RMH for a while. I have been unable to do so, but this year is my big shot at it.

I am, however, going to be on a rental piece of land. I am not going to be able to have a bunch of trial structures dotted all over the place.

I have been pondering combining all the things I want to try into one unit, and I wonder if I could get ideas from others.

I'd like a cob oven, but I want to use a rocket stove for the heat, rather than building a fire inside and scraping the coals away. Mind you, this is strictly because I want to practice building these things ASAP, so the more I can put in one thing, the better - IF it will be useful and function well.

The thing is, I also wanted to have several other features in combination with this. I may be thinking too big - I often do.

Is it possible to have a rocket oven that also has a mass output which I can utilize to heat a greenhouse. I would like to embed a greenhouse frame into the cob structure. The frame can be enclosed in the winter for a greenhouse, and in the summer have a shade cloth and the mass would be used as seating, rather than greenhouse warming areas.

I am actually thinking of doing one in miniature just to see if all the elements can be combined efficiently so that when I am in a permanent location I can build one that is the size I need.

What do you think? Has anyone been able to combine all of these elements? - baking, rocket stove, copper tube hot water, mass heater for greenhouse, seating, all mostly out of cob.

Thanks much!

Hi Natalie! I also have the same problem of thinking too big when it comes to things. Over the years I have come to accept the fact that most things are the way they are! From your post it sounds like you have never built a RMH. If this is the case, you should go to webpage and purchase the book by Ianto Evans. Its available in PDF dowlad as well. THis will give you all the info you need to make a successful RMH from the ground up.

Combining all of those elements into a RMH, for a first timebuild, is going to be problematic. Not to say it cannot be done but with so many variables you will really need to understand the principles that make a RMH work.

Please be aware that attempting to heat water with a RMH can be very very dangerous. In fact the mods of this forum recently released a 4 DVD covering all of the aspects of a RMH and then some. 1 entire DVD out of the 4 DVD set is called "boom squish" and is specifically rocket hot water. They are also available for purchase/rental on the site listed above.

Dont be discouraged by any of my comments If you are willing to put in the time you can most certainly get what you want.

Thanks, Amos!

No, not discouraged at all.

Correct, I've not had the chance to build one yet.
But I do have the book you mentioned.
I've been looking at videos and reading web pages for years.
You'd think after all that, it would be simple for such a seemingly simple tool.
However, it's one of those things that is so different than all we've been used to, that it's hard to get the mind around it and not be overly-concerned about blowing yourself up. LOL

That's why I want to get in some practice ASAP.

I think I've read enough and if I don't get my hands in there, I'm not going to progress much more.
I'd love a local workshop, but this really isn't the area for one to occur, I don't think.

You say the copper tubing wound around the bread oven cob has proven to be dangerous or give unhealthy water?
Or are you referring to something else?
This is just having a copper tube embedded into the final insulating layer of the cob oven and wound downward in a loose spiral. You leave a bit poking out at the top and a little spout sticking out at the bottom. While the oven is hot, you can pour water in the top, and it comes out hot at the bottom.

Good to hear! You are right. Hands on experience is what you need to put all of those years of reasearch to work!

Heating water with a RMH has the potential to be dangerous. There are safe ways to do it. There are solutions for heating water with RMHs in the wild but most of them are tailored to a specific application. ie hot showers, washing clothes, potable cooking water, etc. As far as I know there is not a one size fits all application that is out there. Since you have been doing research for some time now, are aware of the potential risks involved in using a RHM to heat water. I only mention the safety aspects of attempting such a feat for others who may happen upon this thread with limited experience.

Your proposed hot water design: I like that it is manually operated and more of a hot water on demand scenario as opposed to using pumps or a reservoir to keep a large amount on hand. However, if you think of boiling a pot of cold water on a stove top, you now have an idea of how long it takes x amount of water to heat up to desired temperature. Now think of pouring cold water through a coil of copper wrapped around a warm layer of cob. Unless the coil is really really long and the layer of cob is really hot the water wont have the chance to heat up much.

It might seem foolish to mention but, based on your description, if you are only after small batches of hot water, a few kettles in rotation or a large soup pot might work out just fine

I mentioned copper pipe, in another thread, in relation to not being safe in an aquaponics system and did not refer to drinking water.

You got me.

I want the instant water thing for the coolness factor. LOL
I think that is the niftiest idea!

Here is where I saw it. That feature is about 13 minutes into the video.


I love the seating area, the instant hot water, no muss, no fuss, the cob oven...
I just need to add the rocket stove and greenhouse part.