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perma/offgrid/homestead expirement project #1 - FIRST RMH

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I live in a city in the midwest, I make about 35,000, married, have 2 kids, work 40 hrs a week, and spend 90% of my free time being a dad/ husband.
There has been a stirring in my soul to create and build sustainable stuff. My dream would be to have an Earthship inspired home, and have all the time in the world to build it.

Someday I may get there. I know my wife wants to go back to school and we have some baby raising to do...BUT  I Cant wait!!!
SO... I've started dreaming up an RMH to put in my basement. I have some ideas about how it could supplement heating my house (i have a standard gas furnace) and it feels cheap and "easy" enough to do with my budget and time. I don't own a truck :( - and not living in the country makes finding certain cheap materials tricky. (plus i have little time)

I am creating this forum to post photos and update on my RMH so that I can get feedback throughout the project. Any comments and suggestions are welcome.

Thinking 6" system. I will be using Matt Walkers "poured" design , kinda.   [youtube]https://www.youtube.com/watch?v=7ANMXGrxgnEI[/youtube]  
would love some feed back. Here are my plans/ ideas.  

I would build both interior and exterior "mold" out of wood. I would build them With a larger interior diameter and add fire brick to the inside after build. I would use some kind of mortar/ slip to hold firebricks in place.

i want to use 1 Barrel for the build, and I want it to function as barrel and Manifold. This means my riser will be shorter than standard build. I have no problem shortening feed tube. I'm going to be cutting all of my own wood. Is there any other issues with making these aspects shorter? I understand it may decrease overall heat production, but as long as it will burn up all creasote etc, I'm fine with it.

I will be building this in the basement, under wood floor. I was thinking of doing some metal heat shielding. I will have to show pictures eventually, but does anyone see issues with this?


Posts: 698
Location: SoCal USA
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Hi Ted, I would highly recommend reading the Rocket Mass Heater Builders Guide by Erica and Ernie Wisner. There's been years of trial and error done by lots of people, and that book has a lot of distilled wisdom in it as a result.

As you may already know, a lot of the heat provided by a RMH is via conduction and radiation, so unless you are going to be in the basement with the RMH you might not benefit much from running it. You'll want to thermally isolate the mass from a basement slab, which will draw your stored heat down into the earth where you don't get to use it. There is a ratio of feed tube, burn tunnel, and heat riser that provides the most reliable draw, so if you can avoid reducing the heat riser you'll probably get the best results.

This house at Cob Cottage has a RMH in the downstairs living room that has a very low wooden ceiling (floor for the loft above) that I don't think I was able to stand upright in at 6'6" when I was there. They made a heat shield out of metal can lids that was suspended maybe 6-12" below the ceiling, and maybe 2 feet above the barrel. So you can do the same with a normal/full sized barrel, to help deflect heat if your space is large enough. I can't say their working setup means your setup would also work of course.

I totally understand your desire to do something now though. I personally have felt stuck in a setting where I wasn't able to pursue different ideas like permaculture/natural building, so being able to do something to scratch that itch is important. If you don't get to explore those ideas they either frustrate you endlessly or worse, you give up on your hopes and settle for something less happy.

So since you can make something affordably and give it a try first outdoors (always experiment/learn by building outside!!!) to see how it works and learn the odds and ends, then you can look at doing it inside if you can safely and properly vent the exhaust. I highly recommend you try making a simple gazebo-like back yard rain shelter that you can build the RMH under. You can experiment with it until you are happy with the layout and then cob it in if you like, and live with it for a while. Then I would suggest either taking it apart and rebuilding it inside, or if you can get another cheap/free barrel and bricks you can build a second indoors. But be aware if you make your first one indoors in the basement without outstanding ventilation, and it is leaky and you don't have a way to test for exhaust gases other than by smell, that could be risky in my opinion.
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Location: Upstate NY, zone 5
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Yes, definitely get a carbon monoxide detector for the space where you are building the RMH.

You need to be able to remove the barrel periodically for inspection, so I don't think a single barrel will work well. Making a cob or brick manifold if you can't find a second barrel would be easy enough.
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Best advice has been shared by Glenn!

Get a couple of carbon monoxide detectors in the rooms where you have RMH.
Hey, sticks and stones baby. And maybe a wee mention of my stuff:
Rocket Mass Heater Manual - now free for a while
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