Our House

RMH with permit - installed in the Dana Annex

One of the points of discussion at the rocket mass heater workshop was how to get RMHs permitted by local government.  RMHs aren’t a wood stove, they aren’t a masonry stove and unless you’re a RMH aficionado, which city and county permitting departments generally aren’t, getting a permit to get one built and approved is a fairly steep road.

Ernie Wisner and Erica Ritter have been working toward getting the basic RMH tested and approved.  They were able to get a permit for the RMH installation in the Dana Annex but the county/city hasn’t yet signed off on it.

To get the rocket mass heater design approved, emissions need to be certified by an accredited lab.  With the stove technology certified, the permitting process for all of us becomes much easier.  We need to get this technology transitioned from *experimental* to tested, something all of us who want to install a RMH need.

Toward that end, I have seeded a fund for testing and certifying the rocket mass heater but funding the project is something I can’t do this alone.  I need your help.  If you are an alternative building person, you understand how important it is to get the technology we advocate recognized and approved.  It’s we, the little people, who are going to make this happen.  If you think RMHs are fascinating, contribute and be part of the development of this technology.

If you can squeeze some money out for this project, be assured it will be used wisely.  Donations earmarked for Testing Fees will be used specifically for the costs associated with certification using an EPA-certified lab or university.  Certification gets us a big step toward an accepted permitting process.

Donations specified for use in general research will be used for the purchase of refractory materials, water-heating parts and other materials needed to develop test builds.  This is research from which we will all benefit.

PayPal your donation to eawisner@gmail.com.  When you donate, designate whether you want your funds to be used for RESEARCH or TESTING FEES.  Please help me support this worthy project.

In planning my rocket mass heater installation, I’ve got some challenges.  The firebox is outside, the radiating tank is inside, half the thermal mass is inside, half is outside (sun porch).  And according to what I’ve been reading, every 90 degree elbow is equivalent to 10 feet of straight duct.  Ouch.

I’m planning a 7″ system because I’m planning to use 8″x6″ rectangular steel tubing for my riser.  That cross sectional area translates closest to 7″ round pipe.  Because I have to have some of the thermal mass inside and some in the sun porch, I will have to calculate my turns carefully to ensure I don’t add so much equivalent length I slow the flow excessively.

Wadly and I have been thinking through different methods for breaking EPS foam scraps down into the beads the blocks were made of.   I’ve seen and heard of all sorts of different methods being employed.  One guy used his weed wacker inside the bag.  Another stacked about 100 skill saw blades onto a shaft and used that.  Another has some sort of shredder (undefined).

We may have hit on a method that will be easy, cheap and effective.  We’re going to roll barbed wire onto a metal tube, add end caps and a rod down the center, a large fly wheel to slow it way down and we’ll run it using the motor from the cement mixer.

Since the RMH workshop I’ve been tossing around ideas for my installation.  With rocket mass heaters, the devil really is in the details.  They’re super inexpensive to build if you can scrounge the parts and innovation is rampant and lauded IF it works.

The mock-up of my stove encourages me to find a larger diameter riser.  The 6″ well casing I have will work, but bigger in my case may be the difference between marginally functional and awesomely functional.  Ernie’s suggesting an 8″ core and I’m agreeing . . . bigger in this case is better as long as I don’t go above 8″.

I put a “want” out for 8″ well casing on our local freecycle and our County’s 2Good2Toss.  I’m not really expecting any results but I have to try.  I probably shouldn’t be fussing about this as the installation isn’t going to be a long term one.  I could use 8″ stove pipe.  It’s certainly more readily available, would easily last the couple years I need it to and I know where the scrap pile is for our local stove store.  But you know me, I’ve always got to say “what if”.

Logging is big in our area.  Short lengths of log truck reach (3/16″ thick 8″x6″ tubing) are pretty readily available.  With Wadly’s connections I could probably score 50+ inches of that fairly easily.  So the question is, can I use 8″x6″ steel tubing for the riser?  What effect will the rectangular shape have on the draw/draft?  I’ve posted queries on the RMH Experimenter’s Corner and and on the Permies Alternative Energy forum.  I won’t hold my breath waiting for answers.

Riser in place and base for barrel in the works Working through the exhaust port detail Mocked up exhaust port Making sure the barrel is properly supported With barrel added and fire started Nice clean burn, good draft Without an insulated riser, once the barrel warmed up, draft was lost and smoke-back was unfixable Knocked apart when the test was over

Last weekend I attended a rocket mass heater workshop put on by Ernie Wisner and Erica Ritter.  I learned SO much!  You cannot imagine!  I’m going to try and cover a very small portion of what I learned.

I learned I will not be able to use all the lovely free stainless steel ducting in the construction of my rocket mass heater.  Some I will re-purpose to improve air circulation between rooms.  Whatever I have left won’t go to waste.  You know me, I’ll find a use for it.

I spent the night at Ernie and Erica’s on the RMH bench in their living room.  My hips loved the heat.

My RMH requirements are a bit out of the norm, so I took my parts with me to do a bit of testing to see where I would have issues.  The whole process was extremely educational.  The pics on the left are thumbnails.  You’ll need to click the thumbnail to see the detail.

In addition to the four paying attendees was an awesome and ever changing group of young people known collectively as “the legs”.  You will see bits of them in the photos of my rocket mass heater test.

I’ll post more later.

We got the second window in the south wall of the sun porch today.  It looks awesome!  Okay, it looks as awesome as dirty windows can look!  <grin>  Neither of the windows are permanently fastened in yet and the divider between the windows hasn’t yet been installed but it’s still progress!

Terry and I got the sun porch roof finished. It’s AWESOME. We’ve got one glass panel in the south wall and one to go.  We’ll keep pecking away as weather permits.

I still have to figure out what I’m going to do with the north wall. I wanted to use eps-crete, but finding a way to grind the foam is proving to be problematic. I’m going to talk to Lorr (son) when he comes today to see if he is willing to fabricate something. I don’t see it being complicated. We’ll see what he says.

If I use papercrete, I’m going to have to parge (word is NOT in my dictionary!) the sun porch side to keep it from absorbing moisture AND I’m going to have to build a retaining wall (also on the sun porch side) where the wall has to be backfilled.  I really want eps-crete for the wall.