Our House

I think we’re getting closer to spring.  I’ve got daffs up and my elephant garlic is poking through the dirt.  I’ve got quite a bit of pre-spring gardening to get done as weather permits.

Dan (brother) is still working on a foam grinder for me.  He’s not working so it might catch his attention a little more often and I might actually have something to play with by late spring.  As soon as I can grind some foam I’ll get the eps-crete infill installed in the north wall of the sun porch.  Once that’s done I can pour the last bit of footer and get the east wall glass put in.  Once that’s done I can get my fish tank moved in and my aquaponic grow wall (lettuce, tomatoes, peppers, et al grown in hydroton) put in place and start growing for our table.  Right now the fish tank is outside half sunk into the ground.  I can’t grow anything attached to it until the weather warms fairly dramatically unless I install a heater in the tank.  I can’t do that until I get the new electric service in (coming up soon!).  Getting the tank into the enclosed sun porch will greatly lengthen the growing season without increasing the electric bill.

It’s been so warm I haven’t been able to talk Wadly into installing the sawdust stove.  I keep hearing “next winter” when I mention it.  I know better than to push.  He pays the electric bill and collects the sawdust we’ll burn once the burner’s installed, so it’s best for me to just go with the flow.  When he’s ready, we’ll get it installed.  I’ll start pushing him mid to late summer so it’s done when the cold weather hits.

Judy of the woods do-it-yourself desk chair.

I occasionally do mad spates of research.  This morning I was trying to find a comfortable and supportive desk chair solution.  I spend hours at a time sitting at my desk and finding a chair that supports me properly is proving to be difficult.   That’s not the reason for this post.

In looking at desk chair images, I ran across the lovely image to the left.  This sort of thing makes me smile.  It’s an excellent example of someone thinking outside the box!

Judy’s chair struck a chord.  My current desk chair is being held in a relatively comfortable position by a length of cord, a cargo strap and a length of mountain tape (1″ wide flat nylon tube).  I’m not perfectly comfortable, the chair is still tipped a bit too far back, but I am *more* comfortable than I was before the cord, cargo strap and length of mountain tape.

The moral of this tale is, when we can get beyond vanity to cost effective function, we truly have come to the point where we can be thrifty and self-sufficient.  Judy of the woods looks to be a sister of my heart.  Check out her blog.  There’s a lot of interesting stuff there.

The day before yesterday Wadly and I test fired the sawdust stove out in the yard.  It really does work exactly as acclaimed.  We used fairly damp cedar sawdust (it’s what we had).  I had a little trouble getting it lighted (learning curve) but it burned just fine once it was lit.

Wadly’s planning to burn the paint off so it’s safe to light indoors.

You might want to check this out.  A person commenting on a previous post turned me onto a forum thread about a sawdust stove being used in a wood shop.  Thanks Nancy.

In future I hope to have dry hardwood sawdust to burn.  Keeping us supplied is going to be Wadly’s job.  Right now we have two stove loads of cedar sawdust.  That will do to get us started, but it won’t last beyond a day or two.

Note to self; learn how to braze and find your your anvil.

Raw sheet metal parts.

I took my concept for the bottom workings of the sawdust stove to our local sheet metal shop and they did a brilliant job of turning my concept into solid objects.  All this perfection (not the vent adapter which I got at Goodwill for $5) cost $89.  That’s a heck of a deal, in my mind.  I just don’t have the tools to easily cut and bend metal.

Yesterday I cut the hole for the sleeve/drawer in the 55 gallon drum.  The hole looks great.  It’s a tiny bit smaller than the final, but I’ll leave it as is until I talk to Lorr.  I’m dealing with a barrel that has a fairly good arch in the bottom, so want to have flexibility for which way I jump when putting this all together.

The hole in the sleeve (piece standing on end) has had its edges bent upward to facilitate centering and supporting the burn chamber.

All these bits (not the vent adapter) are to be tack welded Saturday at Lorr’s.  I’ll try and get good pics of the assembly process.

I haven’t cut the exhaust hole yet.  I don’t want to do that until I talk to Lorr.  He may not be okay with using the vent adapter.  Cutting the hole to match the vent adapter reduces my ability to step back and punt.

It’s going to be a while before I get the sun porch done and we can get our rocket mass heater built.  In the interim, I must have a less expensive (and quieter) way to stay warm.  Toward that end, I’ve been researching sawdust burners.  We can get sawdust free if we shovel it.

The premise of the sawdust burner is to use a low/no cost waste material to supply heat in a stove that can be hand built quickly, easily and inexpensively.  The plus for me is I can disassemble the stove and cart it outside for the summer months.  A 30 gallon barrel of sawdust should burn for about 8 hours.  With extra 30 gallon barrels pre-filled with sawdust I can quickly replace a spent barrel with a fully stocked one as needed and filling the barrels outside would keep a good part of the mess out of the house.

In one of my forays on the web I ran across a video of a sawdust burning heater built in England.  You can watch the video here.  The model in the video is available from British Hardwoods Online for about $500 US.  Shipping inside England is about $75 US.  In an attempt to get a real clear idea how the stove was built, I did some searching and, through chance, ran across an old open source plan for a “double-drum sawdust stove“.  The plans are available (free) online at VITA.  Do a search for double-drum sawdust stove and you should find the link.

The design shown in the video is a takeoff (improvement) of the original double-drum sawdust stove design. When comparing the plans to the video, take special note of the difference in location of the single exhaust exit from the outside barrel near the bottom, the lack of damper on the chimney (not needed or advised) and legs instead of a “false floor” in the outside barrel. The inside barrel’s three legs hold it above the ash drawer and allows air to circulate around inside the bottom of the outside barrel facilitating the exhaust up the chimney.

These relatively simple changes improve the performance of the design over the original.  With parts and self-labor, this stove, with the aforementioned design changes, can be built for about $100 US.  As we build I’ll keep close account of what we spend as opposed to what we can salvage so I can share the result at the end.

Wadly is embracing the task of accumulating the necessary 55 gallon and 30 gallon drums.  I will acquire the stove pipe, sheet metal, metal drawer pulls, adhesive and gasket material.  In addition I’ll need to buy a 45° and two 90° elbows.

Rather than weld legs on the barrels, I’m going to use three fire bricks to hold the inside barrel off the bottom of the outside drum.  I’ll buy (hopefully used) stainless drawer pulls for the handles on the lid and drawer.  If I can’t find the pulls I want I’ll build some out of 3/8 mild steel rod.  I’ll fold, spindle and mutilate a piece of sheet metal for the drawer and I’ll use the cut-out piece as part of the vent control on the drawer face. I’m a bit fuzzy on this part, but I’ll get there.

I want to be able to install temporary fire proof wall covers for the corner where the burner will rest.  I’ve got plenty of fire brick to make a base on which to set the burner.  I can mortar them in with a clay/sand mortar which will make them easy to take apart and clean for reuse or I can build a 2×4 fence and set them in place therein.

I’ll supply pics as we build/test/build/test so you can see what works and what doesn’t.

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!