So the heating season is coming to an end and I actually stopped running the heater for the most part. I have learned a ton with this first build. Recently I have filled my house with smoke twice and that was enough for me to quit for now on this current stove. I think it smoked back because temps were a little warm outside, not real warm but just enough to cause draft problems. I didn't incorporate a cleanout in my stove pipe so for me to prime the stove pipe I have to take the barrel lid off and light a paper in the bottom of the barrel where the pipe exits. Its a huge pain in the butt so that's gonna need to be incorporated in the next build.
Second thing i learned is everyone who said basement is a bad idea for a rocket mass heater is absolutely CORRECT! I just needed to find out for myself. For the past winter I have been running up and down my basement stairs about 15 times a night to reload and shuffle shake down the burning wood. I expected a couple trips up and down the stairs but not that many.
Next is my upstairs was around 70-74 degrees every night, after burning for about 5-6 hours. This is the real reason that basement location is a bad idea. The entire basement needs to heat up before the heat travels upstairs. I had a wood stove before I build this stove and the heat came upstairs way faster, that's because the rocket mass heater needs to build its heat first then it can spread around the house. So needless to say, i tried to spend all my time in the basement for easy refilling and staying warm!
Next problem was my feed tube. I mortared the entire heater together with just fire clay alone. This stuff is very fragile. A few weeks into running the heater, I noticed sand was falling through cracks in the feed tube area between the firebricks meaning my clay mortar is cracking and failing. I have the entire jtube surrounded by perlite and then on top of the perlite is sand. That's the sand that's filling into my burn tunnel. This is my first time mortaring with fire clay and I didn't know it would be that fragile. Now I know.
Another problem I had to combat is the fire climbing out of the feed port. This could be caused by a couple things. I used thicker splits than I believe I should have been using, causing them to not crumble down to coal as fast as I would have liked. This left more time for the fire to climb up the sticks. Also, I think if my feed tube was a little smaller the faster air flow might have kept flames down a little better. My fix was to bend a piece of sheet metal into a square and basically raise my feed port about 10'' higher to be taller than my sticks I was burning. Then I placed another piece of sheet metal over the top of the square to allow about 25% of the surface area of air flow in. That way if the sticks did flame up then the fire was still surrounded by more feed tube.
And the blue tarp and tiles under the stove are no problem at all. Under the burn tunnel, I laid a piece of ceramic fiber blanket on top of some plain bricks and build on top of that. It seems like a VERY effective insulation keeping everything cool enough to not transfer heat where I didn't want it.
So now whats next? Build a new one upstairs in my living room. There currently is no stove pipe in my living room so I will have to install that this summer. I want to do a build similar to the dragon heater castle builds out of the clay flue tiles. I will ad a cleanout t so that I can pre heat the stove pipe much easier. If I build one in my upstairs, my living area will be toasty within 2 hours I assume. My basement would go from 59-60 to 70s within an hour and a half with my current heater.
Now hears my innovative thought. I want to make a cross between j-tube and batch stove. That's almost what I had once I raised my feed tube with the sheet metal.
Is it possible to make a regular j tube stove then make a little bell that goes over the feed tube like a can or something the right size for the feed tube, and add a couple air ports for the secondary combustion? Here's what I think will happen. The sticks in the feed tube will obviously climb the sticks but the air port will be at a point that is proportionate to the system, not at the top of the feed tube. This way the draft wont want to run backwards because the feed tube air flow will be low enough that it still drafts correctly. This way its almost like a batch j tube. The flames would be going on in the feed port and the gasses would get sucked into the burn tunnel where more air is mixed in for a clean burn.
Does anyone have any experience doing this mod to a regular j tube?
I hope my wording is clear enough to get the ideas across.