Dave Patty

I've got a 7" x 7" x 24" ceramic flue liner that I am planning on using for the center of the heat riser.  Have got a fairly heavy gauge (1/8") water heater tank that I am gonna cut top and bottom off of to use for the outside of the heat riser.  Was thinking of using a sand/clay mix at the base to seal and then filling with sifted and packed ash and toping with more of the sand/clay mix.

If money wasn't quite as tight right now I would go with the perlite but... 

Does this sound like a viable plan?

If not I do have some SS 6" triple wall that I can tear out of another building but would rather not if the ceramic would work.

Thanks,
Dave

The only way I can see the flow reversing is if the outside outlet of the exhaust flue were to slope downward which would seem to be a bad thing in trying to get rid of even marginally warmer than outside temp exhaust gases.

Not saying that running the exhaust under/in the thermal umbrella isn't a good thing/idea, just not sure about using the exhaust flue to bring warmed outside air back into the dwelling. 

Now if you were to add an earth tube (? I think this is the proper terminology but please correct me if I am wrong.) in the trench below or beside, but separated by 6 inches, or preferably more, of dirt/rock/thermal mass, from the exhaust flue, when burying it, to use for warming outside air and bringing it back in I think that would work.  Again in the case of the earth tube, the outside air inlet would need to be lower than the inside air outlet for proper flow to take place without the use of a fan or some other assist.  And you would also be able to have fresh air coming in while using the RMH.

Dave

Thanks for the welcome!  I'm about 70 miles south east of you outside of Weaver, Al.  Seems like I have seen barrels for sale in Sneed or somewhere up that way.  May have been going into Cullman.  We sell at trade days and flea markets and get up that way from time to time.  Used to be someone at Mountain Top that handled barrels and steel but I don't remember seeing any in a while.  There's a trailer place on 77 just south of Ohatchee that sells them but don't know how much they charge and that's a ways from you too.

I'm gonna try to mock one up tomorrow out back and see what all I'll need to get.  Think I have everything but the perlite/insulation, just have to round it up. 

Quick question.  Has anyone tried using ash for the heat riser insulation?  Not meaning to hijack your thread, just thought I'd ask.

Later,
Dave

Carryion, 

Whereabouts in N. Alabama are you?  I'm in East Central Alabama and there are a number of places around here that are selling good used 55 gallon barrels in the $20 to $35 range.

And yea, the average low temps around here are 30 to 40, but we've been seeing some low to mid teens the last few days.  Was 13.3 F here 2 nights ago and I suspect it will be lower tonight.  That's the main reason I got to looking at the Rocket Stove Mass Heaters and found this forum.  We heat with wood and I'm tired (in both senses of the word) of getting up every 2 hours to feed the Ashley woodburner and still being cold.

Dave