Ok guys some advice needed, the rocket mass heater is in place (minus the mass) but something's not quite right (apart from leaking here and there) we burned for 1 hour and while it all heated up nicely (and made a cup of tea) we had smoke coming out the whole time, so it didn't burn the gasses in the barrel as it's supposed to. I've stayed pretty close to E&E's 6" design: It's a 23" tunnel (5" x 6" w by h)to a 47" heat riser (5.5" by 5.5"), with 1.5" gap to a 45 gallon barrel, the flue is 6" and runs 10meters. Now is the time to make any adjustments before the cob goes on.
You can see the layout here... https://www.dropbox.com/s/b00io5x8xf8lggl/Video%2002-10-2015%2016%2000%2018.mov?dl=0
You may need to try this solution to see if it's a problem with cross sectional area at some point:
allen lumley wrote: Hugo D. & ''th' Permies Cloud'' : I am sorry, but somehow the WAY that the numbers translated seem funky, could you repeat them for us war-mongering imperialists
who never learned the right way ?
Having learned the the hard way, if your whole outdoors lay-out does not work for you, immediately come off of the transitional area with a vertical chimney at least 6'
above any obstruction/high point outdoors and try it again ! If it works, fine the 'problem is in the Thermal Mass, it may only need more drying, or it may have too many
elbows as built.
If it does not flow well with a Vertical chimney immediately off of the Transitional Area, then you do not have your cross sectional area figured right,
or you have a problem in flow within your Transitional area, a very common area for trouble, this is an area for 3Xs the Cross Sectional Area and sweeping curves with
very smooth side walls, think sheetrock !
10 meters (33' +-) is approaching maximum length for a 6" system, and adding 10' for two 90 degree bends makes it overtaxed by a bit. With no chimney to help draft, I think that J-tube is doing a creditable job. A good chimney will get it roaring. Keep the chimney inside the heated space as far as possible for best effectiveness.
Thanks everyone, I've tested it today having angled the last 2 meters at 45 degrees up, with a noticeable improvement. Sealing the barrel down also seemed to help.
I'm thinking to put 2 meters at 45 degrees, and then a final 1 meter outside vertically (which would take it above the roof), while keeping most of this rise inside the heated area.
Going straight up would not be ideal here but I'll leave that final section uncobbed so it will be easy enough to change if it proves necessary.