Slowzuki wrote "no coals"
I am not sure if it is the case with all of the downdraft gasifiers (where the wood in the upper chamber collapses into coals above a "nozzle"), but with my Econoburn, I do find that being able to generate and maintain a bed of coals seems to make a major difference in both duration and efficiency of a burn. While I do not have instrumentation, when I look at BTU charts for heat content of different species of wood, and then note the "effective heat" that I get out of a full firebox full of different species, the disparities are even bigger than the chart would indicate. From all I've read (and it makes sense to me) BTU content in concept/ under lab conditions tracks the net dry weight of the wood, but using the combustion technology that I am using, it seems like woods that develop a substantial and sustained bed of coals (maple, yellow birch, hophornbeam) yield an output (both intensity and duration) that is almost 3:1 compared to woods (poplar, pine) that don't- even though the data suggest that it should be more around 2:1.
I am not sure if it is the case with all of the downdraft gasifiers (where the wood in the upper chamber collapses into coals above a "nozzle"), but with my Econoburn, I do find that being able to generate and maintain a bed of coals seems to make a major difference in both duration and efficiency of a burn. While I do not have instrumentation, when I look at BTU charts for heat content of different species of wood, and then note the "effective heat" that I get out of a full firebox full of different species, the disparities are even bigger than the chart would indicate. From all I've read (and it makes sense to me) BTU content in concept/ under lab conditions tracks the net dry weight of the wood, but using the combustion technology that I am using, it seems like woods that develop a substantial and sustained bed of coals (maple, yellow birch, hophornbeam) yield an output (both intensity and duration) that is almost 3:1 compared to woods (poplar, pine) that don't- even though the data suggest that it should be more around 2:1.
! Lots and lots of limbs. They are also not a hardy tree at all as they get weak spots and break. I have some pictures of some of the trees we left just to show you some of the mess you might get with these things. Also, the rate of growth my be right in perfect soil but we were told we had ideal soil for these trees and it took between 15-20 years before any got to any size that we would have considered for firewood. We have only a few left that are growing from some stumps but we cut the last of the big trees when we sold our pines last winter. Good riddance to bad rubbish.
