Lightning wrote: ↑Sun. Jan. 07, 2018 12:06 pm
Wow, those are some startling numbers Larry and pretty solid conclusions too. I wonder if split wood would be any better or worse than the fuel blocks.
Nice work!
Edit - Is DHW factored into that, or doesn't it need to be?
I used HDD's and my computer spreadsheet accounts for DHW demand, so it is factored in.
I assumed 7,825 BTU per pound for the compressed sawdust wood blocks based on only 6 to 8 percent moisture. Well seasoned hardwood delivers (for the absolutely best case scenario of only 20% moisture) 6,750 BTU's per pound (and real world it is highly likely to be less, call it 6,250 BTU/Lb.).
I heated my previous home exclusively on mixed split hardwoods for the first two years we lived in it. My experience with the typical loading frequency with the blocks (in order to regain a fire without taking extraneous measures) is nearly identical to my experience with split hardwoods.
For what it's worth, mixed, unseasoned, and highly green hardwoods have only about 2,600 BTU's per pound (based upon 60% moisture). Wood at a hypothetical zero percent moisture would have about ~8,400 BTU's per Lb. And also for what its worth, when metering wood by the pound instead of by volume, a pound of soft pine wood at 25% moisture (etc...) and a pound of hickory or oak (etc..., when also at 25 % moisture) both have ~6,400 BTU's.