KSU shows sugar maple and red oak at the same 24 million BTU's per green cord. Silver maple is most plentiful in our area and it's only 18.9 M BTU.
Those BTU charts are nice for making comparisons but I wouldn’t live and die by them. The thing is they can’t tell the whole story. Most are based only on weight at 20% moisture content… a mathematically derived number. Those BTU numbers are “potential” only… usually not anywhere near what you’ll actually get as output into the living space around the stove. And different wood burning appliances will “extract" more or less heat depending… For example a lot of OWB guys burn Cottonwood without complaint.
The burning characteristic of individual species has a lot to do with how many of those BTU’s you can realize as heat value. For example, if you have two different kinds of wood rated at identical BTU’s (weight) and one burns fast with very little coaling while the other burns slower and coals-up… well, the faster burn will send more heat out the flue. Take, as another example, Douglas Fir and Box Elder which are usually rated as containing the same “potential” BTU’s (18 million). A couple years back I burned some Douglas Fir in my old furnace and I can testify that it’s at least 3 times the firewood Box Elder is. Fact is, most of the pines listed as containing fewer BTU’s make far superior heating firewood than Box Elder.
I think this is where elm gets short-changed, because its placement on the BTU chart doesn’t do it justice. American Elm is far better firewood than many of the other species it’s normally listed close to, such as the soft maples, cherry and walnut. And Red Elm really gets slammed; I’d put Red Elm every bit as good as any of the red oaks… maybe even better than some.
Anyway, just some ramblings not really on topic (but it is my thread :msp_tongue… take it for-what-it’s-worth.
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