Heating values of various woods

Note that actual heat obtained from wood will depend greatly on moisture content of the wood, efficiency of the furnace, stove, or fireplace, etc.

Wood type MMBtu per cord
Apple 29
Aspen 17
Cottonwood 16
Elm 20
Fir, Douglas 26
Hickory 28
Maple 22
Oak 26
Pine, Lodgepole 17
Pine, Pinon 31
Pine, Ponderosa 19
Pine, White 15
Spruce, Englem 16