We’re going to make this simple for you. Pound for pound, all woods create the same amount of BTUs. Does this mean that a cord of seasoned pine puts out the same amount of heat as a cord of seasoned hickory? No! The hickory will produce twice the amount of BTU’s (British thermal unit) of the pine because it weights roughly twice as much as the pine.
So if one threw three 18 inch long, 4 inch round, seasoned hickory logs into their wood-burning smoker, they would create about twice the heat of three pine logs the same size, for the hickory is much denser and heavier. But, if one was to put 20 pounds of pine, or 20 pounds of hickory into the firebox, the overall heat would be the same. Now understand the pine would burn much faster, and give off a lot of heat quickly, then die down, whereas the hickory would burn much more slowly, and give off its heat at a slower rate. By the way, pound for pound, green wood gives off much less BTUs than seasoned wood, for it takes a lot of the heat energy to evaporate the moisture out of the green wood (i.e. turn it to steam). Do not ever use pine for barbecuing–We’re only using it here to show the differences in wood density.
- A cord of hardwood is about 12,500,000 BTUs of heat.
- A hundred gallons of heating oil is 13,600,000 BTUs of heat.
- Natural gas has a 1000 to 1100 BTUs per cubic foot.
- Propane has 2519 BTUs per cubic foot or 21,670 BTUs per pound or 92,600 BTUs per gallon.
- Note that the hardwood is an estimate that will vary depending on how tightly it is stacked, the mix of wood, and the seasoning of the wood.
- As long as I’m tossing numbers, a ton of coal is 25,000,000 BTUs and a pound of Styrofoam is 18,400 BTUs.
So, to answer the original question, the harder the wood the more power is packed into the same volume. Wood density can vary considerably in the same tree so you will find little specific information about the heat content of a species.