The BTUs that a cord of wood produces varies between types of wood. A cord of white oak produces 29.1 million BTUs, while a cord of white pine produces 15.9 million BTUs.
When burning wood as a heat source, dry wood is preferable over green wood. Green wood contains more water and produces less heat and more smoke and creosote than dry wood.
The best wood to use in fireplaces is wood that is dense or heavy, like cedar and oak, which produces little smoke and does not pop or spark. Conifers, such as spruce and pine, throw out many sparks, which could cause a fire in the home.