Dry wood means an efficient burn The drier the wood the more seasoned it is, and the more efficient the burn is; the wood produces more useful heat. Burning wet wood produces moisture, which creates creosote buildup and promptes rusting of the firebox. But to select, split and season quality wood that will give you optimum burning efficiency takes time and money. A forced air draft furnace will burn almost any quality of wood, wet, green or dry. The amount of useful heat will vary with wood quality, but it will burn. A short chimney with the forced air draft will reduce the possibility of creosote.