Wood burning gas fireplaces can use different types of woods like soft wood or hard wood. Both provide have same energy and provide more or less same warmth. The only difference is the duration up to which each lasts. Softwoods are obtained from evergreen trees and burn at faster rate while hardwood is obtained from slow growing broadleaf trees which burn at slower rate. Before using wood in the Wood burning gas fireplaces, the moisture content of the wood must be checked. Freshly cut woods have higher moisture content and thus should not be used in a fireplace. For best results, wood used in a fireplace should not have a moisture content of more than 20%. For removing the moisture in the wood, kilns are used. They dry out the wood so that it can be easily used in a fireplace.