This bachelor's thesis deals with the issue of pre-drying of lumber and pre-drying energy wood chips. In the introduction, the work generally characterizes the drying process. Subsequently, characterizes natural drying, artificial pre-drying and energy chips. It deals with the analysis pre-drying wood and its comparison to natural drying of wood. It deals with equipments for artificial pre-drying of lumber and for pre-drying of energy chips. In the final chapters it deals of the intensity pre-drying using drying gradients. Compares and assess different times of pre-drying and natural drying