The bachelor thesis is focused on observing and scoring of regulation of speed and streaming during drying of lumber. The object of observation is spruce and beech lumber. Expert articles from respected authors and one master thesis were used as sources of this thesis. Furthermore, the content of the thesis is observing of energy consumption and influence of various stream speeds on the effectiveness of drying, overall quality of lumber and quality of lumber surface. The results and observations are presented both by words and graphically.