Abstract: A wood drying kiln and airflow controlling process is described in which the kiln includes an structure with a charge receiving chamber, and a door accessible opening to allow passage of a charge of lumber for drying. Circulating fans in the structure produce airflow that is directed by baffles in a prescribed path through the charge. At least one row of elongated resilient brush bristles within the structure are positioned therein to yieldably engage the charge of lumber placed within the charge receiving chamber. The brush bristles are provided with sufficient density to limit passage of air laterally through the row.