Abstract: A single-pass lumber kiln includes a main drying chamber, a heat source to provide heat to the main drying chamber, a pre-heating chamber connected to a receiving side of the main drying chamber, the pre-heating chamber having a moisture collector and a kiln entrance, a supplemental heat source to provide heat to the pre-heating chamber, a conditioning chamber connected to an exit of the main drying chamber, the conditioning chamber having a moisture delivery system and a kiln exit, wherein the pre-heating chamber, the main drying chamber and the conditioning chamber are positioned such that lumber entering the kiln travels in only one direction, partitions between the main drying chamber and the conditioning chamber, and between the main drying chamber and the pre-heating chamber, the partitions having controllable dampers, fans arranged adjacent the pre-heating chamber, the conditioning chamber, and the main drying chamber, wherein some of the fans are arranged between the pre-heating and main drying chambe