Wood Drying kilns are used at saw mills and treatment plants to lower the moisture content of lumber to a selected desired level
. The lumber fed into drying kilns is typically "green" lumber, cut from previously living trees and that typically has high moisture content. The lumber is dried usually by application of heat and airflow directed through and around layers of lumber arranged in stacks forming a charge within the kiln chamber.
Wood Drying kilns are a faster alternative and more consistently controllable than air drying. Stacks of lumber may be effectively dried in just over two days, depending of course on the species of wood, initial moisture content, and other considerations that can affect drying time. On the other hand, air drying of the same material may take several months or more. Expediency is clearly an advantage in kiln drying over air drying, but need remains for efficient kiln systems that will provide for expeditious drying at low cost.