ABSTRACT
Hardwoods such as American (Yellow, Gray, Black) and European (Silver, Downy) Birches, Aspen, Elm, Eucalyptus, Maple, Oak (Red, White), Poplar, and Walnut are usually dried in convective-type kilns at low temperatures by using energy sources as fossil fuels or biomass. Electrically driven, low-temperature mechanical vapor compression air-to-air heat pumps are also used in combination with fossil fuels as supplementary and backup energy sources. This chapter discusses experimental site, typical drying schedule, experimental results, operating parameters, drying performances, energy consumption, and energy costs of the case studies such as low-temperature heat pump-assisted hardwood drying, high-temperature softwood drying—Laboratory Scale, and high-temperature softwood drying—industrial scale. The basis for determining the softwood kiln drying seasoning strategies depends on how moisture moves through softwood boards.
