Progressive dryers / channel dryers are suitable especially for large sawmill with high throughput (E.g. 120,000 m m³ per anno). This dryer type of interest is also for large pallet producers. The loading and unloading is done through a fully automatic transport system. At regular intervals, completely dried wood packages leave the drying channel and wet wood packages are fed to the drying process. Progressive dryers are available as transverse or longitudinal vented dryers. In recent years the cross ventilated system (counter flow principle) has gained more and more importance because it best suits the natural drying of wood, and is also more energy efficient. The installation of additional IRI reduces energy consumption to a minimum.