Moisture can form on material surfaces. This moisture may be in the form of free water or adsorbed water. Removal of free water is relatively easy, while removal of adsorbed water is not quite so easy. There is no doubt that moisture on the surface can be removed by the application of heat. The result is moisture movement into the material. Drying, on the other hand, may cause moisture to move out of the material to the surface. This can be achieved by drying which combines large volume rates of flow of drying air with moderate heating (the HYAB method). This drying method is competitive not only from the technical but also from the economic point of view. The method can be used not only to dry porous materials, which is a criterion for many surface treatment and impregnation methods, but also to remove films of moisture from metals and to thaw out materials. -- AATA