Кey Words: Latent heat; fluids; crystallization; melting; vaporization; liquefaction; free water; bound water.
Abstract. Some basic characteristics and terms of the latent heat of solidification, fusion, vaporization, and liquefaction of the substances are being considered in this work. The processes of crystallization and vaporization of the substances have been described and analyzed. Theoretical foundations of the solidification and vaporization processes of the substances are in short given. Using data from the specialized literature, approaches for the calculation of the specific latent heat of fusion and vaporization of both the free and the bound water in capillary porous materials has been presented. The information about the specific latent heat of the water in mentioned materials is needed for scientifically based computing the non-stationary temperature distribution and energy consumption during their freezing, defrosting, drying, and model based control.