This dataset corresponds to a study aimed at evaluating the hygroscopic behaviour and corrosion effect of inorganic compounds to be applied as phase change material (PCM) in a laten heat thermal energy storage (TES) system. The hygroscopy test consisted of analysing the rate at which inorganic compounds can absorb water during 8 hours of exposure to the environment and the amount of water removed in 12 hours of subsequent drying. The corrosion tests consisted of analysing the changes produced by static orrosion in stainless steel fibres when they are immersed one week in different liquid inorganic PCMs as first tests for PCM selection.