Latent heat storage material formulations

Latent heat storage material formulations formed from a mixture comprising a binder, a phase change material and water wherein the weight ratio of the binder to water used in the preparation of the latent heat storage material is in the range 3:1 to 1:5, and preferably 1:1 to 1:5 and processes for their preparation. It also includes composite panel assemblies or encasements including those latent heat storage materials and processes for their manufacture. The binder may be a cement, an Ordinary Portland cement, a magnesia cement, a pozzolan cement or a magnesium chloride solution.