The project objectives are to develop and accurately characterise the thermo-fluid properties of fluid dispersed microencapsulated phase change materials with phase transition temperatures suitable for a range of built environment based heating and cooling and solar thermal applications. An extensive series of experiments and detailed simulations will be used to develop appropriate systems with improved energy efficiency and performance compared to those currently available and adopted by best practise. A financial and environmental impact analysis to determine the resulting benefits from estimated levels of market penetration for the developed technology will be undertaken. The problems to be solved include the development of suitable phase change material slurries and specification of equipment in view of improved material characteristics.