Writes for building services designers, to provide them with independent information concerning the practical application and operating issues for thermal storage systems and to assist them to achieve optimum performance of thermal storage systems. Also addresses system operators, by highlighting the principal problems encountered as part of the project in using thermal storage, and recommending solutions to these problems. Describes the practical applications and performance of the most common thermal storage systems in use. Also provides system case studies, together with feedback of the lessons learnt during the course of monitoring these systems.