ABSTRACT
Phase change material (PCM) has been considered for thermal energy storage (TES) in buildings since before 1980. The use of PCM can overcome the lack of coincidence between energy supply and energy demand and can be applied in buildings as passive and active systems. Passive TES systems can enhance effectively the naturally available heat energy sources in order to maintain the comfort conditions in buildings and minimize the use of mechanically assisted heating or cooling systems. There are four primary functions of the containment capsule: to meet the requirements of strength, flexibility, corrosion resistance, and thermal stability; to act as a barrier to protect the PCM from harmful interaction with the environment; to provide a sufficient surface for heat transfer; and to provide structural stability and easy handling. One approach to the use of nanoparticles to decrease PCM leakage in cement-based composites is to increase the capsule strength of microencapsulated PCM.
