Thermal Energy Storage (TES) is the temporary storage of high or low temperature energy for later use. It bridges the time gap between energy requirement and energy use. For HVAC and refrigeration application purposes, water and water ice constitute the principal storage media. Water has the advantage of universal availability and low cost but for sensible energy storage capacity it requires large storage tanks.

Phase Change Materials (PCM) between +4° C (39° F) and +90 C° (242° F) range over comes the water disadvantages by combining the latent and sensible energy storage capacities into a single storage unit and therefore offering designers new horizons and practical applicaiton options. PCM latent heat coold energy stoarage can be provided by utilising conventional water chillers for new and retrofit applications without the need for any modifications as well as having the possibility of free cooling.

By storing day-time warm energy for evening periods and over-night cool energy for day-time cooling requirements, a PCM system can simply bridge the gap between energy availability and energy use and therfore has the potential to achieve considerable environmental as well as economical benefits for many heating and cooling applications.

The aim of this paper is to raise awareness of commercially available PCM solutions and products together with their practical worldwide applications. Typical installation examples around the world will be presented in a format that will aid practising engineers and consultants to develop an effective and low energy based design on PCM based TES cooling / heating and heat recovery systems.