When solar radiation reaches its peak or when the temperature drops to its lowest point during the day, the roofs and walls of buildings absorb or release the maximum amount of energy, leading to a significant increase in cooling or heating load and consequently higher energy consumption. The knowledge of Thermal Energy Storage (TES) and the use of innovative materials and systems in the construction industry contribute to the energy efficiency of buildings. One of the newest methods is the use of Phase Change Materials (PCM) in the construction of materials and building components. To reduce energy consumption, enhance energy efficiency, and improve and maintain thermal comfort in buildings, this study produced a new type of thermal insulation panel made of foamed concrete containing PCM with the capacity to store and release thermal energy. The produced foamed concrete panels, with thicknesses of 7 and 15 cm, contained 10% and 20% by weight of polyethylene glycol 600, shape-stabilized by microsilica and rice husk ash, with a phase change temperature of 18.6 °C. The panels were tested under the temperature profile of a summer day in the cities of Isfahan, Mashhad, and Urmia. To eva‎luate the thermal performance of the panels, a "Daily Temperature Simulator" device was used. The maximum temperature reduction of the internal space of the specimens, the final maximum temperature, and the standard deviation of the daily temperature were examined as criteria to assess the thermal performance of the specimens. The results show that specimens with a thickness of 15 cm exhibited better thermal performance compared to the 7 cm specimens, and increasing the percentage of PCM resulted in reduced temperature fluctuations and the highest amount of temperature reduction. Additionally, in this study, compressive strength, tensile strength, water absorption, and durability tests against 100 and 150 freeze-thaw cycles were conducted. The results indicate that increasing the amount of PCM reduced water absorption and the compressive strength of the specimens at early ages, which was fully compensated at later ages due to the presence of microsilica and rice husk ash.

مرتضي مدح خوان

كياچهر بهفرنيا , مريم داعي