A comprehensive state-of-the-art review of sustainable thermal insulation system used in external walls for reduction in energy consumption in buildings

In general, to regulate the indoor room temperature, the heating and cooling of a building require more energy for active heating and cooling devices other than the energy consumption of other electrical, electronic household devices. The external wall in a building plays a vital role in determining the resistivity against the heat loss or gain. Previous studies reputed that the temperature inside the building was regulated using high thermal mass. But, now with the advances in construction practices, thermal insulation is one of the efficient technologies used for providing indoor comfort with its properties. Insulation for heat is to provide a layer of insulation materials which would curtail the heat gain or loss, which minimizes the power consumption of heating or cooling devices. Commercially a lot of insulation materials are used with high performance in thermal resistance. There is more scope to develop a cost-effective thermal insulating material that possesses excellent performance with less environmental impact. In this review paper, the performance of the different thermal insulation composites used for thermal insulation of exterior walls of a building is presented. The influence of the optimum thickness of the material in saving energy is another vital element to be discussed for the insulation composites. The economic and environmental impact of the insulation composites are elaborated with performance parameters and material properties.