ENVIRONMENTAL AND ECONOMIC IMPACT OF USING RECYCLED MATERIALS IN WALL INSULATION : Energy management for sustainable cities, ETC building project.

Abstract: Recycled material has attracted extensive interest due to its positive impact on decarbonization in the building sector. At the same time, utilizing these materials is limited. The main objective of this degree project is to provide a better understanding of recycled materials and their role in environmental and economic aspects. This work investigates three cases regarding the use of recycled materials as external wall insulation in ETC buildings: Case 1 (biochar), Case 2 (plastic waste materials), and Case 3 (straw bales), and the cases will be compared with Case 0 (wood) materials that are used in the building. Thermal insulation properties such as thermal conductivity and density are the most important factors influencing this material's ability to insulate. These properties are used as variables in simulation; each variable is linked to the type of material used. Models were created for each material in the building performance simulation tool IDA ICE. In each model, the insulation of the external walls will be changed, but the rest of the construction specifications will stay unchanged. The results showed that all the materials selected in the evaluation have a low environmental impact (thermo-environmental assessment), low energy demand, and low carbon emissions. In the case of comparing the three cases 1, 2, and 3 of recycled materials, the results indicated that Case 1 (biochar) has the same environmental impact as Case 0 (wood), but the energy used was more than Case 0 by 6%, and the economic impact (thermoeconomic assessment)regarding energy costs has the same value. There is no information regarding the material’s price. The results showed that Case 3 (straw bales) has a lower environmental and economic impact than wood. The results illustrated that adding Case2 (EPS) with a thickness of 200 to the wooden building reduced demand by 3% for heating and cooling, and the energy used was less than 2%. Therefore, Case0 (wood) support with this layer is considered an appropriate solution to reduce energy demand. On the other hand, recycled materials have challenges in terms of insufficient research on the extent of their use, as in the case of biochar in Sweden. As well as challenges related to the development of strawbales, which have many problems related to rotting and moisture absorption