Optimum Insulation Thickness and Environmental Impact Mitigation of Residential Buildings Wall

The optimum insulation thickness of residential building walls is determined according to the energy sources available in local market, in order to reduce CO2 emissions and thus mitigate the environmental impact related to the energy consumption. The building sector is very energy intensive, which affects the environment and therefore contributes to global warming. Introducing a layer of insulation in the exterior walls can reduce energy consumption and consequently has more ecological and sustainable buildings. The optimization procedure includes the estimation of the heating and cooling loads with the degree-day method, the determination of the optimal insulation thickness with the improved life cycle cost analysis model and the assessment of the environmental impact. The window size is considered in the optimization procedure as new variable and varies between 0 and 50% of the total wall area. As a result, the optimal thickness varies between 1.9 and 10.2 cm for the city of Algiers and between 0.8 and 10 cm for Tamanrasset according to the type of fuel and the size of the window. The emissions resulting from the use of natural gas are close to those resulting by the use of electricity and this is due to the efficiency of the heating and cooling system. The use of electricity associated with the optimal insulation thickness offers the best reduction of costs and the reduction in the environmental impact can reach 86.35%.