Energy Savings and Optimum Insulation Thickness in External Walls in Palestinian Buildings

The determination of the optimum wall insulation thickness (OWIT) of the building’s external wall has major drawbacks on building wall thickness, insulation material type, insulation cost, and energy consumption by air conditioning system. Therefore, this study focused on a systematic approach for optimization of insulation thickness for building’s external wall in Palestine. Hence, the environmental conditions such as temperature and solar radiation fluctuations were collected for the cities covered in this study over one year while preparing this study. The Palestinian energy-efficient building code divided Palestine into seven climate zones. These zones are studied and investigated in this study. The OWIT in these zones has been calculated and compared based on the life cycle cost analysis and for two different types of insulation which are Expanded Polystyrene (EPS) and Polyurethane (PUR). Consequently, life cycle savings of the insulated buildings, simple payback periods, and optimum insulation thickness as a function of degree days and wall thermal resistance have been addressed. These types of comparisons and findings could promote the futuristic use of optimum insulation thickness in Palestinian buildings towards establishing a Palestinian standard code.