Optimum Thermal Insulation Thickness for Building in Different Climatic Regions in Sudan

Abstract

The optimum thermal insulation thickness for buildings under Sudan climate regions was studied. Energy consumption especially of the building sector, are an important part of the total energy consumption in Sudan. The building sector was the large consumer of energy more than 50% of the consumed total energy in the building has been consumed to heating and cooling this due to the hot climate in Sudan and the majority of buildings in Sudan do not have insulation. The residential sector consumes 56.7% from the total electrical energy consumption in Sudan. The insulation performance of the external walls of a building is a critical factor for energy consumption of air conditioning system. It is very important to properly select the type of insulator, applying insulation at optimum thickness considering investment and operating costs. Heating/Cooling degree days method (HDD/CDD method) analysis with the life cycle cost analysis LCCA and approach for optimization of insulation materials thickness, energy saving, and payback period , and MATLAB software is the methods used in this study to calculate heating and cooling load which is the one of an input parameter used in the calculation of optimum insulation thickness, the present research employed the CDD technique to determine the optimum insulation thickness, energy saving, and payback period after the insulation materials had been applied to the exterior walls of buildings for four selected cities in Sudan namely Khartoum, Dongola, Port Sudan, and Nyala each city have different climatic conditions. The optimum insulation thickness calculated for external wall with three different insulation materials Extruded polystyrene (XPS), Expanded polystyrene (EPS), and Glass wool (GW), applied for three different wall types fired clay bricks, perforated red brick, and cement hollow block. The results show that the optimum insulation thicknesses vary between 6 and 41 mm depending on the city. Optimum insulation thickness for the external wall in Khartoum, Dongola, Port Sudan,and Nyala were 15, 14, 14 and 6 mm respectively for the extruded polystyrene(XPS) material used perforated red brick, and 19,18, 17 and 8 mm respectively for the expanded polystyrene (EPS) material used perforated red brick, and 28, 27, 26, and 15 mm respectively for the glass wool (GW) material used perforated red brick. The energy cost savings and payback periods due to optimum insulation thickness was determined for each selected cities for various insulation materials. It is seen that the energy cost savings vary between 0.4 and 13.1 $/m2 depending on the insulation material. The highest optimum insulation thicknesses and energy cost savings is reached by using glass wool (GW) as the insulating material in Khatoum, while the lowest value is reached by using Extruded polystyrene (XPS) as an the insulating material in Nyala. Energy cost savings are 48.3% in Khartoum, 47 % in Dongola, 46.2% in Port Sudan, and 35.1in Nyala for the extruded polystyrene materials. Also 55.3% in Khartoum, 54.1 % in Dongola, 53.3% in Port Sudan, and 43.2% in Nyala for the glass wool materials.