Energy, environmental, and economic analysis of different buildings envelope integrated with phase change materials in different climates

Several technologies were been developed to store the solar energy for different applications especially in the construction sector. Integrating phase change materials (PCM) into building is one of the effective solutions for energy efficiency. This paper aims to evaluate the optimal envelope type and climatic zone able to improve the performance of buildings using PCM. A numerical simulation was conducted using the difference finite method by Energy plus, in three climates of North Africa; Mediterranean, arid and sub-arid climate, concerning four different building envelopes (brick, concrete block, reinforced concrete and earth) to analyze the energy, economic and environmental impact. The maximum values of energy saving rate is found in the arid and sub-arid climate, with the highest value of 10.5 % for earth envelope, and the lowest value of 2.57 % for concrete block envelope in Mediterranean climate. The use of PCM is more efficient for cooling in arid climate for the different considered envelopes with a maximum of cooling energy reduction of 7.3%, and its use in the sub-arid climate and the Mediterranean one is more efficient for heating with a maximum value of 10.7% in the earth envelope. The environmental and economic analysis shows that the use of PCM in optimal conditions can reduce 10 % of energy cost and 707 kg/year of CO2 emissions. Furthermore the payback period obtained varied between 7 and 43 years with an average of 23 years. Conclusively, the use of PCM for thermal energy storage in buildings still a good solution for energy performance.