الفهرس 
Chapter (1) Scope and Aim of StudyOnly 14 pages are availabe for public view
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Abstract
Achieving the concept of energy-efficient building (EEB) is a promising direction for global energy saving. The incorporation of phase change materials (PCM) in the building structure is one of the new techniques recently applied in EEB. Therefore, the main goal of the present study was to investigate the thermal performance of a building roof integrated with a phase change material (PCM).An experimental test Rig was designed and constructed to obtain experimental data for the behavior of melting and solidification of PCM inserted into roof structure. Also, two computational models were developed to predict the thermal performance of the building roof integrated with PCM. The first model is precise, called melting and solidification model (M/S model); requires long computational time, and the second is simplified model (SD model); requires less computational time. The two models are simulated using ANSYS-Fluent. The two models are compared and validated with the experiments conducted in this study and with data in the literature. The (M/S model) is essential to capture the melting behavior inside the PCM layer, while the SD model is the appropriate model for long-term simulation. The M/S model was used to predict the thermal performance of a real building roof exposed to a real weather condition in Egypt, and integrated with various types of PCM (RT27, RT31, and RT35HC) with different thicknesses (20 mm, 40 mm, and 60 mm). The SD model was used to predict the thermal performance of both roof with and without PCM in hot summer season of Aswan, Egypt. The numerical simulation was performed for two short periods of time (one-day simulation) and (one-week simulation) as well as for long period of time (four-month simulation).The results showed that, using PCM in the roof structure decreases the indoor heat flux and attains an indoor wall temperature closer to the indoor air temperature requirements. Further, the larger thickness of the PCM, the better performance. The long-term simulation (four-months in summer season of Aswan city, Egypt) show that the use of PCM of RT31 and RT35HC with thickness of 40 mm, has reduced the average indoor wall temperature by about 3oC, and the total energy transfer by about 40%.