الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Exterior building envelopes are exposed to many forms of thermal loads and are also the essential thermal element for heat transfer in buildings. Which leads to temperature increased, and consequent energy consumption increased in buildings. Accordingly, efficiency and energy system improvement in buildings and energy improvement techniques for buildings are the main important modern studies that concentrate on new techniques and methods of saving energy consumption and improving the thermal performance in buildings. Thus, the walls and ceilings and cement mortar (i.e., mortar plaster) of buildings are the primary thermal mass elements of heat transfer to interior void in buildings. Therefore, thermal energy storage (TES) using new techniques and methods, such as the utilization of Phase Change Materials (PCMs), is a new development strategy for buildings projects with high energy performance. The concept of incorporating TES technologies in buildings is gaining prominence as TES technology bridges the gap between energy supply and request and provides energy security. PCMs are among the environment-friendly, economic energy storage technologies that have gained significant research interest over the past decade. PCMs can absorb and storing energy and then releasing high amounts of energy through the phase change stage. The main objective of this study is to save the energy of buildings by using PCMs new techniques in walls, ceiling, and cement mortar. For achieve the research objectives of this study where the experimental program was designed. The program consists of two parts, part one is to study walls and ceiling with PCMs (i.e., paraffin wax), and part two is to prepare and produce micro-PCMs by using local materials and studied the effects of micro-PCM addition in cement mortars on the thermal performance improvement. Part One, the objective of this part is to save the energy of buildings by using paraffin wax as phase change materials (PCMs) and pumice fine aggregates (PUs) with concrete hollow blocks (CHBs) by using the cement mortars into the walls and ceilings (CILs). The effects investigated on temperature reduction and their role is improving thermal performance, thermal comfort, and electrical consumption energy savings of buildings. Eight concrete hollow blocks CHBs specimens were prepared using the cement mortars. The first group consists of four specimens included CHBs (Standard; without mortar) and the other three mixtures with different percentages of PCMs (0%, 50%, and Abstract vi Phase Change Materials 75%) by volume of sand. The second group was prepared using PUs aggregate that consists of three CHBs specimens with different percentages of PCMs (0%, 50%, and 75%) by volume of PUs, that prepared to investigate the effects of PUs aggregate and PCMs replacement on the thermal properties. The eighth CHBs specimen was filled with pure PCMs. The thermal properties of the prepared specimens were performed by Differential Scanning Calorimetry (DSC), thermal Conductivity (K- Value), and heat transfer evolution (HTE) analysis technique. Four rooms were built with a 6 cm ceiling thickness and CHBs walls, to study the effect of PCMs and PUs on the thermal properties. The temperature evolution in the rooms and the offset peak hours, cooling load, and energy cost savings were investigated. Part Two, because the cement mortar is a primary element for heat-transfer the envelope of buildings. This part aims to prepare microencapsulated-PCMs (micro-PCMs) by using local materials and studied the influence of adding micro-PCMs to cement mortars on thermal performance improvement and maintaining their physico-mechanical properties. The micro-PCMs of paraffin wax was prepared as the core PCMs materials while the melamine-formaldehyde polymer was the shell, for PCMs leakage problems improvement. The micro-PCMs were characterized through scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectrometry, Fourier-transform infrared spectroscopy, and differential scanning calorimetry. Moreover, cement mortar with micro-PCMs was investigated. Microstructure analysis (i.e., SEM-EDX) was performed to study the thermal and physical-mechanical properties of the mortar with micro-PCMs. Results of part one indicates improving the thermal properties of the tested specimens. The room results show a decrease in the indoor temperature of the room with 5.75 °C. The cooling load reduction was 26%, corresponding to an electricity consumption savings of approximately 25%. Based on all results, thermal performance tests showed that the modal room with the PCMs + PUs can be improved thermal comfort keeping the indoor temperature at the comfortable range for a large time and reduced the electrical consumption energy of buildings. Analysis results of part two showed the prepared micro-PCMs present a regular spherical shape and confirm that the formation composite of the shell effectively encapsulated the cores. Furthermore, the absence of chemical interaction between the micro-PCMs and the cementitious components. The mechanical tests indicate that a Abstract vii Phase Change Materials reduction with increasing of micro-PCMs in cement mortar. However, mechanical properties satisfied the requirements of the minimum specification of the cement mortar. Finally, the obtained results indicate that the PCMs with PUs into CHBs, PCMs with ceiling and micro-PCMs in cement mortar can successfully be used due to having potential for architectural applications in the building-envelope to store thermal energy, provide indoor-temperature at the comfortable range, and reduce the consumption energy in buildings with maintaining their physico-mechanical properties of elements.