Nowadays the environmental sustainability and the limitation of the energy consumption of buildings is of substantial importance in order to reduce greenhouse gases emissions and mitigate the consequences of climate change. Thermal energy storage (TES) allows to store thermal energy when available in order to use it when and where necessary. The use of insulating materials with TES capability may results in the compensation of energy absorption peaks caused by air conditioning or by space heating with a consequent reduction of energy consumption and related CO2 emissions. This work aims at the development and characterization of composite materials based on polymeric foams and containing a phase change material providing the TES capability. The production procedures were optimized in order to maximize the quality of the samples and the main properties of the resulting materials were then investigated. Different matrices were considered in this work: thermosetting, thermoplastic and elastomeric ones. As thermosetting matrix, a polyurethane foam was considered: this foam was filled, during the production process, with increasing amounts (from 10 to 40 wt%) of a microencapsulated PCM with a melting point of 24 °C. The addition of the PCM caused the disruption of the regular close cell morphology of the foams with a consequent increase of the thermal conductivity and a reduction of the mechanical properties. On the other hand, the addition of the PCM led to interesting TES properties, measured both through differential scanning calorimetry and infrared thermography (up to 54 J/g). Polyethylene was chosen as thermoplastic matrix and the technology of salt leaching was used to obtain foams without the use of chemical foaming agents. Foams containing different amounts (up to 56 wt%) of a microencapsulated PCM with a melting point of 24 °C were prepared. The addition of the PCM led to a decrease of the connectivity and porosity values of the prepared foams with a consequent decrease of the mechanical properties and increase of the thermal conductivity. Despite the rupture of a certain part of the PCM capsules due to the production process, good TES properties (up to 50 J/g) were measured. Elastomeric foams were prepared using an EPDM rubber as matrix and different foaming agents for the expansion process: foams obtained using two different commercial foaming agents were compared with foams obtained using the salt leaching technique. In the first case, a shape-stabilized PCM was added during the production process, while in the second one the foams were impregnated with a liquid PCM without the necessity of a shape stabilization. Salt leaching foams were able to retain higher PCM loads with respect to foams produced using commercial foaming agents and were therefore characterized by higher TES capability (up to 129 J/g). Infrared thermography tests highlighted that the time required to reach a reference temperature during heating/cooling cycles was three times longer for samples with a PCM amount of about 55 wt%. These foams evidenced a general decrease of the mechanical properties upon PCM addition. Moreover, a strong influence of the temperature on the mechanical behaviour of these foams was highlighted, with the PCM acting as softener above its melting point and as hardener below. In order to consider practical applications, elastomeric panels made of an ethylene propylene diene monomer (EPDM) rubber filled with a shape stabilized PCM and covered with a nitrile-butadiene rubber (NBR) envelope were prepared. It was possible to verify the absence of leakage, the uniform distribution of the PCM and the influence of temperature on the mechanical properties of the samples. From rheological tests it was also possible to observe the plasticizing effect of the PCM that hindered the vulcanization process of the EPDM/PCM compound. In the second part of this work larger samples were prepared and used for the internal insulation of wood boxes that were subjected to heating/cooling cycles, simulating thus real summer conditions in north Italy. The beneficial effect of the PCM resulted in a consistent reduction of the temperature peak with respect to a reference box insulated with elastomeric panels without PCM. Moreover, the fire behaviour of the produced samples was studied and the effect of the addition of different flame retardants was deeply investigated. The addition of a flame retardant based on ammonium polyphosphate and aluminium diethyl phosphinate as synergistic agents allowed a strong reduction of the peak of heat release rate measured through cone calorimeter tests, with a significant improvement of the fire behaviour. Fire tests allowed also to point out the significant role, in improving the fire performances of the samples, of the interactions between ammonium polyphosphate and the mineral fillers present in the EPDM/PCM compound (clay) and in the envelope (talc, kaolin and silica). A better comprehension of the combustion mechanisms and of the flame retardant efficacy was achieved through the analysis of the combustion residues. Finally, the specific enthalpy of the different systems was evaluated with respect to the cost of the raw materials used in the production stages in order to classify them on the basis of their melting enthalpy and on the economical aspects.

Energy has always been the dominant driving force for the socio-economic development of mankind. Nowadays, the global energy system is highly depended on fossil fuels. A great share of the final energy consumption, over 40%, in the EU-27 is consumed by the existing building stock whereas dwellings account for 66.62% of this. Thus, the need to increase the energy performance of dwellings is an important instrument in the efforts to lessen Europe’s energy dependency. In order to define measures to increase the energy performance of dwellings a deeper understanding of their characteristics should be gained. Unfortunately, in Cyprus there is a gap in knowledge on this aspect. In this thesis the characteristics of the dwellings in Cyprus are defined through a sample of 500 dwellings. The results revealed that more than 80% of dwellings in Cyprus do not have thermal insulation installed on their envelope. From this it is clear that the definition of the optimum thermal insulation material to be applied in dwellings is very important. Thus, the commercially available thermal insulation materials and topologies used in Cyprus were reviewed and defined through a market survey and the typical dwelling was modelled. The effect of the application of thermal insulation to its energy behaviour was simulated using TRNSYS. This resulted in the definition of the optimum thermal insulation materials and topologies to be applied in both new and existing dwellings. Accordingly, the application of advanced commercially available materials such as Phase Change Materials (PCM) to the envelope of the typical dwelling was investigated. The energy savings achieved by the addition of a PCM layer on the envelope of the typical dwelling was found to be 28.6%. The optimum PCM case was also combined with the optimum thermal insulation combination and an energy saving of 68% was predicted. The incorporation of Renewable Energy Sources (RES) to the typical dwelling was also simulated and studied. Specifically, two types of standalone RES systems were initially evaluated; a solely photovoltaic (PV) system and a hybrid PV-Wind system. The results showed that the solely PV system is a much better option due to the very high solar potential of Cyprus in comparison to the poor wind profile of the island. Subsequently, a grid-connected PV system was also evaluated and the results showed that when a RES system is grid-connected the cost of the system is reduced to half of that of the standalone cases. This research has revealed that the optimum topology combinations to be applied in both new and existing dwellings in Cyprus is thermal insulation plaster or thermal insulation bricks (only for new dwellings) on the external walls combined with expanded polystyrene on the roof. These results will provide valuable information that will assist both engineers and architects in the efficient design of dwellings in Cyprus. The investigation of the application of macroencapsulated PCM showed that these materials are not yet an economically viable solution for application in Cyprus The findings also show that a solely PV system is the optimum RES system to be applied in Cyprus especially when it is grid-connected. The findings of this project are useful for individuals, house builders and designers as well as policy makers for the design of energy saving subsidy schemes.

This study describes a simulation-based approach for informing the incorporation of Phase Change Materials (PCMs) in buildings designed to the "Passive House" standard. PCMs provide a minimally invasive method of adding thermal mass to a building, thus mitigating overheating events. Phase change transition temperature, quantity, and location of PCM were all considered while incrementally adding PCM to Passive House simulation models in multiple climate zones across the United States. Whole building energy simulations were performed using EnergyPlus from the US Department of Energy. A prototypical Passive House with a 1500 Watt electric heater and no mechanical cooling was modeled. The effectiveness of the PCM was determined by comparing the zone-hours and zone-degree-hours outside the ASHRAE defined comfort zone for all PCM cases against a control simulation without PCM. Results show that adding PCM to Passive Houses can significantly increase thermal comfort so long as the house is in a dry or marine climate. The addition of PCM in moist climates will not significantly increase occupant comfort because the majority of discomfort in these climates arises due to latent load. For dry or marine climates, PCM has the most significant impact in climates with lower cooling degree-days, reducing by 93% the number of zone-hours outside of thermal comfort and by 98% the number of zone-degree-hours uncomfortable in Portland, Oregon. However, the application of PCM is not as well suited for very hot climates because the PCM becomes overcharged. Only single digit reductions in discomfort were realized when modeling PCM in a Passive House in Phoenix, Arizona. It was found that regardless of the climate PCM should be placed in the top floor, focusing on zones with large southern glazing areas. Also, selecting PCM with a melt temperature of 25°C resulted in the most significant increases in thermal comfort for the majority of climates studied.

The thesis deals with the preparation, characterization and, in particular, with the switching properties of phase-change material (PCM) thin films. The films were deposited using the Pulsed Laser Deposition (PLD) technique. Phase transformations in these films were triggered by means of thermal annealing, laser pulses, and electrical pulses. The five major physical aspects structure transformation, crystallization kinetics, topography, optical properties, and electrical properties have been investigated using XRD, TEM, SEM, AFM, DSC, UV-Vis spectroscopy, a custom-made nanosecond UV laser pump-probe system, in situ resistance measurements, and conductive-AFM. The systematic investigation of the ex situ thermally induced crystallization process of pure stoichiometric GeTe films and O-incorporating GeTe films provides detailed information on structure transformation, topography, crystallization kinetics, optical reflectivity and electrical resistivity. The results reveal a significant improvement of the thermal stability in PCM application for data storage. With the aim of reducing the switching energy consumption and to enhance the optical reflectivity contrast by improving the quality of the produced films, the growth of the GeTe films with simultaneous in situ thermal treatment was investigated with respect to optimizing the film growth conditions, e.g. growth temperature, substrate type. For the investigation of the fast phase transformation process, GeTe films were irradiated by ns UV laser pulses, tailoring various parameters such as pulse number, laser fluence, pulse repetition rate, and film thickness. Additionally, the investigation focused on the comparison of crystallization of GST thin films induced by either nano- or femtosecond single laser pulse irradiation, used to attain a high data transfer rate and to improve the understanding of the mechanisms of fast phase transformation. Non-volatile optical multilevel switching in GeTe phase-change films was identified to be feasible and accurately controllable at a timescale of nanoseconds, which is promising for high speed and high storage density of optical memory devices. Moreover, correlating the dynamics of the optical switching process and the structural information demonstrated not only exactly how fast phase change processes take place, but also, importantly, allowed the determination of the rapid kinetics of phase transformation on the microscopic scale. In the next step, a new general concept for the combination of PCRAM and ReRAM was developed. Bipolar electrical switching of PCM memory cells at the nanoscale can be achieved and improvements of the performance in terms of RESET/SET operation voltage, On/Off resistance ratio and cycling endurance are demonstrated. The original underlying mechanism was verified by the Poole-Frenkel conduction model. The polarity-dependent resistance switching processes can be visualized simultaneously by topography and current images. The local microstructure on the nanoscale of such memory cells and the corresponding local chemical composition were correlated. The gained results contribute to meeting the key challenges of the current understanding and of the development of PCMs for data storage applications, covering thin film preparation, thermal stability, signal-to-noise ratio, switching energy, data transfer rate, storage density, and scalability.

Das Hochtemperaturverhalten beeinflusst viele verschiedene Prozesse von der Materialherstellung bis hin zur technologischen Anwendung. In-situ Transmissionselektronenmikroskopie (TEM) bietet die Möglichkeit, die atomaren Prozesse während struktureller Phasenübergänge direkt und in Realzeit zu beobachten. In dieser Arbeit wurde in-situ TEM angewendet, um die Reversibilität des Schmelz- und Kristallisationsprozesses, sowie das anisotropen Sublimationsverhaltens von Ge-Sb-Te (GST) Dünnschichten zu untersuchen. Die gezielte Probenpräparation für die erfolgreiche Beobachtung der Hochtemperatur-Phasenübergänge wird hervorgehoben. Die notwendige Einkapselung für die Beobachtung der Flüssigphase unter Vakuumbedingungen und die erforderliche sauberer Oberfläche für den Sublimationsprozess werden detailliert beschrieben. Außerdem wird die Elektronenenergieverlustspektroskopie eingesetzt um die lokale chemische Zusammensetzung vor und nach den Übergängen zu bestimmen. Die Untersuchung der Grenzflächenstruktur und Dynamik sowohl beim Phasenübergang fest-flüssig als auch flüssig-fest zeigt Unterschiede zwischen den beiden Vorgängen. Die trigonale Phase von GST weist beim Schmelzen eine teilweise geordnete Übergangszone an der fest-flüssig-Grenzfläche auf, während ein solcher Zwischenzustand bei der Erstarrung nicht entsteht. Außerdem läuft der Schmelzvorgang zeitlich linear ab, während die Kristallisation durch eine Wurzelabhängigkeit von der Zeit mit überlagerter Start-Stopp-Bewegung beschrieben werden kann. Der Einfluss der Substrat-Grenzfläche wird diskutiert und die Oberflächenenergie von GST bestimmt. Die anisotrope Dynamik führt beim Phasenübergang fest-gasförmig der kubischen Phase von GST zur Ausbildung stabiler {111} Facetten. Dies erfolgt über die Bildung von Kinken und Stufen auf stabilen Terrassen. Die Keimbildungsrate und die bevorzugten Keimbildungsorte der Kinken wurden identifiziert und stimmen mit den Voraussagen des Terrassen-Stufen-Kinken Modells überein. / High-temperature behavior influence many different processes ranging from material processing to device applications. In-situ transmission electron microscopy (TEM) provides the means for direct observation of atomic processes during structural phase transitions in real time. In this thesis, in-situ TEM is applied to investigate the reversibility of the melting and solidification processes as well as the anisotropic sublimation behavior of Ge-Sb-Te (GST) thin films. The purposeful sample preparation for the successful observation of the high-temperature phase transitions is emphasized. The required encapsulation for the observation of the liquid phase inside the vacuum conditions and the necessary clean surface for sublimation process are discussed in detail. Additionally electron energy-loss spectroscopy in the TEM is used to determine the local chemical composition before and after the phase transitions. The analysis of the interface structure and dynamic during the solid-to-liquid as well as the liquid-to-solid phase transition shows differences between both processes. The trigonal phase of GST exhibits a partially ordered transition zone at the solid-liquid interface during melting while such an intermediate state does not form during solidification. Additionally the melting process proceeds with linear dependence on time, whereas crystallization can be described as having a square-root time-dependency featuring a superimposed start-stop motion. The influence of the interface is addressed and the surface energies of GST are determined. The anisotropic dynamic of the solid-to-gas phase transition of the cubic GST phase leads to the formation of stable {111} facets. This happens via kink and step nucleation on stable terraces. The nucleation rates and the preferred kink nucleation sites are identified and are in accordance with the predictions of terrace-step-kink model.

Au cours des deux dernières décennies, le contexte économique a changé de manière significative en raison de la hausse des prix de l'énergie. Le bâtiment étant devenu le principal secteur consommateur d'énergie, la réduction de celle-ci est devenue un objectif économique, sociétal et environnemental. Ce sujet mobilise de nombreux travaux de recherche. Les Matériaux à Changement de Phase (MCP) représentent une solution innovante qui pourrait contribuer à améliorer la performance énergétique des bâtiments. Ils sont principalement utilisés pour la régulation de température, et leur forte capacité de stockage est un moyen de réduire la consommation d'énergie. Notre étude vise à caractériser, via une approche expérimentale et numérique, le comportement d'un PCM (l’Octadécane). Pour cela, nous avons développé et mis en œuvre un modèle numérique qui corrobore les résultats expérimentaux, et ainsi améliore la prédiction de la performance du MCP considéré.Dans ce travail, notre principale préoccupation est de mettre en évidence les erreurs ou simplifications présentes dans le modèle numérique traditionnel pouvant entraîner un écart global par rapport au comportement réel du MCP. Ces différences conduisent à une estimation erronée des temps de fusion et de la quantité d'énergie stockée. L'amélioration significative de notre modèle est la prise en compte de la convection naturelle, de la surfusion, et l'utilisation des courbes réelles d'enthalpie du MCP considéré. La relation température-enthalpie réelle tient compte de la présence d'une fraction d'impuretés solubles dans le matériau. L’originalité de ce travail est de traiter ces phénomènes physiques via la méthode de Boltzmann réseau (connue sous l'acronyme LBM) avec des fonctions de distribution doubles couplée à une formulation enthalpique. Une telle approche permet de passer outre la non-linéarité des équations régissant l'écoulement et le transfert de chaleur. Sa simplicité de mise en œuvre et son caractère local permettent d'affiner le modèle. Ainsi, on peut couvrir les problèmes de changement de phase, y compris ceux pouvant avoir lieu dans des matrices poreuses ou fibreuses. Ce dernier point a été couvert dans cette thèse.Enfin, il s'est avéré que l'approche numérique adoptée ici pour traiter les problèmes de changement de phase corrobore à la fois nos résultats expérimentaux et ceux disponibles dans la littérature. / Over the past two decades, the economic context has changed significantly due to the rise in energy prices. The building sector has become the main consumer of energy. Thereby, reducing the latter is now an economic, societal and environmental necessity. Accordingly, this topic mobilizes many researches. Phase Change Materials (PCMs) represent an innovative solution, which could improve buildings' energy performance. They are primarily used for temperature regulation, and their high storage capacity can reduce energy consumption.Our study aims at characterizing, via a complementary approach of experimental and numerical simulation, the behavior of a PCM (n-Octadecane). For this, we have developed and implemented a numerical model that corroborates the experimental results, and hence improves the prediction of the PCM performance.In this work, our main concern is to highlight the common errors or simplifications taken in the traditional numerical model, which can result in an overall discrepancy compared to the actual behavior of PCMs. Those discrepancies lead to wrong estimation of the fusion times and amount of energy stored. The major improvement of our model is the consideration of the natural convection, the supercooling, and the use of real enthalpy curves of the considered PCM. The actual temperature-enthalpy relationship takes into account the presence of a fraction of soluble impurities in the material. The originality of this work is to handle these physical phenomena via a lattice Boltzmann method (known by the acronym LBM), which leans on double distribution functions and coupled with the enthalpy formulation. Such an approach overcomes the non-linearity in the governing equations of fluid flow and heat transfer. Its simplicity and local character allow adding complexity to the model. Thereby, one can cover up the phase change problems, including those, which may occur in heterogeneous matrices. This last point has been also covered in this thesis.Finally, it turned out that the approach implemented here for phase change problems supports both, our experimental results and those available in the literature.

Le stéarate de butyle, un matériau de changement de phase biosourcé (MCP), a été encapsulés dans des matrices polymères (pullulane, lignine, hémicelluloses) par la technique des émulsions concentrées. Les matrices polymères ont été réticulées avec du trimetaphosphate de sodium (STMP) dans des conditions alcalines afin d’obtenir un réseau poreux interconnecté rigide. L’influence du processus de séchage sur les matériaux composites obtenus a été étudiée, indiquant la lyophilisation comme la technique la plus efficace. Des études de calorimétrie à balayage différentiel (DSC) ont permis de déterminer que l’encapsulation de stéarate de butyle dans des matrices polymères ne modifiait pas ses propriétés thermiques de changement de phase. Des essais de compression mécanique et de résistance à la déformation ont permis d'évaluer le potentiel des monolithes en tant que panneaux de stockage de chaleur installés directement dans des bâtiments et des serres.Les produits de réticulation par le STMP ont été identifiés et caractérisés par RMN solide du31P. Il a ainsi été possible de synthétiser des monolithes ayant différents taux de réticulation afin d’optimiser la formulation d'encapsulation de MCP. Les matrices polymères vidée de tous leurs contenus liquides ont été étudiées par microscopie électronique à balayage afin d’étudier leur structure poreuse (distribution de taille des pores). Cette nouvelle approche d’encapsulation en une étape apparaît comme efficace et devrait permettre un développement important des applications énergétiques. / Emulsion-templated polymer based (pullulan, lining and hemicelluloses) monoliths encapsulating butyl stearate as bio-based phase change material (PCM) were synthesized. Polymer-bases were crosslinked with sodium trimetaphosphate (STMP) under alkaline aqueous conditions leading to an interconnected porous network. The influence of the drying process on the obtained composite materials morphology was studied indicating freeze-drying as the most effective technique. Differential Scanning Calorimetry (DSC) studies allow to assess that encapsulation of butyl stearate onto matrices do not alter its phase change thermal properties. Mechanical compression and strain resistance tests allowed to evaluate monoliths potential as heat storage panels installed directly in buildings and greenhouses, STMP crosslinking products were identified by solid-NMR characterization, this allowed to synthetize monoliths at different crosslinking yields to find a formulation that improves PCM encapsulation. Polymer matrices were studied by scanning electron microscopy to identify the pore size distribution obtained in STMP crosslinked materials. This new one-step encapsulating approach appears as efficient and cost-effective and is expected to find a broad development in energy storage applications

abstract: Being a remarkably versatile and inexpensive building material, concrete has found tremendous use in development of modern infrastructure and is the most widely used material in the world. Extensive research in the field of concrete has led to the development of a wide array of concretes with applications ranging from building of skyscrapers to paving of highways. These varied applications require special cementitious composites which can satisfy the demand for enhanced functionalities such as high strength, high durability and improved thermal characteristics among others. The current study focuses on the fundamental understanding of such functional composites, from their microstructural design to macro-scale application. More specifically, this study investigates three different categories of functional cementitious composites. First, it discusses the differences between cementitious systems containing interground and blended limestone with and without alumina. The interground systems are found to outperform the blended systems due to differential grinding of limestone. A novel approach to deduce the particle size distribution of limestone and cement in the interground systems is proposed. Secondly, the study delves into the realm of ultra-high performance concrete, a novel material which possesses extremely high compressive-, tensile- and flexural-strength and service life as compared to regular concrete. The study presents a novel first principles-based paradigm to design economical ultra-high performance concretes using locally available materials. In the final part, the study addresses the thermal benefits of a novel type of concrete containing phase change materials. A software package was designed to perform numerical simulations to analyze temperature profiles and thermal stresses in concrete structures containing PCMs. The design of these materials is accompanied by material characterization of cementitious binders. This has been accomplished using techniques that involve measurement of heat evolution (isothermal calorimetry), determination and quantification of reaction products (thermo-gravimetric analysis, x-ray diffraction, micro-indentation, scanning electron microscopy, energy-dispersive x-ray spectroscopy) and evaluation of pore-size distribution (mercury intrusion porosimetry). In addition, macro-scale testing has been carried out to determine compression, flexure and durability response. Numerical simulations have been carried out to understand hydration of cementitious composites, determine optimum particle packing and determine the thermal performance of these composites. / Dissertation/Thesis / Doctoral Dissertation Civil, Environmental and Sustainable Engineering 2018

Due to climatic change, increasing thermal loads inbuildings and rising living standards, comfort cooling inbuildings is becoming increasingly important and the demand forcomfort cooling is expanding very quickly around the world. Theincreased cooling demand results in a peak in electrical powerdemand during the hottest summer hours. This peak presents newchallenges and uncertainties to electricity utilities and theircustomers. Cool thermal storage systems have not only the potential tobecome one of the primary solutions to the electrical powerimbalance between production and demand, but also shift coolingenergy use to off-peak periods and avoid peak demand charges.It increases the possibilities of utilizing renewable energysources and waste heat for cooling generation. In addition, acool storage can actually increase the efficiency of combinedheat and power (CHP) generation provided that heat drivencooling is coupled to CHP. Then, the cool storage may avoidpeaks in the heat demand for cooling generation, and this meansthat the CHP can operate at design conditions in most oftime. Phase Change Materials (PCMs) used for cool storage hasobtained considerable attention, since they can be designed tomelt and freeze at a selected temperature and have shown apromising ability to reduce the size of storage systemscompared with a sensible heat storage system because they usethe latent heat of the storage medium for thermal energystorage. The goal of this thesis is to define suitable PCM candidatesfor comfort cooling storage. The thesis work combines differentmethods to determine the thermophysical properties oftetradecane, hexadecane and their binary mixtures, anddemonstrates the potential of using these materials as PCM forcomfort cooling storage. The phase equilibrium of the binarysystem has been studied theoretically as well asexperimentally, resulting in the derivation of the phasediagram. With knowledge of the liquid-solid phase equilibriumcharacteristics and the phase diagram, an improvedunderstanding is provided for the interrelationships involvedin the phase change of the studied materials. It has beenindicated that except for the minimum-melting point mixture,all mixtures melt and freeze within a temperature range and notat a constant temperature, which is so far often assumed in PCMstorage design. In addition, the enthalpy change during thephase transition (heat of fusion) corresponds to the phasechange temperature range; thus, the storage density obtaineddepends on how large a part of the phase change temperaturerange is valid for a given application. Differential Scanning Calorimetery (DSC) is one frequentlyused method in the development of PCMs. In this thesis, it hasbeen found that varying results are obtained depending on theDSC settings throughout the measurements. When the DSC runs ata high heating/cooling rate it will lead to erroneousinformation. Also, the correct phase transition temperaturerange cannot be obtained simply from DSC measurement. Combiningphase equilibrium considerations with DSC measurements gives areliable design method that incorporates both the heat offusion and the phase change temperature range. The potential of PCM storage for peak shaving in differentcooling systems has been demonstrated. A Computer model hasbeen developed for rapid phase equilibrium calculation. The useof phase equilibrium data in the design of a cool storagesystem is presented as a general methodology. Keywords:Comfort cooling, peak shaving, PCM, coolthermal storage system, DSC, phase change temperature range,the heat of fusion, phase equilibrium, phase diagram. Language:English

In this thesis, the possible usage of phase change materials in military shelters with the aim of decreasing the heating effect of the solar radiation is presented. In order to meet the rapidly growing demand for energy in military applications, a passive cooling technique, specifically, storing thermal energy with phase change materials is analyzed by using experimental approach. Not only different types of phase change materials but also different amounts of them are examined during the solar loading experiments. In order to simulate solar heat loading on prototype military shelters, solar radiation test or in other words sunshine test that is stated in military standard MIL