Phase Change Materials In Buildings Research Articles

Multiobjective Optimization of Cement-Based Panels Enhanced with Microencapsulated Phase Change Materials for Building Energy Applications

Thermal energy storage using phase change materials (PCMs) is a promising technology for improving the thermal performance of buildings and reducing their energy consumption. However, the effectiveness of passive PCMs in buildings depends on their optimal design regarding the building typology and typical climate conditions. Within this context, the present contribution introduces a novel multiobjective computational method to optimize the thermophysical properties of cementitious building panels enhanced with a microencapsulated PCM (MPCM). To achieve this, a parametric model for PCM-based cementitious composites is developed in EnergyPlus, considering as design variables the melting temperature of PCMs and the thickness and thermal conductivity of the panel. A multiobjective genetic algorithm is dynamically coupled with the building energy model to find the best trade-off between annual heating and cooling loads. The optimization results obtained for a case study building in Sofia (Bulgaria-EU) reveal that the annual heating and cooling loads have contradictory performances regarding the thermophysical properties studied. A thick MPCM-enhanced panel with a melting temperature of 22 °C is needed to reduce the heating loads, while a thin panel with a melting temperature of 27 °C is required to mitigate the cooling loads. Using these designs, the annual heating and cooling loads decrease by 23% and 3%, respectively. Moreover, up to 12.4% cooling load reduction is reached if the thermal conductivity of the panels is increased. Therefore, it is also concluded that the thermal conductivity of the cement-based panels can significantly influence the effectiveness of MPCMs in buildings.

Thermal storage performance of eutectic sugar alcohols applied to buildings and enhancement of crystallization

Sugar alcohols are suitable for compact and high-density building thermal energy storage systems because of the high enthalpy, low price, and non-toxicity. But most sugar alcohol materials have severe supercooling characteristic, which limits their application as phase change materials (PCMs) in thermal energy storage systems. In this study, xylitol, sorbitol, erythritol, mannitol and dulcitol were selected as PCMs. Based on the five single sugar alcohols, ten multicomponent eutectic sugar alcohols were obtained which melting temperatures is between 60 °C and 90 °C applied to buildings. The thermal parameters of sugar alcohols were tested by differential scanning calorimetry (DSC), the supercooled eutectic sugar alcohols were stimulated by means of mechanical agitation to accelerate crystallization. The crystallization after excitation was monitored by microscope, and the supercooled crystallization phenomenon of eutectic sugar alcohols was investigated by isothermal phase change tests. The results showed that only three eutectic sugar alcohols could crystallize by stirring, and the melting temperatures of three eutectic sugar alcohols are about 80 °C. After multiple repetitive experiments, three eutectic sugar alcohols still have good crystallization characteristics. The results of the research provide a reference value in practical aspects for the design and selection of phase change materials in buildings.

Using PCM in buildings to reduce HVAC energy usage taking into account Saudi Arabia climate region

Primary energy consumption increased by 24.2% in the Middle East region from 2010 to 2020. This figure for Saudi Arabia was 40%. Therefore, Saudi Arabia's position in the Middle East is not acceptable in terms of energy consumption. In this study, by the addition of phase change materials (PCMs), the building HVAC power demand (PD) declined. Five climatic regions with an average annual temperature of 2–28.5 °C in Saudi Arabia were studied. These locations are classified as hot and dry due to the high intensity of the radiation (global intensity radiation of higher 2100 kWhm2.year). Six PCMs with melting temperature range of 21–32 °C was mounted to the envelopes and it was found that these materials lessen HVAC PD in each location. In the third region, PCMs were not useful in winter due to ambient temperature conditions. In the summer, all six substances dramatically weakened the HVAC PD. Finally, focusing on annual analysis, the best performance was given to A27 and A29 PCMs. In all regions except the second location, PCM A29 declined HVAC PD by 101.5 kWhm2, 84 kWhm2, 104 kWhm2 and 93 kWhm2 for locations of 1, 3, 4 and 5. For location 2, A29 was named the best taking into account HVAC PD reduction by 102.6 kWhm2.

A review on phase change materials (PCMs) for thermal energy storage implementations

With the rapid developments in the industry and technology, the energy need is increasing. 80% of the CO2 emission in the atmosphere is caused by the use of fossil based fuel and this situation has a serious impact on climate change. Therefore, energy researchers/engineers mainly work on the development and improvement of the techniques in order to use renewable energy sources more effectively. In this context, intensive studies have been carried out in order to use the energy from the sun in the most efficient way, by active or passive means when it is needed. Because solar energy is a discontinuous energy source within day and seasons, its storage in thermal form is one of the commonly used techniques. The most effective and easiest way to achieve this is to exploit from phase change materials (PCM) directly or by developing them as a composite. In this context, PCMs are used in various research areas of energy storage and thermal management systems. Since, particularly, approximately 40–45% of the energy consumption in the world is corresponding to the consumed amount for heating, cooling and air conditioning in buildings, the use of PCMs in buildings directly or by integrating them with building materials makes them more important in terms of energy saving. For this purpose, the number of studies on the use of effective phase change materials (PCMs) that have the ability to store/release solar energy in the form of latent heat is increasing. In this short review, general information about PCMs that can passively store thermal energy is presented. The diversity of PCMs, the selection criteria in practical applications, the difficulties of use, the solvation ways and also their potential utility areas were summarized.

Climate-Based Analysis for the Potential Use of Coconut Oil as Phase Change Material in Buildings

One of the most efficient measures to reduce energy consumption in buildings is using passive thermal comfort strategies. This paper shows the potential of coconut oil as a bio-based phase change material (PCM) incorporated into construction components to improve the thermal performance of buildings for several climates, due to its environmental advantages, wide availability, and economic feasibility. The thermophysical properties of coconut oil were determined through differential scanning calorimetry. Numerical simulations were conducted in ESP-r, comparing an office space with a gypsum ceiling to one with coconut oil as PCM for 12 climate types in the Köppen–Geiger classification. The results show that coconut oil is a suitable PCM for construction applications under tropical and subtropical climates. This PCM can provide year-round benefits for these climates, even though a higher melting point is needed for optimum performance during hotter months. The highest demand reduction of 32% and a maximum temperature reduction of 3.7 °C were found in Mansa, Zambia (Cwa climate). The best results occur when average outdoor temperatures are within the temperature range of phase change. The higher the diurnal temperature range, the better the results. Our findings contribute to a better understanding of coconut oil in terms of its properties and potential for application in the building sector as PCM.

Experimental Investigations for Thermal Energy Management by Encapsulation of Nano -Enhanced Bio Phase Change Material in buildings

ABSTRACT Due to the enormously increasing population in metropolitan cities of India, most of the transmissions of ozone exhausting substances are expected from metropolitans, of which the building structures may contribute significantly. To limit these levels, one of the inevitable structures of the metropolitan plan is to adopt green buildings. In this regard, integration of Nano-enhanced Bio Phase Change Material (NeBPCM) in buildings is an innovative technology that has a high potential to reduce the thermal energy penetration into the buildings, The green buildings enhance the thermal comforts inside the building with energy conservation. A novel integration of NeBPCM composite is introduced to a Solid Concrete Hollow Block of size 400 mm x 200 mm x 100 mm. The experimental building of size 1 m x 1 m x 1 m is constructed to analyze the thermal effects of this phase change material (PCM) integration within the buildings. A drop in temperature is observed in PCM integrated building from 5.3°C to 1.1°C compared to that of building without PCM. The error between the measured data and numerical predictions is found to be within the range of 0.3°C and 1.6°C. The experimental investigations also revealed a reduction in maximum room temperature up to 5.3°C in the building integrated with NeBPCM vis-à-vis building without NeBPCM. Also, NeBPCM integration in building increased the temperature by 1.8°C when the outside ambient temperature averagely dropped below 23.6°C, thus improving the thermal comfort in the buildings all over the seasons. Therefore, NeBPCM integration in buildings is advantageous in terms of maintaining the room temperature to provide passive cooling of buildings with energy savings.

Experimental Study on the Use of Enhanced Coconut Oil and Paraffin Wax Phase Change Material in Active Heating Using Advanced Modular Prototype

The use of phase change materials in buildings as a thermal energy storage system gained the attention of researchers all over the world. In the current study, coconut oil bio-based PCM is macro-encapsulated with enhanced thermal conductivity containers and coupled with hydronic radiant floor heating system. The study follows experimental aspect utilizing two identical small scale modular test prototypes. Investigations are directed toward studying the effect of the active CO-PCM system under different weather conditions, effect of combining active and passive systems, effect of PCM choice/type and effect of PCM location within the active floor, on the thermal and energy storage performances. Results revealed that coupling CO-PCM to active floor, passive wall and passive roof is capable of achieving load shifting and energy savings; and is affected by the control method, weather conditions, electricity tariff policy and PCM position and type. Further discussions, conclusions and perspective recommendations are summarized within the article.

Uso de PCM para edificações em região de clima quente

O consumo mundial de energia continua a crescer e tem se mostrado crítico quanto ao uso de sistemas de refrigeração em países de clima quente. O desempenho térmico da envoltória do edifício exerce considerável influência nas condições ambientais internas e no conforto do usuário. Esse artigo tem como objetivo identificar, selecionar, avaliar e sintetizar informações sobre o uso de PCMs (materiais de mudança de fase) em edificações em países de clima quente como estratégia para um bom desempenho térmico, por meio de uma Revisão Sistemática da Literatura (RSL). Enfatiza-se os tipos de materiais, seus critérios de seleção e formas de incorporação e aplicação, assim como, identifica-se lacunas e tendências de pesquisa. A escolha do tema deve-se à observância de uma tendência de pesquisas internacionais voltadas para o uso de PCM em edificações por meio de uma análise prévia de artigos. Os artigos mapeados pela RSL demonstraram o grande potencial que os PCMs têm na redução do consumo energético das edificações em países de clima quente. A partir das discussões é possível reforçar a ideia de que os parâmetros climáticos e as propriedades termofísicas do PCM são essenciais nas escolhas de projeto, entretanto ênfase igual deve ser dada a estratégias passivas que podem atuar em conjunto, além da disponibilidade do material e dos recursos financeiros, bem como os objetivos de interesse. Reforça-se o princípio de que cada projeto é único, mas que os resultados podem servir como referência inicial para outras análises.

Mechanical and Thermo-Physical Performances of Gypsum-Based PCM Composite Materials Reinforced with Carbon Fiber

Phase change materials (PCMs) have received extensive attention due to their high latent heat storage density and isothermal behavior during heat charging and discharging processes. The application of PCMs in buildings would match energy supply and demand by using solar energy effectively, thereby reducing building energy consumption. In this study, a diatomite/paraffin (DP) composite was prepared through a vacuum-impregnated process. The thermo-physical performance, thermal stability, chemical structure and thermal reliability of the DP composite were evaluated. To develop a structural–functional integrated energy storage building material, carbon fibers (CF) were chosen as the reinforcing material. The mechanical and thermal properties of CF-reinforced DP/gypsum were examined. It is evident that the flexural strength and thermal conductivity of DP/gypsum containing 1 wt. % CF increased by 176.0% and 20.3%, respectively. In addition, the results of room model testing demonstrated that the presence of CF could enhance the overall thermal conductivity and improve the thermo-regulated performance of DP/gypsum. Moreover, the payback period of applying CF-reinforced DP/gypsum in residential buildings is approximately 23.31 years, which is much less than the average life span of buildings. Overall, the CF reinforced DP/gypsum composite is promising for thermal energy storage applications.

A review on phase change materials for different applications

Phase change materials (PCMs) are preferred in thermal energy storage applications due to their excellent storage and discharge capacity through melting and solidifications. PCMs store energy as a Latent heat-base which can be used back whenever required. The liquefying rate (melting rate) is a significant parameter that decides the suitability of. PCMs in applications where there is a notable difference in temperature within the device for discontinuous warm storage capacities. A few studies have also been conducted to integrate PCMs in buildings as it upgrades building warm idleness, decreases maximum heat flux. This review paper summarizes some of the applications of PCMs. For future developments, some of the recommendations can be summarised as: in few of the listed applications, stability of the PCM needed to be explored since very few literature are available. The use of multiple phase change materials in a coupled or conjugate applications may also be further explored. In these applications, cost analysis and payback period of thermal storage systems empolyed with phase change materials also need exploration.

Experimental investigation of an energy saving system using Phase Change Materials in buildings

In this paper, experimental research has been conducted intended for using Phase Change Materials (PCM) by incorporating it with the building layers walls. The effect of involving PCM volume ratio and orientation on the thermal efficiency and thermal comfort was experimentally studied. Two identical rooms models have been constructed. The first model was used as a standard room as a reference one without using PCM and the second model has the PCM layers and used for all experimental testing works. Both rooms are installed at National Research Center, NRC, Giza, 30.08° N latitude, Egypt. The PCM used in this experimental work was paraffin wax having a melting point of 29 °C. Many cases have been studied based on the south wall, east wall and west wall respectively. It is found that using PCM caused a considerable reduction in the indoor air temperature and consequently reduction in the cooling load that minimizes the building energy consumed. It is concluded that the Percentage of the cooling load reduction of the zone by using PCM and according to cases and for peak hour in day was 19.2 % with PCM for East, West and South walls together, followed by 16.8 % for South wall only, followed by 12.7 % with West wall only and followed by 10.5 % for East wall only. It is found that the best case in cooling load reduction of the room for peak hours of PCM for South, West and East walls together by 19.2 %. The experimental results of the present study were validated with the corresponding experimental study of Mushtaq 2018 with a considerable agreement between the daily cooling load reduction per space volume and the cooling load reduction ratio. It is known that the cooling load reduction ratio is referred to the energy-saving which proved that using PCM in the building will contribute to energy saving in residential building

ENERGY AND FEASIBILITY ANALYSIS OF APPLYING BIO-BASED PHASE CHANGE MATERIALS TO BUILDINGS IN EAST ASIA

ABSTRACT The application of phase change materials (PCMs) in building envelopes can help promote energy efficiency due to its high heat capacity. Our study aimed to provide energy and economic insights for deploying PCM to buildings in eight different regions of East Asia through a series of energy and economic analysis using computer modelling and simulations. The static payback period (SPP) and dynamic payback (DPP) methods were used to evaluate the economic feasibility of applying a PCM at different melting phase temperatures (20°C, 23°C, 25°C, 27°C and 29°C). Results show that the proper choice of a PCM melting temperature is a key factor to improve the performance of the PCM applied to buildings. A melting phase temperature of 29°C achieved the highest economic feasibility in Seoul, Tokyo; Pyongyang; Beijing; and Ulaanbaatar and a melting temperature of 23°C in Hong Kong had the highest economic feasibility. Overall, the combined economic and energy analysis presented in this study can play an important role in improving the energy and economic feasibility of PCM in buildings.

Energy saving application of phase change materials in buildings: A comprehensive review

The theoretical basis of the preparation of phase change energy storage materials is analyzed firstly, and then the preparation methods of fatty acid phase change energy storage materials are analyzed in detail. Furthermore, the application of phase change energy storage materials in building energy saving is analyzed. Finally, combined with the above contents, the application prospect and research direction of phase change energy storage materials are briefly described.

Study of a novel ceramsite-based shape-stabilized composite phase change material (PCM) for energy conservation in buildings

Building envelope with phase change material (PCM) embedded is able to optimize the thermal utilization and reduce energy consumption in buildings. However, the leakage of molten PCM, the low thermal performances (latent heat and thermal conductivity) and the inappropriate melting temperature limit the application of PCM in buildings. This work aims to propose a novel shape-stabilized composite PCM with encouraging thermal performances and effective encapsulation for applying to the building envelope. Firstly, a binary PCM with appropriate thermal properties for buildings was studied by using lauryl alcohol, stearic acid and nanoparticles, marked as LA-SA/Al2O3. Then this prepared LA-SA/Al2O3 was absorbed into ceramsite and encapsulated by styrene-acrylic emulsion and dry cement powder for shape-stability, a ceramsite-based PCM (LA-SA/Al2O3/C) was formed. Finally, the thermal-physical performances of the mixture of LA-SA/Al2O3/C and concrete were tested. The thermal performances of LA-SA/Al2O3 and LA-SA/Al2O3/C were measured by differential scanning calorimetry (DSC), the chemical and thermal stabilities were tested by Fourier transform infrared (FT-IR) and thermogravimetric (TG). Results show that the optimal proportion for LA-SA/Al2O3 is 82 wt% LA + 18 wt% SA with 0.5 wt% Al2O3 nanoparticle, for which the melting temperature and latent heat are 21.3 °C and 205.9 kJ/kg respectively. The LA-SA/Al2O3/C has the ability to prevent the leakage of PCM, owning the excellent melting latent heat of 133.4 kJ/kg, which is relatively high comparing with the values in other references. The concrete based-CPCM with 15% LA-SA/Al2O3/C embedded shows satisfied mechanical performance and has great potential to reduce the indoor temperature fluctuation caused by outdoor ambient, and cut down the energy consumptions of heating and cooling devices in buildings.

Adjustable insulation for enhancing the performance of phase change materials in buildings

Adjustable insulation for enhancing the performance of phase change materials in buildings

Analytical model to study the heat storage of phase change material envelopes in lightweight passive buildings

Integrating phase change materials (PCMs) into building envelopes can improve the heat storage ability of buildings and prevent overheating when the outdoor air temperature and solar radiation are high. However, simply adding a PCM to a building does not ensure that the temperature of a room can be controlled; hence, a suitable design method is necessary. Nevertheless, the heat storage mechanism of PCM envelopes is very complicated because it is affected by several factors, including the climate, building parameters, and the properties of the PCM employed. This study develops a mathematical model for passive buildings, and the factors affecting the heat storage process of PCM envelopes in summer are analyzed to determine an efficient method to control the temperature of the room with PCMs. A theoretical analysis demonstrates that PCMs reduce the indoor temperature, but not the average room temperature. The effectiveness of PCMs in buildings is influenced by both climate and building parameters. If the average outdoor air temperature is higher than the boundary of the humans' comfort level, overheating will occur even when using PCMs. Before using PCMs, the average room temperature should be calculated and previewed using the proposed theoretical model. If the effectiveness of PCM is limited, the average room temperature is reduced via ventilation.

The potential of phase change materials in mitigating cooling load of buildings in UAE

Abstract Integration of phase change materials (PCM) into building elements is explored extensively in the last decade to reduce air-conditioning demand for indoor thermal comfort. The PCM could absorb and release thermal energy as latent heat in a narrow temperature range. Several experimental studies reported energy saving and indoor temperature drop in summer conditions. However, the matter is sparsely researched in the environment of the United Arab Emirates (UAE), a region of high heat flux throughout the year. The current research provides an overview of the integration of PCM in buildings for indoor thermal comfort and energy saving in the UAE. The research highlights the problems of building-integrated photovoltaics (BIPV), e.g. efficiency drop. The significance of the PCM application in the built environment and its research gap is highlighted by reporting all the previous findings on the topic including the application of PCM in glazing, concrete and BIPV.

Review on performance assessment of phase change materials in buildings for thermal management through passive approach

Abstract Latent heat energy storage (LHES) systems using phase change materials (PCMs) are well known for its excellent thermal energy storage and release during melting and solidifications respectively. PCMs can be efficiently deployed in applications where significant temperature difference exists in the system for intermittent thermal energy storage. Several research contributions has been made on integrating PCMs in buildings for thermal management, as it enhances building thermal inertia, reduces maximum heat flux, shifts peak energy demand, reduces temperature fluctuations of air, etc., owing to its isothermal behavior and high energy storage density during phase change. Results of several research articles reveal that incorporation of PCM in buildings could significantly improve indoor comfort conditions and reduce energy demand of Heating ventilation and air conditioning (HVAC) systems, provided appropriate PCM selection, encapsulation methods, location deployed etc. This review paper is devoted to elucidate various facts attributing PCM integration in buildings for thermal management through passive approach. The facts includes performance of PCMs in buildings in terms of heat gain reduction, temperature attenuation, peak energy demand shifting and energy saving potential, encapsulation deployed, are discussed and presented in order to expedite the interpretation for future researchers, who took their research work in the field of building thermal energy management.

Passive cooling through phase change materials in buildings. A critical study of implementation alternatives

Global warming is gradually increasing the cooling energy demand of buildings. Phase change materials (PCM) offer high potential to passively reduce cooling energy consumption and overheating by absorbing heat gains in the daytime through their melting process, and releasing the heat at night while solidifying by taking advantage of free cooling through natural ventilation. However, the effectiveness of PCM-based solutions highly depends on the implementation techniques, material properties, environmental conditions and occupants’ behaviour. This paper analyses the performance of PCM-based solutions towards passive and low-energy cooling through a parametric study carried out in TRNSYS, in order to identify main design criteria for their optimal implementation. Two PCM implementation alternatives are assessed: a conventional passive application based on a PCM layer attached at the ceiling in contact with the indoor space, in which the heat transfer between PCM and air is based on natural convection; and an optimised low-energy application designed as a PCM layer integrated inside the suspended ceiling, in which the air flow is forced by a fan to enhance the heat transfer between PCM and the air. Both solutions are studied with and without the simultaneous operation of air-conditioning systems. A dwelling in a multi-family building was selected as a reference scenario. The results show that in the scenario with no participation of air-conditioning systems, the optimised PCM-based solution could reduce discomfort hours by 65% regarding the adaptive comfort model, and up to 83% through additional improvements in order to increase the heat transfer between PCM and air. On the other hand, the simulations reflect that both PCM-based solutions do not provide benefits in scenarios with an intermittent operation of air-conditioning systems. This study concludes with design criteria and strategies for an optimal implementation of PCM towards low-carbon buildings.

Effect of phase change material integration in clay hollow brick composite in building envelope for thermal management of energy efficient buildings

The present trend in building research is to improve sustainability in building construction and operation. The development of new renewable technologies is essential to improve the sustainability and to reduce emissions. The incorporation of phase change materials in buildings is an effective way to reduce the room temperature fluctuations and cooling loads/heating loads. Although several works have been carried out in this field, a novel phase change material clay hollow-brick composite has been used in this work. This article discusses the research on investigating the thermal performance of phase change material integration in building walls. Two identical test rooms (3 m × 3 m × 3.65 m) were constructed to study the effect of phase change material integration in buildings. The experimental buildings were constructed for the warm and humid weather conditions of Chennai city, India. Phase change material integration in the building wall is beneficial for reduction of room temperature and provides passive cooling of the building. The temperature drop in a phase change material room compared with a non-phase change material room varies from 6°C to 2°C, during various months of the year. DESIGNBUILDER simulation was carried out for phase change material and non-phase change material buildings during the months of January, March, May, and July. The simulated room temperature variation follows the same pattern in these months.