Thermal Energy Storage In Buildings Research Articles

The Regulation of Temperature Fluctuations and Energy Consumption in Buildings Using Phase Change Material–Gypsum Boards in Summer

This study examined the thermal performance of Comfortboard23, a commercial gypsum board from Knauf infused with phase change material (PCM). Structural characterization using XRD and SEM confirmed the presence of microencapsulated PCM within the gypsum matrix. The study does not provide a direct comparison between Comfortboard23 and other PCM-integrated gypsum boards on the market. This is a limitation of the research. A comprehensive comparison would involve testing multiple products under identical conditions, and evaluating factors such as thermal performance, cost-effectiveness, durability, and ease of installation. Thermal characterization involved a novel low-scale thermal chamber to measure U-value, thermal conductivity, heat storage capacity, and dynamic thermal response. Results showed incorporating PCM decreased the U-value by 2% compared to standard gypsum boards. Additionally, PCM inclusion increased heat storage capacity by around 45% and improved dynamic thermal characteristics by decreasing thermal stability coefficient from 0.92 to 0.76 and increasing thermal lag from 0.27 to 0.49 h. The 45% increase in heat storage capacity of Comfortboard23 could lead to a 10–20% reduction in heating and cooling energy consumption, improved thermal comfort, and potential HVAC downsizing. Exact benefits depend on climate, building design, and occupancy patterns, necessitating further research in diverse real-world settings. The findings demonstrate Comfortboard23’s potential for enhancing thermal energy storage in buildings, contributing to energy savings, improved thermal comfort, and reduced temperature fluctuations across varying daily temperatures. Overall, the study highlights the promise of Comfortboard23 as an energy-efficient PCM-integrated building material.

Assessment of Physico-Chemical Behavior and Sorptivity-Diatomaceous Earth as Support for Paraffinic Phase-Change Materials.

Diatomite's most common application is its use as a sorbent for petroleum substances. Since paraffin is a petroleum derivative, this paper investigates the sorption capacity of diatomite to absorb it. In this paper, the physical and chemical properties were studied for 4 different fractions of diatomite (0-0.063 mm; 0-2 mm; 0.5-3 mm; and 2-5 mm) in the crude and calcined states, and the sorption capacity of diatomite earth for absorbing paraffinic phase-change substances was determined. The physical and chemical studies of the material included conducting an oxide chemical composition analysis using XRF, examining the composition of the mineral phases using X-ray diffraction, and determining the particle size, porosity, and thermal conductivity of the diatomite. Morphology images were also taken for all 8 diatomite variants using scanning electron microscopy. Each fraction was subjected to static calcination at 850 °C for 24 h. The results showed that the calcination of the diatomite increased the porosity of the material and reduced the thermal conductivity coefficient, and most importantly, the sorption capacity to absorb paraffins. The highest sorption capacity was characterized by calcined diatomite powder, that is, diatomite with the smallest particle size. Absorption of paraffinic substances by diatomite exceeding 200 wt.% is possible. Thus, diatomite is one of the feasible candidates for an economical and lightweight building material for making PCM composites for thermal energy storage in buildings.

Characterisation of the COMFORTBOARD gypsum board for thermal energy storage in buildings

Currently, the construction sector contributes considerably to the total energy consumption and greenhouse gas emissions into the atmosphere. Thermal energy storage (TES) systems are alternatives to increase the thermal inertia of buildings, aiming to use less energy, improve thermal comfort and reduce temperature fluctuations of interior spaces. One of the possible applications in buildings is to increase their thermal mass by impregnating phase change materials (PCM) in porous construction materials, e.g., gypsum boards. In this investigation, a commercial gypsum board impregnated with PCM (Knauf Comfortboard – BASF) was investigated by carrying out a structural and thermal characterisation. The thermal response obtained agrees with the product's technical data sheet provided by the supplier. The results of the thermal characterisation show that the inclusion of PCM in the gypsum board decreased the U-value by 2 % compared to the control sample (no PCM), increased the heat storage capacity by around 45 %, improved the thermal dynamic characteristics of the material by decreasing the thermal stability coefficient from 0.92 to 0.76 and increasing the thermal lag from 0.27 to 0.49 h. Our results sustain the potential application of commercial gypsum boards with PCM under environmental conditions across a wide range of daily temperature fluctuations (e.g., The North of Chile).

Enhancing thermal energy storage in buildings with novel functionalised MWCNTs-enhanced phase change materials: Towards efficient and stable solutions

Phase change materials (PCMs) are a promising panacea to tackle the intermittency of renewable energy sources, but their thermal performance is limited by low thermal conductivity (TC). This pioneering work investigates the potential of organic PCM-enriched surface-modified and un-modified multi-walled carbon nanotubes (MWCNTs) for low-temperature thermal energy storage (TES) applications. The functionalised and un-functionalised MWCNTs enhanced PCM have demonstrated a TC enhancement of 158 % and 147 %, respectively, at 25 °C. However, the TC value of the unmodified MWCNTs-based PCM dropped by 52.5 % after 48 h at 25 °C, while that of the functionalised MWCNTs-based PCM remained stable. A DSC analysis of up to 200 thermal cycles confirmed that the surface-modified and un-modified MWCNTs had no major effect on the peak melting and cooling temperatures of the nano-enhanced PCMs although a minor decrease of 7.5 % and 7.7 % in the melting and crystallisation enthalpies, respectively, was noticed with the inclusion of functionalised MWCNTs. Moreover, functionalised MWCNTs incorporated PCMs have led to increases in specific heat capacity by 23 % with an optimal melting enthalpy value of 229.7 J/g. In addition, no super-cooling, no phase segregation, and a small phase change temperature were noticed with these nano-enhanced PCMs. Finally, no chemical interaction from nano-PCMs was seen in the FT-IR spectra with the incorporation of both functionalised and un-treated MWCNTs. It is evident that the functionalised MWCNT-based PCM has better thermal stability and it offers a promising alternative for improving thermal storage and management capabilities in buildings, contributing to a sustainable and energy-efficient building design.

Thermal energy storage in buildings: opportunities and challenges

Thermal energy storage in buildings: opportunities and challenges

Experimental analysis of clay bricks incorporated with phase change material for enhanced thermal energy storage in buildings

This study analyses the effect on thermal performance of clay bricks integrated with two different PCM using macrocapsules of different shapes. Tubular shape, square shape, and rectangular shape of macrocapsules were used to integrate PCM loaded with 20 wt% graphite and without graphite in the bricks. Thermal behaviour of all the bricks was investigated under real tropical environment for three consecutive days. Various parameters such as peak temperature, thermal amplitude, time lag, decrement factor, and heat transfer rate were investigated. Additionally, reduction in cooling load and corresponding cost savings in energy was also evaluated. Peak temperature reduction from maximum 9.87 % to minimum 1.81 % was observed in all the PCM bricks in comparison to conventional brick. Tubular encapsulated PCM brick without graphite has shown maximum reduction of 33.33 % and 33.20 % for day 1 and day 2 in thermal amplitude followed by square encapsulated PCM brick without graphite of 27.43 % for day 3. A maximum cooling load reduction of 23.66 % was observed in tubular shape encapsulated bricks without graphite and minimum cooling load reduction of 3.31 % was observed in rectangular shape encapsulated brick with graphite in comparison with conventional brick.

Integration of lauric acid/zeolite/graphite as shape stabilized composite phase change material in gypsum for enhanced thermal energy storage in buildings

The effectiveness of Gypsum plaster loaded with Shape Stabilized Composite Phase Change Material (SSCPCM) in regulating indoor temperature of the building is experimentally investigated in this study. SSCPCM is composed of Gypsum/Lauric acid/Zeolite loaded with varying percentage of Graphite (0 wt%, 5 wt%, and 10 wt%). The SSCPCM-0, SSCPCM-5, and SSCPCM-10 were characterized for morphology, physical structure, chemical structure, thermal energy storage capabilities, thermal stability, and thermal conductivity using Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Fourier Transformation Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry, Thermo Gravimetric Analysis (TGA), and thermal conductivity meter respectively. The results suggest that SSCPCM have excellent surface morphology and shows good chemical, thermal and physical stability. Thermal energy storage capacity of 81.08 J/g, 74.02 J/g, and 54.30 J/g at thermal conductivity of 0.242 W/mK, 0.427 W/mK, and 0.774 W/mk were shown by SSCPCM-0, SSCPCM-5, and SSCPCM-10 respectively. Additionally, SSCPCM-5 has shown superior thermal reliability by maintaining the thermo-physical characteristics after 1000 thermal cycles. These SSCPCMs were used to prepare GPCM, GPCM-5, and GPCM-10 composite gypsum plaster and five day real outdoor testing was conducted by applying them on indoor roof and south wall of cubicles. GPCM has effectively improves the indoor temperature profile in comparison with GPCM-5 and GPCM-10.

Demand response with active phase change material based thermal energy storage in buildings

A large potential to shift the electricity consumption to adapt to the stochastic renewable electricity generation is identified through the utilisation of a combination of Heat Pumps (HP) and local Thermal Energy Storage (TES) devices in building heating systems. In this paper, a building heating system coupled with an active Phase Change Material (PCM) TES device and a HP is simulated to characterise its potential for Demand Response (DR) applications. A control-oriented numerical model for the PCM TES is developed and previously validated numerical models of the building, HP and hot water radiators are integrated to simulate the dynamics of the coupled building heating system. A Genetic Algorithm (GA) based control strategy is designed to optimise the building heating energy consumption and operational cost with respect to time-varying electricity price signals. The developed control strategy is successfully implemented to utilise the TES capability of the PCM and the thermal inertia of the building to intelligently shift the electrical load of the HP to low price periods, while satisfying the specified indoor comfort requirements. In comparison to a reference case utilising a sensible TES, cost savings and consumption reductions of more than 40% and 30%, respectively, are attained with the active PCM TES. Simulation results indicate that utilising an active PCM TES over a sensible TES offers significant advantages for DR applications in building heating systems in terms of load shift flexibility, energy costs and consumption.

Performance improvement of lauric acid-1-hexadecanol eutectic phase change material with bio-sourced seashell powder addition for thermal energy storage in buildings

Organic phase change materials (PCMs) such as fatty acids and fatty alcohols are often trapped by inherent low thermal conductivity for thermal energy storage in buildings. The present study is devoted to ameliorating this problem from an innovative perspective of introducing bio-sourced additive. To promote performance of binary eutectic PCM comprising lauric acid (LA) and 1-hexadecanol (HD), the composite PCMs are developed, where the powdered seashell waste is added as thermal enhancer, and their thermo-physical properties are characterized via DSC, FT-IR, SEM, TGA, cooling curve analysis, accelerated thermal cycling test together with thermal conductivity measurement. Meanwhile, the impacts of two particle sizes, five mixing ratios between two different sizes and two modification approaches of seashell powder (SP) are surveyed meticulously. Experimental results turn out that 80-mesh SP and 300-mesh SP are both capable of providing greater thermal conductivity when dispersed in LA-HD eutectic PCM, and the enhancement level of thermal conduction is even higher for composite PCM containing 300-mesh SP than for composite PCM containing TiO2 powder. Besides, the thermal conduction ability is strengthened to the maximum extent when 80-mesh SP and 300-mesh SP are combined at mass ratio of 3:7, while the same situation also occurs when seashell powder is treated by high-temperature calcination. The resultant composite PCM possesses encouraging melting temperature and melting enthalpy, and its thermal stability and reliability are well approved. Therefore, we conclude that the seashell powder has the expectable competence to realize performance improvement of organic PCM for application in buildings for thermal energy storage.

Thermal energy storage co-benefits in building applications transferred from a renewable energy perspective

Although one of the main aims of using renewable energy sources in building applications is to reduce the environmental impact caused by the high global energy demand of buildings, it can also produce other positive effects, known as co-benefits. Thermal energy storage technologies are often used in building applications, either integrated into the renewable system or independently, for energy savings or energy efficiency reasons. This paper demonstrates that it is possible to identify the co-benefits of the use of thermal energy storage in buildings by cross-sectorizing the renewable energy and thermal energy storage sectors. To this end, this article first reviews the literature on the co-benefits of renewable energy for building applications, followed by an evaluation on how these co-benefits can be attributed to thermal energy storage in buildings. As a result of a keywords analysis, the main co-benefits of thermal energy storage were identified related to environmental, health, economic, cost, and policies aspects.

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.

A novel dodecanol/tepexil PCM composite for thermal energy storage in buildings

Phase change materials for thermal energy storage through latent heat have been extensively investigated in the last decade for their high potential for heating and cooling purposes in buildings. This paper presents a novel composite PCM's thermophysical properties formed by dodecanol/tepexil and prepared by the vacuum impregnation technique. Although there have been some past studies on making PCM composites using dodecanol, their enthalpy values have not been as high as expected. Scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), laser flash analysis (LFA), differential scanning calorimetry (DSC), and T-History measurements were used to characterize the PCM composite. Dynamic T-History tests revealed that this PCM Dodecanol/Tepexil composite has a fusion temperature of 24.13 °C and a fusion enthalpy of 118 J g−1 and solidification temperature of 20.41 °C with a solidification enthalpy of 108.35 J g−1. These results are the highest values using impregnation techniques to date in the thermal comfort range that goes from 21 to 26 °C for a mild-tempered climate, where the mean temperature is about 22 °C and high annual thermal oscillations (where PCM or high thermal inertia materials are recommended), as far as the authors are concerned. The resulting thermal conductivity of the dodecanol/tepexil composite was 0.308 W m−1 K−1 at 30 °C. Tepexil particles of less than 250 μm exhibit an average pore size of 9.5, 36, and 250 nm and a BET surface area of 2.1 (m2 g−1). Leakage tests on the composite showed a maximum retention rate of 40% dodecanol. It was concluded that this PCM composite dodecanol/tepexil could be considered good candidate material with the potential for energy storage in building applications due to its thermal/chemical stability and high energy storage performance.

Characterization of Fly Ash Cenosphere – Capric acid composite as phase change material for thermal energy storage in buildings

ABSTRACT Energy demand in buildings has been steadily increasing in the recent past. The majority of energy is used to heat and cool the building envelope to maintain a conducive thermal environment for habitation. Integration of Phase Change Materials (PCM) in buildings has improved the structure’s energy efficiency by absorbing and discharging energy as latent heat. In this work, Cenosphere–Capric Acid (CeCA) composite PCM was developed by the technique of impregnating capric acid (CA) into the hollow core of the cenosphere (Ce) under vacuum followed by sealing it with SiO2. The morphology of the prepared CeCA composite was investigated by FESEM. Mineralogical characterization by XRD suggested that the mineral structure of the CeCA composite has remained unaltered. Phase change temperature and latent heat of CeCA composite were evaluated as 27.60°C and 69.07 J/g for melting and 23.16°C and 71.30 J/g for freezing, respectively. Thermo-Gravimetric Analysis (TGA) of CeCA indicated the enhanced thermal stability of the composite. CeCA composite indicated good chemical compatibility between Ce, CA, and SiO2; hence, the composite is chemically stable, as revealed by FTIR analysis. Accelerated thermal cycling of CeCA composite indicates a relatively modest change in phase change temperature of 0.6°C for melting and 0.1°C for solidification. Further characterization by TGA and FTIR, suggested that the CeCA composite is reliable for the long term. It implies that the CeCA composite has significant potential as a PCM for thermal energy storage application in construction materials and structures.

Development of a shape-stabilized phase change material utilizing natural and industrial byproducts for thermal energy storage in buildings

A comprehensive study was conducted to develop and utilize a novel shape-stabilized phase change material utilizing two abundantly available and low-cost natural materials, namely scoria and expanded perlite and an industrial byproduct, heavy oil ash, in combination with polyethylene glycol. The thermal and energy storage characteristics of the composite materials were evaluated with the aim of using them to conserve energy in the domestic facilities. The results of differential scanning calorimetry showed that expanded perlite composite has the highest melting and solidification latent heat values, 150.7 J/g and 134.6 J/g, respectively, compared to scoria and oil ash composite. However, expanded perlite composite has lower thermal conductivity compared to other composites. Consequently, a novel system incorporating carbon nano tubes (0.5 wt.% and 1 wt.%) in the expanded perlite composite was developed to improve its thermal conductivity. The thermal conductivity (0.453 W/m.K) of the new system with 0.5% carbon nano tubes is remarkably more than that of commonly used phase change materials. Further, the developed PCM with 0.5% carbon nano tubes can transform sunlight into thermal energy with a solar-to-thermal energy conversion efficiency of 59.4% and it has a thermal conductivity that is 97% more than that of polyethylene glycol alone. Besides, the newly developed PCM also shows excellent energy storage and release performance. All these favorable characteristics indicate that the developed phase change material can be beneficially utilized in thermal storage systems.

Correction: Addressing energy storage needs at lower cost via on-site thermal energy storage in buildings

Correction for ‘Addressing energy storage needs at lower cost via on-site thermal energy storage in buildings’ by Adewale Odukomaiya et al., Energy Environ. Sci., 2021, 14, 5315–5329, DOI: 10.1039/D1EE01992A.

Performance Improvement of Lauric Acid-1-Hexadecanol Eutectic Phase Change Material with Bio-Sourced Seashell Powder Addition for Thermal Energy Storage in Buildings

Performance Improvement of Lauric Acid-1-Hexadecanol Eutectic Phase Change Material with Bio-Sourced Seashell Powder Addition for Thermal Energy Storage in Buildings

Thermo-regulating performance of concrete slab loaded with shape stabilized phase change material in tropical climate

The building overheating problem is one of the most important problems facing all over the world. Various methods like using highly thermal resistive building materials, composite building materials were used to reduce the heat gain of the buildings. One of the method which can be used in place of traditional methods is using building elements with high thermal energy storage capacity. The significance of this study is to improve the thermal energy storage capacity of the building element for improving indoor thermal performance of the building. In this study latent heat energy storage capacity of the concrete slab is enhanced by incorporating Shape Stabilized Phase Change Material (SS-PCM) in it. SS-PCM was prepared by incorporating eutectic PCM (Paraffin Wax 70% and Coconut Oil 30%) in highly porous material called zeolite. The zeolite powder successfully incorporate 30 wt% PCM without showing any leakage at elevated temperature. Morphology of the SS-PCM was evaluated through Scanning Electron Microscopy (SEM) images. The SS-PCM at 0 wt%, 10 wt%, 20 wt%, and 30 wt% was used to prepare composite concrete slab by replacing fine aggregates. Composite concrete slabs were tested for indoor thermal behavior in real outdoor testing of 72 h. Indoor thermal performance was evaluated on the basis of peak temperature reduction, thermal amplitude, time delay, and decrement factor. The 30% SS-PCM has a high latent heat capacity, which significantly improves thermal energy storage in buildings. Various parameters like peak temperature reduction, time lag, thermal amplitude and decrement factor were evaluated. Concrete slab integrated with 30% SS-PCM shows maximum peak percentage temperature reduction of 10.04 % and percentage reduction in thermal amplitude of 23.71 % in comparison to conventional concrete. Additionally, infrared thermography of all the concrete slabs at different time of the day was done.

Experimental investigation of clay brick with sensible, latent, and hybrid thermal energy storage in buildings

Global warming has caused uneven extremities in the climate such as heat waves, floods, and extreme rise in temperatures. Consequently, there is increase in demand for energy for indoor space cooling in the buildings to create better indoor thermal comfort. Thermal energy storage (TES) using Phase Change Material (PCM) is an effective technology for improving the thermal performance of the building envelope. Energy efficient building envelope can reduce the external heat gain and maintains indoor thermal comfort level easily. In this study, the thermal performance of clay bricks integrated with sensible heat storage material, latent heat storage material, and hybrid (sensible + latent) was investigated. A comparative study of indoor thermal performance in terms of peak temperature, thermal amplitude, time lag, decrement factor of sensible heat storage brick, latent heat storage brick, and hybrid brick in comparison with conventional brick was prepared. Latent heat storage brick has shown the highest percentage average peak temperature reduction of 3.86 % in comparison to conventional brick. Maximum reduction of 13.74 % was shown by latent heat storage brick followed by hybrid heat storage brick and then by sensible heat storage brick. Time lag of 180 min is observed in brick embedded with latent heat storage capacity. Additionally, infrared thermal images suggest that the brick integrated with latent heat storage material shows better indoor thermal performance.

Study on thermal energy storage properties of bio-based n-dodecanoic acid/fly ash as a novel shape-stabilized phase change material

In the present study, a novel BSPCM was prepared with the n-dodecanoic acid (or) LA phase change material, which was vacuum impregnated into the porous FA pebbles. The surface morphology of the BSPCM has confirmed the presence of the lauric acid in the porous supporting matrix. The XRD analysis of the BSPCM revealed that the crystalline nature of the PCM was unaltered after impregnation. The surface structure study verified the chemical compatibility between the PCM and supporting material. The DSC results showed that, BSPCM has exhibited a good latent heat of fusion of 68.93 kJ/kg with high thermal energy storage capability of 97.62%. The BSPCM was thermally stable up to 150 °C and showed good leakage stability up to 85 °C. Thermal reliability of the BSPCM performed for 1000 thermal cycles revealed excellent thermal reliability index of 96.76%. Further, thermal conductivity of BSPCM was found to be 0.1702 W/mK, which was attributed to the effective impregnation of the PCM into the fly ash pebbles. In total, the developed BSPCM can be a viable candidate for achieving passive thermal energy storage in buildings.

Thermal performance of mortars/concretes containing calcined marl as alternative pozzolan

The solutions to the increasing problem regarding the energy demand of the world have been expected from the building sector with their consumption of a high amount of energy. Producing environmentally friendly and energy-efficient blended cements and using materials with high thermal performance in terms of insulation and thermal energy storage in buildings are some of these solutions. Calcined marl at the optimum temperature is an alternative pozzolan for blended cement production. The main purpose of this study is to determine how the thermal performance and mechanical properties of mortar/concrete are affected by using calcined marl as alternative pozzolan. For this purpose, mortars/concretes containing calcined marl blended cements were produced. The calcined marl replacement ratios of blended cements were 0, 10, 30 and 50 wt.%. In the study, the strengths and thermal performances of mortars/concretes containing calcined marl blended cements were determined. The test results were compared among themselves and with each other. From the test results, it was concluded that the thermal performances of the mortars/concretes containing calcined marl blended cements could be improved up to 50% replacement ratio without compromising the strength of considered materials.