Improve Energy Performance Research Articles

Thermal energy storage systems using bio-based phase change materials: A comprehensive review for building energy efficiency

The construction industry has seen significant growth in energy consumption over the past few years, primarily due to the demand for heating and cooling in buildings. This increase in energy use presents considerable environmental and economic challenges, making reducing energy consumption in homes a critical issue for many countries. A promising approach to improving energy performance in homes while reducing CO2 emissions is integrating phase change material (PCM)-based thermal energy storage (TES) systems into building designs. This review focuses on using bio-based phase change materials (BPCMs) in TES applications, which could contribute to lower energy consumption in the construction sector. Recent advancements in BPCM technology indicate that these substances, derived from renewable resources such as paraffin and fatty acids, can achieve thermal storage capacities similar to traditional PCMs. BPCMs function like thermal batteries, absorbing, storing, and releasing thermal energy through phase transitions, typically between 20 °C and 30 °C. This process helps stabilize indoor climates and decreases reliance on mechanical heating and cooling systems. This article comprehensively assesses the properties, thermal performance, and applications of BPCMs in building materials. It also provides an essential evaluation of life cycle assessment (LCA) and financial feasibility. Its purpose is to guide the research, engineering, and policy communities in adopting practical applications for sustainable construction practices. Integrating BPCMs in TES structures is crucial for improving sustainability and energy conservation in the construction industry. This approach offers a viable pathway toward creating more energy-efficient buildings. Furthermore, a comparative analysis is provided, evaluating BPCMs along different varieties of section trade substances, inclusive of natural, inorganic, and eutectic alternatives. This analysis specializes in numerous crucial factors: price, energy performance, and environmental impact. The review addresses challenges such as heat transfer costs, compatibility with conventional building materials, and policy implications.

A Comprehensive Approach to Nearly Zero Energy Buildings and Districts: Analysis of a Region Undergoing Energy Transition

This paper explores the development of positive energy communities using Eordaia, Greece, as a case study. The approach combines building and district-level energy analysis to achieve nearly zero energy performance through retrofitting, district-level storage systems, and renewable energy technologies. A parametric analysis utilizing RETSCREEN Expert and EnergyPlan software determines the optimal mix of technologies based on technical and financial parameters, with Eordaia, a region in energy transition and part of the RESPONSE Horizon project, illustrating the practical benefits. It includes a neighborhood of 105 mixed-use properties and two municipal buildings where a range of renewable energy sources and energy efficiency measures are applied. Insulation, photovoltaic systems, LED lighting, predictive thermostats, and windows coated with nanotechnology are some of the key interventions considered. The findings show considerable reductions in CO2 emissions and energy use, with payback periods ranging from 8.7 to 9.6 years. This study underscores the value of district-level strategies over individual building retrofits, highlighting cost savings and improved energy performance. These findings offer valuable insights for urban planners and policymakers aiming to transform urban areas into sustainable, positive energy districts, supporting the EU’s 2050 net-zero emissions goals.

Prioritizing Energy Performance Improvement Factors for Senior Centers Based on Building Energy Simulation and Economic Feasibility

This study examined energy performance improvement factors by analyzing both energy performance and the economic impacts to reduce energy costs for senior centers. A fact-finding survey was conducted on 20 senior centers in a metropolitan area, identifying key energy improvement factors. Energy simulations of the buildings were performed using ECO2, an officially certified energy assessment program in Korea, comparing the energy requirements before and after the improvements. The energy demand, energy consumption, and floor area were analyzed, with the J, K, and S standard models selected based on the median values of these factors. To assess the impact of the improvements, blower door tests were conducted on two senior centers before and after window upgrades. Based on the ECO2 simulations and the blower door test results, improvement priorities were identified in the following order: windows, exterior walls, boilers, roofs, and doors. Finally, an economic feasibility analysis applied the construction and heating costs to the standard models. Over a 40-year period, only boiler improvements generated a net profit. Without government support, this study recommends prioritizing boiler upgrades when selecting energy performance improvements.

Comparative Study of an Energy Information System and Energy Management System According to ISO 50001

Energy management, especially in communities, is attracting growing interest but is often marred by confusion between the terms “energy information system” (EIS) and “energy management system” (EMS). This ambiguity hinders understanding of their uses and roles in improving energy performance. Our objective is to clarify these terms and their contributions to energy management. We used a mixed qualitative and quantitative approach to evaluate and compare the criteria of definition, objective, functionality, and role, as well as correlated elements, such as organizational structure, responsibilities, planning, and policy, according to the requirements of ISO 50001, in addition to criteria specific to the two systems. The study revealed differences in the roles of the EIS and the EMS, with a complementarity of 40% between the two systems depending on the positioning of the EIS in relation to the elements of the EMS process. The EIS plays a crucial role in facilitating the implementation of the EMS according to ISO 50001. This clarification contributes to a better understanding of the respective roles of these systems in energy management, thus helping communities to improve their energy performance in an effective manner.

Application of a decision tree approach to predict energy consumption in lightweight buildings under subtropical climate

PurposeLightweight building systems have emerged as alternatives to reduce the high environmental impact of conventional masonry. However, in subtropical climates, the low thermal inertia of lightweight envelopes negatively affects energy performance. The purpose of this paper is to investigate the thermophysical parameters that influence heating and cooling energy consumption in lightweight residential buildings under subtropical climates and develop a model to predict these parameters using statistical and machine learning tools.Design/methodology/approachA database was created with computer simulation data on the energy performance of 2048 building conditions generated by factorial combination of 10 parameters. Sensitivity analysis was performed to identify which parameters contribute most to energy performance indicators. Subsequently, decision trees were created using a classification and regression tree (CART) algorithm to visualize parameters and improve energy performance indicators, particularly cooling energy consumption.FindingsLow thermal transmittance and ground contact are interesting strategies for low thermal capacity buildings. Furthermore, the findings showed that relying only on the most influential properties does not ensure good energy performance; rather, it is the adequate combination of envelope properties that leads to good energy efficiency. The tree developed by CART can be used as a guide to assist designers and researchers in the initial selection of building envelopes, demonstrating the impact of each choice on electrical energy consumption for indoor climate control.Originality/valueBy adopting a global approach to assess the thermal performance of lightweight buildings, this study makes a significant contribution to synthesizing the results of a complex and time-consuming methodology into a guide for optimizing envelope design decisions and directing efforts and resources toward efficient strategies.

Appraising correlation between international organisation for standardisation 50001 and green productivity: A study of workers in Baiji, Iraq

Studies have shown that the progress and success of companies are achieved through their ability to improve energy performance and preserve the environment. It would translate to environmentally friendly products. However, there is a paucity of studies regarding the International Organisation for Standardisation (ISO) 50001 and its role in enhancing environmentally friendly products in developing countries such as Iraq. This study investigates the correlation between ISO 50001 standards and green productivity among Baiji's refinery workers in Iraq. Utilising a structured questionnaire, data from 128 respondents were analysed using descriptive and inferential statistics. Results indicate a significant positive correlation between ISO 50001 and green productivity, underscoring the importance of energy management training in enhancing productivity and environmental protection. As part of the study’s implications, it suggests increasing the company’s management’s attention to training in energy management and green productivity. Its positive impact on improving productivity and protecting the environment through continuous improvement of inputs, processes, outputs, and feedback to the company cannot be overstated.

Particle Swarm Optimization for multi-chiller system: Capacity configuration and load distribution

This study applies Particle Swarm Optimization (PSO) to enhance the energy efficiency of a multi-chiller system in a large office building, with a focus on optimizing capacity configuration and load distribution. Given the rising demand for sustainable energy solutions in buildings, where HVAC systems, particularly chillers, account for a significant portion of energy consumption, this research aims to reduce energy use and improve system performance. EnergyPlus simulations, based on Baltimore weather data and a reference large office model, were conducted to build a baseline dataset. This dataset was then used in Python to calculate energy consumption and optimize load distribution and capacity configuration. PSO was applied in three stages: optimizing capacity configuration using five built-in EnergyPlus algorithms, optimizing load distribution, and simultaneously optimizing both. The results showed that optimizing capacity configuration alone improved performance, even using traditional load distribution methods. Load distribution optimization outperformed other algorithms and converged at a 0.7 Part Load Ratio (PLR) for staging. The integrated PSO application achieved an 11.3 % reduction in energy consumption, a 21.5 % improvement in Coefficient of Performance (COP), and a 12.8 % increase in the Seasonal Energy Efficiency Ratio (SEER) by precise operation of 15 different combinations throughout the entire load range. These results demonstrate the potential of PSO to significantly enhance the efficiency of multi-chiller systems, providing a novel approach to optimizing both capacity configuration and load distribution. This research contributes to a robust framework for improving energy performance in building systems and offers valuable insights for future sustainable energy solutions.

Evaluation of the Energy Management System in Water and Wastewater Utilities in the Context of Sustainable Development—A Case Study

Energy management in enterprises is an important issue in the context of improving energy efficiency, energy use, and energy consumption. This is consistent with the Sustainable Development Goals. The purpose of this study was to evaluate the energy management system of water and wastewater utility in the context of sustainable development based on the opinions of managers and employees. The results indicate the involvement of the surveyed enterprise in energy management system development activity. This demonstrates the orientation of the surveyed enterprise to support activities to improve energy performance in line with the implementation of sustainable development. The added value is that the developed research tool can be used in studies of other enterprises to assess the level of energy management.

THE HOUSING UNITS OF THE POSITIVE CLIMATE NEIGHBORHOOD PEDRA BRANCA SC/BR

In response to the global climate crisis, urgent measures are required to reduce greenhouse gas emissions in alignment with the goals of the Paris Agreement. As energy consumption accounts for 36% of total emissions, and buildings contribute significantly to both direct and indirect emissions, it is crucial to enhance the energy efficiency and self-sufficiency of buildings. This article conducts a case study to evaluate the formal structure, spatial layout, and sustainable strategies employed in residential units within the Pedra Branca neighborhood (Santa Catarina, Brazil), using the methodology developed by Brandão and Schneider. The findings indicate that the housing units predominantly consist of three bedrooms, along with two to four bathrooms. The analysis revealed partial integration between the kitchen and service areas, with full integration being less common. Corridor layouts were found to make the greatest contribution to sustainability and internal space quality. Although some configurations did not directly support cross-ventilation, there was a clear focus on environmental comfort and the use of passive design strategies. This study highlights the potential of such configurations to improve energy performance and contribute to the development of climate-positive neighborhoods.

Numerical assessment of thermal bridging effects in 3D-printed foam concrete walls

Abstract Integrating smart technology and advanced materials in the construction industry has revolutionized traditional building practices, enhancing efficiency, sustainability, and overall performance. Researchers and professionals in the construction sector have shown significant interest in three-dimensional concrete printing (3DCP) for automating structural engineering tasks. Despite its potential as a sustainable solution to modern construction issues, there is a lack of research on the thermal insulation performance of three-dimensional printed concrete (3DPC) building envelopes, and the potential for integrating foam concrete (FC) to enhance energy efficiency has not yet been studied. This paper presents a numerical analysis examining how different infill geometries affect the thermal performance of 3D-printed foam concrete (3DPFC) lattice envelopes. Six lattice structures were designed with identical thickness, height, length, and comparable insulation areas. The effects of the contact (intersection) area of webs with the interior face shell, webs, and infill rows on the thermal performance of granularly insulated envelopes were studied. The effectiveness of insulation was also established. The findings indicate that the thermal transmittance of 3DPC envelopes correlates directly with the contact area of the webs and the interior surface, with U-values ranging from 0.151 W m2·K to 0.652 W/m2·K. Notably, the absence of direct connections between exterior and interior surfaces enhances insulation efficiency, with double-row structures achieving up to 94% insulation efficiency. However, when there is a direct connection between the two surfaces, the thermal performance of these envelopes is mainly affected by the contact (intersection) area of the webs with the interior face rather than the number of webs. By integrating foam concrete and double-row walls, this study demonstrates an innovative approach to reducing thermal bridging and improving energy performance in 3D-printed construction. The results offer novel insight into optimizing the thermal behavior of 3DPC systems for sustainable building practices.

Green Remodeling: Empirical Study of Thermal Insulation Improvement Remodeling of Public Healthcare Center

This study investigates the energy performance improvement in an aging public healthcare center in South Korea through a comprehensive “Green Remodeling” project. The building, originally constructed in 2001 before the establishment of national energy-saving standards, exhibited substandard insulation performance in its walls, roof, floors, and windows. The remodeling was designed to meet the highest current energy-saving criteria, incorporating advanced insulation techniques and energy-efficient systems. The remodeling process achieved a significant improvement in heating efficiency, with the ECO2 simulation predicting a 50% reduction in energy consumption. However, actual post-remodeling savings were approximately 10%, influenced by factors such as varying occupancy patterns and construction challenges. Despite these obstacles, the project demonstrated the effectiveness of targeted energy-saving measures in enhancing the overall performance of the building. This research underscores the importance of green remodeling as a viable strategy for improving energy efficiency in aging buildings, particularly in the context of South Korea’s carbon reduction goals. This study provides practical insights into the design and implementation of energy-saving technologies, offering a model that can be adapted for similar projects in other contexts.

Status and prospects of energy efficiency in the glass industry: Measuring, assessing and improving energy performance

The significant share of energy-related emissions in the glass industry necessitates robust energy efficiency strategies. This paper evaluates the status and prospects of energy efficiency by integrating the measurement, assessment, and improvement of energy performance through energy data and modelling. Measurement and assessment are crucial for effective energy management in hard-to-abate industrial sectors, providing insight into the existence and extent of potential energy efficiency gains. The use of appropriate performance indicators allows for comparison across production contexts and the monitoring of improvements achieved through interventions. The benchmarking of a representative sample of container glass furnaces reveals a current potential for improvement of around 10% based on alignment with best practices. Energy modelling is used to map energy flows along the various systems involved in production, thereby identifying major energy losses. Energy efficiency options can then be categorised based on their contribution to improving energy performance, facilitating the identification of solutions that address current bottlenecks. The study discusses promising opportunities arising from improved batch compositions and outlines the role of renewable penetration on the viability of hydrogen use and furnace electrification. The proposed approach can be transferred to other hard-to-abate industrial sectors to drive progress in decarbonisation.

Energy performance improvement for a mixed flow pump based on advanced inlet guide vanes

The sharp decrease in the efficiency of a mixed flow pump within over-load flow rates presents a challenge for coastal drainage pumping stations. To address this issue, two different structures of advanced inlet guide vanes (AIGV), full-adjustable (FA) and half-adjustable (HA) structures, are designed to approach a better energy performance improvement strategy. Entropy production theory is applied into transient flow field to reveal their influence mechanism on the spatial distribution of energy dissipation. The primary findings are as follows: (1) AIGVs effectively solve the sharp decrease in the energy performance of mixed-flow pumps within the over-load flow rate range, broadening its efficient operation range. (2) The decrease in the axial velocity under the effect of AIGV explains the primary fluid physics of the increased efficiency. (3) The improvement in the match between the impeller inflow angle distribution and the impeller blades structure suppresses the generation and transmission of the flow separation on the pressure side, and reduce the near-wall energy dissipation. The novel HA-AIGV obtains a better flow control effect.

Computational fluid dynamics of free convection and radiation on thermal performance of light emitting diode applications with trapezoidal-finned heat sink

The reduction in energy consumption through the energy performance improvement in the use of artificial lighting system found in all sectors of the economy is one of the very important strategies of achieving sustainable energy development. In contrast to conventional lighting, light-emitting diodes (LEDs) provide better energy efficiency. To effectively optimize the performance and efficiency of the LED lighting, the LED heat needs to be dissipated adequately. In the present work, the cooling performance of a radial heat sink with trapezoidal fins is numerically investigated under the consideration of natural convection and radiation. The study investigated the influence of the number of fins (20≤Nf≤36), the height of the fins (15mm≤hfH≤35mm) and the applied heat flux (300W/m2≤q˙≤1100W/m2) on the thermal resistance (Rth) and heat transfer coefficient (havg) of the heat sink. The numerical results obtained from this work were validated with literature, and an excellent agreement was established. The results found that both the Rth and the havg of the heat sink decreased as the number of fins (Nf) and fin height (hfH) increased. Meanwhile, the number of fins (Nf) has an optimal value for achieving the heat sink's effective cooling performance.

Blade redesign based on inverse design method for energy performance improvement and hydro-induced vibration suppression of a multi-stage centrifugal pump

As the urgency of the global energy crisis escalates and environmental protection standards become more stringent, the industrial sector is placing increased emphasis on enhancing energy efficiency and advancing vibration control technologies. Within this context, multi-stage centrifugal pumps (MSCPs), pivotal in energy systems, play a crucial role in influencing both system performance and environmental impact. This paper embarked on employing an inverse design method (IDM) to innovate the redesign of MSCP blades, introducing a steady-state index for characterizing the intensity of unsteady pressure fluctuations, thereby streamlining optimization costs. Optimization techniques utilizing an artificial neural network model and a multi-objective evolutionary algorithm were employed to achieve an optimal balance between maximizing energy efficiency and reducing hydro-induced vibrations. The optimized MSCP enhanced not only boosting performance but also a 2.75 % increase in weighted efficiency, significantly widening the high-efficiency operation zone. The improvement in vibration characteristics was manifested by an average reduction of more than 25 % in the amplitude of the primary frequency of pressure pulsations within the double volute, with a maximum reduction reaching 50.9 %. Furthermore, the research delved into the analysis of the internal energy dissipation mechanisms of MSCPs, drawing upon the entropy production theory and the enstrophy concept. This analysis reveals that energy dissipation in the mainstream zones is predominantly affected by shear enstrophy, whereas, in the wall regions, it is primarily governed by fluid velocity. The comprehensive performance enhancement of the optimized model is significantly credited to the refinement of the blade profile.

Energy and exergy performance improvement of coupled PV–TEG module by using different shaped nano-enhanced cooling channels

In this study, impacts of using different cooling channels (L, T and U-shaped) on the energy and exergy performances of combined PV/TEG (photovoltaic/thermoelectric generator) unit are numerically assessed by using FEM based three dimensional high fidelity computational simulations. Cooling performance is boosted by using ternary nanofluid in the channels. The study is conducted for a range of Reynolds numbers (Re, between 50 and 500), nanofluid cooling inlet temperatures (between 15 °C and 23 °C), and nanoparticle loading amounts (between 0 and 3%). Evaluations are done on average PV-cell temperature, PV/TEG output powers, exergy efficiency, improve potential (IP), and sustainability index (SI). U-shaped and T-shaped channels are found to offer the greatest and worst cooling performances among various cooling channels. When comparing the lowest and maximum Re cases, the average temperature drops for PV cells are 3.54 °C for T channel and 2.55 °C for U channel. Exergy efficiency is determined to be 14.2% with T-channel at Re=50 and 14.6% with U-channel at Re=500. Taking into consideration different channels, an increase in the inlet temperature from 15 °C to 23 °C leads to an average rise in cell temperature of 6 °C. The IP rises with coolant inlet temperature while using T-channel. SI values fall as input temperature increases, although values between 1.164 and 1.175 may be achieved by using different cooling channels. Using nanofluid with higher loading results in higher exergy efficiency when comparing exergetic performances, with U-channel design exhibiting the highest performance. For the range of parameters considered, the coolant inlet temperature at the channel entry has the highest effect on PV cell temperature reduction; 8.5 °C of temperature reduction is feasible. By employing U-channel cooling, the maximum value of Re, the highest loading of nanoparticles, and the lowest inlet temperature yield the best exergy efficiency. The best and worst situations’ respective exergy efficiencies are determined to be 15% and 14.1%. Utilizing T-channel cooling with water at a flow flow rate and a higher input temperature is the scenario with the biggest potential for exergy improvement; the value is 2.9. When different operational parameters are varied, the SI falls between 1.176 to 1.16.

Performance evaluation and comparative study on a novel solar-heat-driven ejection-compression hybrid cooling system with subcooling storage

Refrigeration technology contributes to 10∼15% of global energy consumption, resulting in significant carbon emission. Solar-driven ejection-compression refrigeration system is promising for reducing electricity consumption and carbon emissions. However, existing solar ejection-compression refrigeration systems suffer from drawbacks of low heat utilization efficiency, oversized solar collectors, and thermal leakage due to large temperature differences of storage devices. Addressing these challenges, this study proposes and investigates a new solar-assisted ejector-compressor hybrid refrigeration system with subcooling storage coupled at intermediate temperatures. The system model is established, and the ejector model is experimentally validated. Through system modelling, an energetic and exergetic performance comparative analyses are conducted. The results indicate that the COP of the proposed system is 9.7% higher than that of traditional system combinations, producing the same cooling capacity with the same generating heat. Moreover, considering the stored cooling energy can be fully converted to cooling energy at evaporating temperatures, the COPh of the new system reaches 8.29, 24.5% higher than traditional systems. The cooling storage at 15°C with 0.325 ejector entrainment ratio suggests a reduction of approximately two-thirds in energy storage, lower temperature differences, and reduced thermal leakage, leading to decreased space and economic costs and improved energy performance. Additionally, as the COPh, COPgh, and ηex of MCS mode consistently outperform those of ZCS and HCS modes, the MCS mode is prioritized in system operation. This study underscores that the new system offers superior overall energy efficiency and requires smaller storage devices compared to traditional systems, revealing its promising practical applications.

MULTI-OBJECTIVE OPTIMIZATION STUDY OF RESIDENTIAL ENERGY CONSUMPTION BASED ON EDH AND THE STOCHASTIC OPERATION OF AIR CONDITIONING

ABSTRACT Current requirements for residential energy-efficient design solutions in China are relatively homogeneous, requiring only improvements in overall building energy performance, often ignoring the energy differences between different residential housing units. This paper proposes a multi-objective research framework based on an occupant behavior model of air conditioning and a Non-dominated Sorting Genetic Algorithm-II (NSGA-II) to study energy-efficient design solutions for residential envelopes. The optimal energy-saving design scheme has a 22.56% and 35.34% reduction in energy consumption difference between residential units and overall building energy consumption, respectively, both of which have been optimized substantially. Moreover, the overall energy performance of the building can be improved when the “energy performance difference between housing units” (EDH) is reduced, which verifies that EDH is an important criterion for improving the energy performance of residential housing units.

3D Numerical Modeling to Assess the Energy Performance of Solid–Solid Phase Change Materials in Glazing Systems

This research investigates the energy efficiency of a novel double-glazing system incorporating solid–solid phase change materials (SSPCMs), which offer significant advantages over traditional liquid–solid phase change materials. The primary objective of this study is to develop a 3D numerical model using the finite volume method, which will be followed by a parametric study under real climatic boundary conditions. A proposed double-glazing setup featuring a 2 mm layer of SSPCM applied on the inner glass pane within the air gap is modeled and analyzed. The simulations consider various transient temperatures and ranges of the SSPCM to evaluate the energy performance of the system under different weather conditions of Miami, FL during the coldest and hottest days of the year, both in sunny and cloudy conditions. The results demonstrate a notable improvement in energy performance compared to standard double-glazing windows (DGWs), with the most efficient SSPCM configuration exhibiting a phase transition temperature and range of 25 °C and 1 °C, respectively. This configuration achieved energy savings of 24%, 26%, and 23% during summer sunny, winter sunny, and winter cloudy days, respectively, relative to DGWs during cooling and heating degree hours. However, a 3% energy loss was observed during summer cloudy days. Overall, the findings of this study have shown the potential for energy savings by incorporating SSPCM with suitable thermophysical properties into double-glazing systems.

Solar salt encapsulated into 3D printed activated carbon/alumina supports for thermal energy storage applications

The encapsulation of phase change materials (PCMs) into additive manufactured porous supports is attracting great interest for developing thermal energy storage (TES) materials with improved energy performance. Here, highly porous (86 %) self-supported 3D activated carbon/alumina supports are fabricated by direct ink writing (DIW) and, then, infiltrated with solar salt, a highly corrosive PCM with a melting temperature around 220 °C commonly employed in concentrated solar power plants. This novel, robust, chemically compatible, and lightweight infiltrated 3DTES exhibits good thermal energy storage efficiency (70 %) and thermal stability, high energy storage density (381 J g−1), and avoids the liquid leakage of the molten salt. Besides, the 3D activated carbon/alumina support promotes a better ability to absorb solar energy (79 %) and enhances the thermal conductivity of the solar salt (up to 64 %). These results validate the use of DIW for manufacturing innovative TES with an enhanced energy storage behaviour.