Search Results (362)

This study empirically evaluates the energy and carbon reduction effects of an envelope retrofit applied to an aging public building in South Korea. Unlike previous studies that primarily relied on simulation-based analyses, this work fills the empirical research gap by using actual utility billing data collected over one pre-retrofit year (2019) and two post-retrofit years (2023–2024). The retrofit included improvements to exterior walls, roofs, and windows, aiming to enhance thermal insulation and airtightness. The analysis revealed that monthly electricity consumption was reduced by 14.7% in 2023 and 8.0% in 2024 compared to that in the baseline year, with corresponding decreases in electricity costs and carbon dioxide emissions. Seasonal variations were evident: energy savings were significant in the winter due to reduced heating demand, while cooling energy use slightly increased in the summer, likely due to diminished solar heat gains resulting from improved insulation. By addressing both heating and cooling impacts, this study offers practical insights into the trade-offs of envelope retrofitting. The findings contribute to the body of knowledge by demonstrating the real-world performance of retrofit technologies and providing data-driven evidence that can inform policies and strategies for improving energy efficiency in public buildings. Full article

Over recent decades, phase-change materials (PCMs) have gained prominence as latent-heat thermal energy storage systems in building envelopes because of their high energy density. However, only PCMs that complete a full daily charge–discharge cycle can deliver meaningful energy and carbon-emission savings. This simulation study introduces a methodology that simultaneously optimizes PCM integration for storage efficiency, indoor thermal comfort, and energy savings. Two new indicators are proposed: overall storage efficiency (EC_n), which consolidates heating and cooling-efficiency ratios into a single value, and the performance factor (PF), which quantifies the PCM’s effectiveness in maintaining thermal comfort. Using EnergyPlus v8.9 coupled with DesignBuilder, a residential ASHRAE 90.1 mid-rise apartment was modeled in six warm-temperate (Cfb) European cities for the summer period from June 1 to August 31. Four paraffin PCMs (RT-22/25/28/31 HC, 20 mm thickness) were tested under natural and controlled ventilation strategies, with windows opening 50% when outdoor air was at least 2 °C cooler than indoors. Simulation outputs were validated against experimental cubicle data, yielding a mean absolute indoor temperature error ≤ 4.5%, well within the ±5% tolerance commonly accepted for building thermal simulations. The optimum configuration—RT-25 HC with temperature-controlled ventilation—achieved PF = 1.0 (100% comfort compliance) in all six cities and delivered summer cooling-energy savings of up to 3376 kWh in Paris, the highest among the locations studied. Carbon-emission reductions reached 2254 kg CO₂-e year⁻¹, and static payback periods remained below the assumed 50-year building life at a per kg PCM cost of USD 1. The EC_n–PF framework, therefore, provides a transparent basis for selecting cost-effective, energy-efficient, and low-carbon PCM solutions in warm-temperate buildings. Full article

Urban areas are responsible for most of Europe’s energy demand and emissions and urgently require building retrofits to meet climate neutrality goals. This study evaluates the energy efficiency potential of three public school buildings in western Macedonia, Greece—a cold-climate region with high heating needs. The buildings, constructed between 1986 and 2003, exhibited poor insulation, outdated electromechanical systems, and inefficient lighting, resulting in high oil consumption and low energy ratings. A robust methodology is applied, combining detailed on-site energy audits, thermophysical diagnostics based on U-value calculations, and a techno-economic assessment utilizing Net Present Value (NPV), Internal Rate of Return (IRR), and SWOT analysis. The study evaluates a series of retrofit measures, including ceiling insulation, high-efficiency lighting replacements, and boiler modernization, against both technical performance criteria and financial viability. Results indicate that ceiling insulation and lighting system upgrades yield positive economic returns, while wall and floor insulation measures remain financially unattractive without external subsidies. The findings are further validated through sensitivity analysis and policy scenario modeling, revealing how targeted investments, especially when supported by public funding schemes, can maximize energy savings and emissions reductions. The study concludes that selective implementation of cost-effective measures, supported by public grants, can achieve energy targets, improve indoor environments, and serve as a replicable model of targeted retrofits across the region, though reliance on external funding and high upfront costs pose challenges. Full article

Heating, ventilation, and air-conditioning (HVAC) systems account for the largest share of energy consumption in European Union (EU) buildings, representing approximately 40% of the final energy use and contributing significantly to carbon emissions. Latent thermal energy storage (LTES) using phase change materials (PCMs) has emerged as a promising strategy to enhance HVAC efficiency. This review systematically examines the role of latent thermal energy storage using phase change materials (PCMs) in optimizing HVAC performance to align with EU climate targets, including the Energy Performance of Buildings Directive (EPBD) and the Energy Efficiency Directive (EED). By analyzing advancements in PCM-enhanced HVAC systems across residential and commercial sectors, this study identifies critical pathways for reducing energy demand, enhancing grid flexibility, and accelerating the transition to nearly zero-energy buildings (NZEBs). The review categorizes PCM technologies into organic, inorganic, and eutectic systems, evaluating their integration into thermal storage tanks, airside free cooling units, heat pumps, and building envelopes. Empirical data from case studies demonstrate consistent energy savings of 10–30% and peak load reductions of 20–50%, with Mediterranean climates achieving superior cooling load management through paraffin-based PCMs (melting range: 18–28 °C) compared to continental regions. Policy-driven initiatives, such as Germany’s renewable integration mandates for public buildings, are shown to amplify PCM adoption rates by 40% compared to regions lacking regulatory incentives. Despite these benefits, barriers persist, including fragmented EU standards, life cycle cost uncertainties, and insufficient training. This work bridges critical gaps between PCM research and EU policy implementation, offering a roadmap for scalable deployment. By contextualizing technical improvement within regulatory and economic landscapes, the review provides strategic recommendations to achieve the EU’s 2030 emissions reduction targets and 2050 climate neutrality goals. Full article

The construction industry is one of the main areas of energy consumption and carbon emissions, and strengthening research on the thermal performance of building facades can effectively promote energy conservation and emission reduction. Compared with traditional static enclosure structures, dynamic skin can adapt its functions, characteristics, and methods based on constantly changing environmental conditions and performance requirements. It has great potential in adapting to the environment, reducing energy consumption, adjusting shading and natural ventilation, and improving human thermal and visual comfort. To comprehensively understand the key technologies of dynamic skin energy-saving design, previous research results were comprehensively compiled from relevant databases. The research results indicate that various types of dynamic skins, intelligent materials, multi-layer facades, dynamic shading, and biomimetic facades are commonly used core technologies for dynamic facades. Parametric modeling, computer simulation, and multi-objective algorithms are commonly used to optimize the performance of dynamic skin. In addition, integrated technology design, interaction design, and lifecycle design should be effective methods for improving dynamic skin energy efficiency, resident satisfaction, and economic benefits. Despite current challenges, dynamic skin energy-saving technology remains one of the most effective solutions for future sustainable building design. Full article

In the housing sector emission reduction builds on a shift from fossil fuels to renewable energy sources and increasing the efficiency of energy usage, with heating playing a dominant role in comparison to that of electricity. For electricity production in the residential sector, research shows that different settings of (co-)ownership in renewables are linked to a greater tendency to invest in energy-efficient devices or to adopt more energy-conscious behaviours. The empirical analysis demonstrates that fully-fledged prosumers, i.e., consumers who have the option to choose between self-consumption and selling to third parties or the grid, exhibit a higher tendency to invest in energy efficiency and that only this group manifests a greater likelihood of engaging in conscious-energy consumption behaviour. This paper extends the analysis to include heating in the residential sector. The study conducted an ANCOVA based on a sample of 2585 German households. The findings show that, depending on the (co-)ownership setting, the willingness to invest and to adopt energy-efficient practices grows considerably. Consumer-sellers demonstrate the highest willingness to invest and adapt energy conscious behaviour. Furthermore, regarding heating in particular, self-consumers are also inclined to invest and engage in energy-savings behaviour. Full article

Applying circular economy principles to the renovation of existing buildings is increasingly recognized as essential to achieving Europe’s climate and energy goals. However, current decision-making frameworks rarely integrate life cycle carbon assessment with multi-criteria evaluation to support circular renovation strategies. This paper introduces an innovative framework that combines life cycle carbon assessment with multi-criteria decision analysis to identify and sequence circular renovation measures. The framework was applied to a residential case study in the Netherlands, using IES VE for operational carbon assessment and One Click LCA for embodied carbon assessment, with results evaluated using PROMETHEE multi-criteria analysis. Renovation measures were assessed based on operational and embodied carbon (including Module D), energy use intensity, cost, payback period, and disruption. The evaluation also introduced the embodied-to-operational carbon ratio (EOCR), a novel metric representing the proportion of embodied carbon, including Module D, relative to operational carbon savings over the building’s lifecycle. The homeowner’s preferences regarding these criteria were considered in determining the final ranking. The findings show that circular insulation options involving reused materials and designed for disassembly achieved the lowest embodied carbon emissions and lowest EOCR scores, with reused PIR achieving a 94% reduction compared to new PIR boards. The impact of including Module D on the ranking of renovation options varies based on the end-of-life scenario. The framework demonstrates how circular renovation benefits can be made more visible to decision-makers, promoting broader adoption. Full article

The building sector is responsible for significant carbon emissions and energy consumption, making it a critical field for global energy-saving and emission reduction efforts to combat climate change. This study calculated the building carbon emissions (BCE) of 30 provinces in the Chinese Mainland from 2010 to 2020 using the IPCC carbon emission factor method based on the statistical data of energy consumption and building materials, and then the decoupling relationship between BCE and the construction land area (CLA) was analyzed. The results are as follows: (1) BCE exhibited an overall increase from 2010 to 2020, yet at a descending rate, with a prominent decrease in indirect BCE (IBCE); (2) BCE and direct BCE (DBCE) were higher in the north but lower in the south, while IBCE was higher along the eastern coast; (3) the provinces in North China and Northeast China possess the largest areas of construction land, but the growth of CLA was the slowest or even declined in the later stage of the study; (4) the decoupling relationship between BCE and CLA is dominated by expansive negative decoupling or strong negative decoupling. The growth of BCE is generally much faster than the expansion of construction land. The findings will have important reference for achieving energy-saving and “dual carbon” strategic development goals in China. Full article

The electric power industry is not only facing the pressure from the reduction of industrial and commercial electricity prices to stimulate the significant growth of demand, but also facing the increasingly serious pressure of unreasonable consumption caused by cross-subsidies; the cross-subsidy mitigation effect and energy-saving effect of the current tiered electricity price policy have basically disappeared. This article examines the main variables that affect the electricity demand and carbon emissions in order to develop a better tiered electricity pricing scheme that can effectively manage cross-subsidies in electricity prices while simultaneously saving energy and lowering carbon emissions. The China Statistical Yearbook’s electricity balance sheets for 2013–2020 are used in this article, along with pertinent data from the State Grid Corporation of China and the China Statistical Yearbook for 2006–2016. It builds an electricity demand model for classified users by using the time series analysis method and multiple statistical regression method. The variables are then subjected to a Granger causality test and a cointegration test in this article. The analysis shows that the adjustment of the electricity price policy has a significant impact on energy-saving and carbon reduction, and for residential electricity consumption, the income variable is the main factor affecting the electricity demand. We take residents’ affordability as the constraint condition for dividing the range of electricity and determining the beneficiary group, take the carbon emission responsibility target and the cross-subsidy degree alleviation target as constraints in determining the tiered price difference, propose an improvement scheme for the tiered electricity price, and carry out the sensitivity analysis of the influence between the parameters. The results show that the optimization improves the precision of the cross-subsidy treatment and significantly improves the effects of energy conservation and emission reduction. Full article

The global environment has been facing sustainability threats recently owing to industrial and economic expansion. Hence, achieving the goals of carbon peak and carbon neutrality is crucial for promoting sustainable economic growth. To help the transportation industry achieve these goals, this study selects eight variables, including population size, per capita GDP, personal vehicle ownership, passenger and freight turnover, and green space coverage, as factors influencing the carbon emissions of the transportation industry in Jiangsu Province. This research uses these variables as the basis for predicting and analyzing transportation carbon emission trends from 2000 to 2021. In addition, the current study forecasts the future carbon emissions of the transportation industry and estimates the time of carbon emission peak in Jiangsu Province. To verify the accuracy of the results, this study compares the predicted results with those from other models. The whale optimization algorithm–support vector machine model is found to have the fewest errors among several models. On this basis, targeted measures are proposed to accelerate the carbon peak process and ensure the smooth achievement of carbon neutrality goals in Jiangsu Province. Results indicate that under the current policy measures, peak carbon emissions in Jiangsu Province will occur in 2038, with a peak of 48.72 million tons. Jiangsu Province should actively adopt energy-saving and emission-reduction measures, build a green and low-carbon transportation development model, and achieve the carbon peak target ahead of schedule. Findings from this study will provide valuable insights and practical recommendations for policy makers and stakeholders to formulate effective strategies for carbon reduction in the transportation sector, contributing to the sustainable development of China and the world. Full article

The construction industry is a major contributor to global CO₂ emissions due to high energy consumption in buildings and the production of carbon-intensive materials. Although Big Data is recognized as a transformative tool for improving sustainability by optimizing energy use, resource efficiency, and decision-making, its adoption in construction remains limited. This study aims to identify and analyze the technical, economic, and organizational factors influencing Big Data adoption for sustainability and climate neutrality in Swedish construction companies. A quantitative survey was conducted among 150 industry professionals, and the data were analyzed using descriptive statistics, Spearman correlations, ANOVA, chi-squared (χ²) tests, and principal component analysis (PCA), guided by the diffusion of innovations (DOI) theory. The results indicate that the respondents broadly acknowledge benefits such as energy savings, cost reductions, and improved decision support. The PCA revealed two key dimensions—one capturing technical/environmental benefits, the other economic/regulatory benefits—while barriers included standardization issues, limited digital skills, and investment uncertainties persist. The findings suggest that overcoming these barriers is essential for accelerating a strategic and climate-aligned digital transition in construction, offering actionable insights for policymakers and industry leaders. Full article

Energy efficiency has emerged as a crucial focal point in global agendas, being recognized for its pivotal role in combatting climate change, bolstering energy security, and fostering economic growth. Governments worldwide are formulating ambitious targets and enacting comprehensive strategies to optimize energy utilization across various sectors. This involves the formulation of policies, provision of incentives, and facilitation of collaborations to encourage energy-efficient practices, ultimately steering towards a sustainable and energy-efficient future. Notably, the residential sector stands as a pivotal component in these efforts due to its substantial share of energy consumption. This paper evaluates the strategic vision of Morocco concerning energy efficiency within the residential sector from its inception to the projected initiatives up to 2030. The analysis focuses on the current iteration of thermal regulations and its implications. Although specific numerical outcomes are not discussed herein, the implementation of these regulations is observed to yield notable benefits, including reductions in energy bills and gains in annual primary energy. These advantages are estimated to result in a substantial decrease in final energy consumption, equating to significant savings for end-users. Additionally, to cover the expenses associated with building repairs and thermal enhancements, an extra fee is levied, varying based on building typology and climatic region. Despite this additional investment, the associated costs typically exhibit a favorable payback period, on average, underscoring the efficacy of regulatory and profitability measures in driving energy efficiency within the residential sector. This paper examines Morocco’s strategic approach to energy efficiency in the residential sector, focusing on its thermal building regulation RTCM (Moroccan thermal regulation on construction). Energy efficiency is recognized as essential for reducing GHG (greenhouse gas) emissions, enhancing energy security, and lowering costs. Using simulation models across six climatic zones and three residential building types, the study highlights RTCM’s significant impact—achieving national energy savings between 39% and 68%. Despite added costs for thermal improvements, the measures show favorable payback periods, confirming RTCM’s strong energy and economic performance and its potential role in shaping future policies. Full article

With the increasing demand for energy-efficient and sustainable building materials, innovative cooling technologies have become a key focus in the construction industry. This study developed a double-layer cooling coating integrating evaporation and radiation mechanisms. The first layer consists of a TiO₂/PUA radiation layer, where rutile TiO₂ is incorporated into polyurethane acrylate (PUA) resin to enhance solar reflectivity. The second layer is a P(NVP-co-NMA) hydrogel, which evaporates water at high temperatures and absorbs moisture from the air at low temperatures, eliminating the need for additional water supply systems. The TiO₂/PUA@P(NVP-co-NMA) coating demonstrates high solar reflectivity and infrared emissivity, effectively reducing indoor temperatures by dissipating heat through water evaporation and radiative cooling. Testing showed a temperature reduction of approximately 7.6 °C in a small house with this coating under simulated conditions. This material demonstrates favorable properties that may make it suitable for applications on building roofs and exterior walls, potentially addressing some limitations of conventional evaporative or radiative cooling systems. Its observed multi-effect cooling performance indicates promise for contributing to energy savings in sustainable building designs. Full article

Energy transition is a challenge for remote northern communities mainly relying on diesel for electricity generation and space heating. Solar-assisted ground-coupled heat pump (SAGCHP) systems represent an alternative that was investigated in this study for the Kuujjuaq Forum, a multi-activity facility in Nunavik, Canada. The energy requirements of community buildings facing a subarctic climate are poorly known. Based on energy bills, technical documents, and site visits, this study provided an opportunity to better document the energy consumption of such building, especially considering the recent solar photovoltaic (PV) system installed on part of the roof. A comprehensive model was developed to analyze the building’s heating demand and simulate the performance of a ground-source heat pump (GSHP) coupled with PV panels. The air preheating load, accounting for 268,200 kWh and 47% of the total heating demand, was identified as an interesting and realistic load that could be met by SAGCHP. The GSHP system would require a total length of at least 8000 m, with boreholes at depths between 170 and 200 m to meet this demand. Additional PV panels covering the entire roof could supply 30% of the heat pump’s annual energy demand on average, with seasonal variations from 22% in winter to 53% in spring. Economic and environmental analysis suggest potential annual savings of CAD 164,960 and 176.7 tCO₂eq emissions reduction, including benefits from exporting solar energy surplus to the local grid. This study provides valuable insights on non-residential building energy consumption in subarctic conditions and demonstrates the technical viability of SAGCHP systems for large-scale applications in remote communities. Full article

Passive buildings are increasing in popularity in Canada. This paper examines two passive buildings initially constructed in the past decade: the Peterborough passive multi-unit residential building (MURB) and the Wolfe Island single-family dwelling. A post-occupancy evaluation was performed on the buildings. The buildings were modelled in HOT2000 and the Passive House Planning Package (PHPP) to ensure the validity of the results. The energy bills were collected from the building owners to acquire the real-time consumption of the buildings. The models have shown a good agreement with the collected data. Furthermore, data loggers were installed in both buildings for indoor temperature monitoring to ensure that they adhere to the passive house explicit criteria. Internal gains, shading, and orientation were analyzed to assess their effect on heating and cooling loads. Peterborough MURB has shown more energy-saving potential compared to the Wolfe Island passive house. Heating load reduction has been compared, more than five times, to the cooling load reduction potential. The reduction in GHG emissions can be up to 39% when passive house parameters are applied to the Wolfe Island house. This paper has shown the potential of the passive house in relation to sustainable buildings in Northern climates. Full article