Search Results (508)

Existing industrial buildings represent a critical but under-addressed field for operational carbon emission reduction, as retrofit decisions are constrained by production continuity, limited investment capacity, and heterogeneous technical options. This study developed a decision support framework integrating the Decision-Making Trial and Evaluation Laboratory (DEMATEL) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) methods to evaluate and prioritize operational phase decarbonization retrofit schemes for existing industrial buildings. The framework was applied to the Thyssenkrupp S Plant in eastern China, where ten candidate schemes were identified through an energy audit, on-site investigation, and expert consultation. The results show that heating, ventilation, and air conditioning (HVAC) operational control and temperature set-point optimization ranked first, followed by lighting operational management and automatic control. These management-based measures offer strong near-term applicability because of their low investment, short payback periods, limited implementation disturbance, and immediate emission reduction benefits. Their sustained effectiveness, however, requires standardized procedures, staff education, energy monitoring, and appropriate automation. Rooftop photovoltaics provide the largest annual carbon reduction but have a lower short-term priority because of their high upfront investment. Expert-consistency testing and sensitivity analyses, including criterion weight perturbation, preference scenarios, and Monte Carlo simulation, support the robustness of the leading ranking pattern. The findings support staged retrofit planning that prioritizes durable management measures in the short term, equipment-level efficiency improvements in the medium term, and renewable energy deployment in the long term. Full article

Vernacular heritage conservation often separates material fabric, environmental adaptation, and social meaning. This study addresses that separation for one settlement. Socio-environmental heritage is defined here as heritage whose significance resides in the documented interdependence of environmental conditions, material practice, social organisation, and customary governance, rather than in fabric or imagery alone. The single purpose of the article is to develop and demonstrate an evidence-based method for interpreting and conserving Thee Ain Heritage Village in Al-Baha, Saudi Arabia, as such a system. A qualitative architectural case-study design combines a structured literature search, regional comparison, the author’s 2014 field observations and photographs, and published digital-heritage, energy-retrofit, and conservation studies; no human-participant data are analysed. Evidence is organised through three analytical layers—climatic material, socio-spatial, and customary governance—and each evidence–interpretation proposition is classified as directly observed, supported architectural inference, or hypothesis requiring measurement; conservation translation is treated as the output of this sequence rather than as a parallel analytical layer. Coded claim units are documented individually so that every interpretation and implication can be traced to its source, strength, and limitation. The analysis links rocky siting, stone and timber assemblies, thick load-bearing madameek walls, limited openings, vertical domestic hierarchy, controlled thresholds, and the agricultural setting to conservation priorities at landscape, construction, spatial, and adaptation scales. These priorities include compatible repair, retention of wall depth and opening logic, protection of privacy gradients and threshold sequences, and service integration without reducing the village to stone-clad imagery. Unlike previous work centred on digital documentation, energy modelling, or policy-level preservation, the contribution is an evidence-structured method linking architectural observation to bounded interpretation, conservation decisions, and explicit future testing requirements. Full article

Dynamic energy tariffs increasingly mirror renewable generation and market conditions, yet most techno-economic assessments of residential retrofit and flexibility measures still rely on simplified, static tariffs, risking-biassed cost estimates. This study systematically maps energy tariff structures across three classification tables, showing that dynamic and weather-responsive tariffs are underrepresented in ex-ante building energy modelling. Building on this gap, four ex-ante tariff-modelling methods are developed and validated, namely a fixed tariff, a time-of-use (ToU) tariff, a weather-dependent real-time-pricing (RTP) mechanism grounded in a residual-load proxy, and a capacity-based network tariff, illustrated for the Flemish context. The RTP mechanism is calibrated against two years of Belgian day-ahead prices (ENTSO-E) and Elia demand, as well as PV- and wind-generation data, reaching a monthly correlation of ρ = 0.78 (hourly ρ = 0.43, excluding 2022) and ρ = 0.71 for the final quantile-mapped tariffs, using only weather data (.epw) and three calibratable parameters. An illustrative building-level application shows that, for an identical unoptimised demand profile, a weather-driven RTP tariff changes the projected annual electricity cost by roughly 33–44%, against only 1–3% for a static ToU tariff, confirming that tariff structure must be an explicit ex-ante modelling choice. Full article

Reliable drinking-water production is difficult on remote islands where brackish-water delivery is intermittent, technical personnel are scarce, and reverse-osmosis plants are manually operated. This study presents an operational characterization of an Internet of Things (IoT) retrofit deployed in Santa Cruz, Galápagos; it is not a controlled before-and-after effectiveness evaluation. An ESP32-based M5Stack Tough controller, distributed ESP-NOW sensing nodes, relay–contactor interfaces, a binary pressure permissive, and a ThingSpeak cloud layer were integrated without replacing the existing pumps and membranes. The exported primary-flow channel contained 4,603,989 numeric observations, including 500 pre-official test readings. Operational analyses used 4,603,489 numeric observations from the official monitoring period; 4,603,340 values remained after nominal-range filtering, and positive flow had a median of 12 L/min (interquartile range: 11–15 L/min). Among 332 logged high-pressure commands, 326 were preceded by a low-pressure command (98.2% unbounded command-state consistency), whereas 275 occurred within a 120 s analytical bound (82.8%). The median low-to-high command delay was 27 s (interquartile range: 11–70 s). Four organizational representatives completed a published 41-item Industry 4.0 maturity instrument before and after deployment; the self-reported overall mean was 0.26 at baseline and 1.95 post-deployment, and these results are interpreted descriptively. Energy-consumption and production data were confidential and unavailable to the authors, while water-quality variables were not measured. The contribution is therefore a long-duration, local-first legacy retrofit with auditable telemetry and explicit limitations, rather than a claim of optimized desalination performance. Full article

In response to issues such as disordered airflow distribution and prominent local hotspots in campus non-standard data centers, this study took a non-standard raised-floor air-supply data center at a university in Hangzhou as the research object, and used a combination of on-site measurements and computational fluid dynamics (CFD) numerical simulation to investigate the optimization of the thermal environment. The temperature and air velocity of the data center were measured using a handheld hot-wire anemometer, and a standard k-ε turbulence model was established on the 6SigmaDC platform (now Cadence Reality DC Design Pro, version 2024.1). Model accuracy was confirmed through grid independence verification with three mesh levels and statistical error metrics (MAE, MBE, RMSE) across multiple measurement zones. The results show that the mean absolute error of temperature does not exceed 0.9 °C in all zones and the mean absolute error of air velocity does not exceed 0.20 m/s, indicating that the model effectively reproduces the airflow distribution and thermal environment of the data center. On this basis, to address the uneven airflow distribution in the underfloor plenum, an optimization strategy was proposed that involved the installation of composite baffles and the coordinated adjustment of variable floor tile openings. Eight representative simulation scenarios were designed, with the coefficient of variation and air supply uniformity index as evaluation indicators. Results indicate that the combined effect of perforated baffles and variable floor tile openings is the optimal strategy, reducing the range of net airflow among air supply outlets from 0.100 to 0.077 m³/s, decreasing the coefficient of variation from 12.8% to 10.8%, and increasing the air supply uniformity index by 10.7%. Whole-room thermal environment verification shows that the optimal scheme reduces the supply heat index (SHI) from 0.42 to 0.35, with an estimated PUE reduction of about 0.03, achieving both airflow uniformity improvement and energy-saving benefits. By improving the cooling efficiency and reducing the PUE, this retrofit strategy contributes to the sustainable operation of small-to-medium-sized campus data centers, supporting energy efficiency and carbon footprint reduction goals under green campus and low-carbon initiatives. Full article

This paper examines the results of in-situ U-value measurements across 36 traditional uninsulated solid walls and early mass concrete construction in Ireland. As the retrofit of poorly performing buildings becomes increasingly important, establishing an accurate thermal performance baseline for common solid wall types is essential. Existing assumptions in Ireland are based on default U-values used for Energy Performance Certificates or on calculated values derived using BR443 or ISO 6946 with reference thermal conductivities, while no large-scale dataset of in-situ U-values for Irish solid wall construction currently exists. This paper introduces a new dataset for such walls and compares it to the associated default and calculated U-values. Brick walls < 325 mm performed on average 36.8% better than default assumptions, while brick walls ≥ 325 mm aligned on average reasonably well with the defaults. However, the results ranged from −18.7 to +33.1% of the defaults. Stone walls performed on average 7.2% better than the defaults but with substantial variability at −54.8 to +40.8%. In contrast, mass concrete walls performed significantly worse than assumed (+37.2%), while an earthen wall exceeded expectations by 21.5%. The findings demonstrate that in-situ U-value measurements provide a valuable, non-invasive means of improving the accuracy of thermal performance assessments for traditional solid walls. Full article

To address the renewable energy hosting capacity problem in regional power grids under security, stability, and power supply adequacy constraints, this paper proposes an energy storage configuration method that coordinates demand–response, synchronous condensers, grid-forming renewable energy retrofits, and storage. First, wind and photovoltaic output scenarios are generated by clustering historical data while considering wind–solar correlations, and a time-of-use-price-based demand–response model is established to improve the net-load profile. Second, a three-layer optimization framework is constructed. The upper layer determines the rated power and energy capacity of the storage system and minimizes storage investment and operation and maintenance costs. The middle layer performs source–grid–load–storage coordinated dispatch under the storage boundary provided by the upper layer and minimizes the total operating costs while embedding node voltage and short-circuit ratio security checks. The lower layer maximizes renewable energy hosting capacity through incremental capacity iteration and determines the maximum admissible renewable capacity subject to reliability, security, and stability constraints. A normalized normal constraint (NNC) method is adopted to solve the multi-objective three-layer model. Case studies based on an improved IEEE 118-bus system show that the coordinated measures can significantly increase hosting capacity, reduce storage demand, and improve voltage and frequency security. Full article

Simulation-dependent energy analysis has long dominated building retrofit research, yet this paradigm presents substantial barriers for non-expert building owners who lack technical software proficiency and detailed building documentation-a challenge compounded by the “curse of dimensionality” when multivariate analysis requires thousands of samples beyond available empirical records. Leveraging retrofit data accumulated through Korea’s Green Remodeling programs since 2017, this study proposes a Copula-Genetic Algorithm (Copula-GA) integrated framework that enables rational retrofit decision-making with minimal user inputs (construction year, floor area, structural type). From 178 documented retrofit cases, Gaussian copula-based multivariate sampling generated 10,000 synthetic records while preserving inter-variable dependency structures. Building physics constraints addressing vintage-thermal performance and capacity-efficiency relationships filtered implausible combinations, yielding 9898 valid cases with correlation matrix fidelity confirmed by a Frobenius norm deviation of 0.043. Evolutionary clustering employing a composite fitness function of Silhouette coefficient (0.68) and Davies-Bouldin Index (0.52) identified K = 16 as the optimal partition, categorizing outcomes into four reference model archetypes: Lightweight Structure (Type A, 27.0% reduction, 15.7-year payback), Masonry Structure (Type B, 29.0%, 14.8 years), RC Structure (Type C, 30.7%, 13.4 years), and Mixed Structure (Type D, 30.9%, 13.1 years). The proposed Copula-GA framework bridges the gap between advanced energy optimization methodologies and practical accessibility for non-expert building owners. By transforming limited empirical samples into reliable reference models, this research supports building-sector decarbonization. Using three minimal inputs, a building can be matched to one of the 16 standard models to obtain its expected saving rate, payback period, and recommended measures without detailed simulation. Full article

This study examines households’ willingness to participate in the energy transition, with a particular focus on their readiness to invest in energy efficiency measures and modern heating technologies. The research is based on an empirical survey conducted on a representative sample of 1033 households. The Theory of Planned Behavior (TPB) was used primarily as a conceptual and operational framework for organizing survey questions into three theoretically meaningful groups: attitudes, subjective norms, and perceived behavioral control. These determinants were analyzed as precursors of behavioral intention, which is represented by the households’ willingness to invest. The results show that around 30% of households expressed willingness to invest, while the majority were unwilling. The relationships between TPB-related determinants and behavioral intention were examined using chi-square tests, p-values, and Cramer’s V as a measure of association strength. Among the analyzed determinants, attitude-related indicators—willingness to install rooftop solar panels and readiness to accept a reduction in living standards for environmental protection—showed somewhat stronger associations with behavioral intention. Indicators related to subjective norms were statistically significant but weakly associated with behavioral intention. Within perceived behavioral control, only previous investments in building energy retrofits were statistically significant. Full article

Residential buildings are central to decarbonisation because existing dwellings combine long service lives, high heating demand and heterogeneous constraints for retrofitting. This study investigates some retrofit strategies for a terraced house in Oxford, UK, to achieve the winter indoor air temperature set-point while reducing energy use, costs and CO₂ emissions. A calibrated dynamic simulation model was developed from on-site inspections, monitored temperatures, occupant schedules and energy-bill data. The analysis compares baseline configuration with scenarios including radiator power upgrading, envelope insulation, increased internal thermal mass and replacement of the condensing boiler with a high-temperature ground-source heat pump (GSHP). The results show that radiator upgrading enables the most critical rooms to reach the 20 °C set-point, while envelope insulation reduces heating energy and costs. Increased thermal mass improves night-time temperature stability, although its effect on annual energy demand is limited. The GSHP provides the largest primary energy reduction, lowering operational primary energy by 66.3% compared to the reference case and by 70.4% when combined with envelope and thermal-mass measures. Operational CO₂ emissions are reduced by 35.0–84.3%. The study highlights the need to evaluate the capacity of heat emitters, building envelope performance, thermal inertia and heat generator efficiency within a dynamic framework. Full article

Public building retrofit is an important pathway for reducing operational carbon emissions, but evidence-based technology prioritisation remains limited under real-world multi-technology retrofit conditions. This study develops an interpretable data-driven framework to identify priority technologies and technology co-adoption patterns for public buildings in China’s Hot Summer and Cold Winter (HSCW) region. Based on 218 completed retrofit projects, the carbon reduction rate (CRR) was used as the performance indicator, and 15 retrofit technologies were analysed using FDR-adjusted Mann–Whitney U tests, repeated-validation XGBoost–SHAP analysis, and Apriori association-rule mining. The projects showed substantial variation in CRR, with a mean of 24.98% and a median of 21.70%. Across five repeated 5-fold cross-validations, the predictive XGBoost model achieved a mean R² of 0.417 and a mean RMSE of 0.127. Roof insulation, external wall insulation, and ventilation system retrofit showed the strongest combined evidence and were classified as core technologies. Apriori analysis further revealed three empirical co-adoption patterns: integrated passive-envelope retrofit, solar-control and renewable-energy integration, and operational-management improvement. The findings suggest that retrofit planning in the HSCW region should prioritise envelope insulation and ventilation performance, while selecting shading, system, renewable-energy, and operational-control measures according to project-specific conditions. Full article

Under China’s “carbon peaking before 2030 and carbon neutrality before 2060” targets, the low-carbon transformation of the ironmaking stage—which contributes approximately 70% of the CO₂ emitted per ton of steel in the dominant blast furnace–basic oxygen furnace (BF–BOF) route—is decisive for decarbonizing the steel industry. In contrast to earlier reviews that describe individual technologies in isolation, this review provides a structured, cross-technology synthesis: the main routes are classified into short-/medium-term low-carbon blast furnace technologies (hydrogen-rich carbon-recycling oxygen blast furnace, hydrogen-rich injection, biomass char injection and ultimate energy-efficiency measures) and medium-/long-term non-blast furnace technologies (hydrogen-based shaft furnace direct reduction, smelting reduction, rotary hearth furnace, fluidized-bed reduction and electric smelting reduction) and are then compared on a common set of quantitative indicators—CO₂ mitigation, specific energy and hydrogen demand, technology readiness level (TRL) and relative cost. On this basis, emerging hydrogen-based flash ironmaking, developed from the interdisciplinary integration of “iron and steel–non-ferrous metallurgy–hydrogen metallurgy–plasma”, is critically assessed, with a clear separation between laboratory/pilot feasibility and industrial readiness. We conclude that low-carbon blast furnace technologies, owing to low retrofit cost and high maturity, will dominate near-term mitigation, whereas hydrogen-based shaft furnaces and, in the longer term, hydrogen-based flash ironmaking define the pathway toward near-zero-carbon ironmaking—conditional on the availability of green hydrogen and low-carbon electricity and on overcoming key engineering barriers. Full article

Green remodeling projects for public buildings in South Korea aim to improve the energy performance of aging facilities, with a policy target of achieving at least 30% energy savings. Because the 30% saving rate functions as a key policy benchmark, it is necessary to identify why some projects achieve higher savings while others remain below the target. This requires a comparative analysis of energy-saving levels in relation to baseline energy-use composition and retrofit measure applications. This study analyzes the 1954 preliminary investigation and ECO2-OD-based assessment cases of public building green remodeling projects to examine energy-saving levels, baseline energy-use composition, end-use contributions, and retrofit measure applications. Pre- and post-retrofit primary energy demand for heating, cooling, domestic hot water, and lighting were used to calculate energy-saving rates. Based on the 30% policy target, the cases were classified into Low-saving, Target-achieving, High-saving, and Very-high-saving levels. The average energy-saving rate was 36.02%, but 39.61% of cases remained below the 30% target. Higher-saving groups showed greater baseline heating energy shares, increasing from 53.38% in the Low-saving group to 66.18% in the Very-high-saving group, suggesting an association between pre-retrofit energy-use structure and predicted retrofit potential under the ECO2-OD assessment framework. Heating was also the dominant contributor to total savings, with its contribution rising from 17.07 to 44.94 percentage points. Higher-saving cases tended to involve more comprehensive retrofit packages combining envelope, system, and lighting improvements. These findings suggest that energy-saving targets and retrofit strategies should consider baseline end-use energy composition and establish differentiated saving targets according to building characteristics, rather than relying only on uniform policy targets and average project performance. Full article

Improving the energy performance of historical buildings is a key challenge for decarbonising the European built environment. In the Mediterranean context, retrofit design is especially complex because interventions must reduce heating and cooling demand while preserving architectural and cultural values. Although research on this topic has grown, available evidence remains fragmented, with studies often focused on individual case studies and isolated retrofit packages. This review systematises the literature on energy retrofit interventions for historical buildings in the European Mediterranean region by linking retrofit measures, energy outcomes and conservation constraints. A PRISMA-based workflow was used to select articles published between 2010 and 2025 from Scopus and Web of Science. The results show a predominance of envelope-based measures, often combined with HVAC improvements. Passive–active packages achieve the highest reported reductions, up to 87% for heating and 75% for cooling. Conservation constraints do not necessarily prevent energy improvement, but they influence the admissibility, location and invasiveness of retrofit measures. Overall, the evidence indicates that energy retrofit of Mediterranean historical buildings should focus on heating reduction, cooling resilience and hygrothermal safety. The review provides a framework for identifying compatible retrofit pathways according to the architectural and material transformability of historical buildings. Full article

Existing urban residential buildings contribute substantially to operational energy use and carbon emissions in the building sector, making low-carbon retrofitting a key approach to improving the performance of the existing housing stock. This study conducts a bibliometric and systematic review of research on low-carbon retrofitting of existing urban residential buildings in China. Journal articles published between 2015 and 2025 were retrieved from Web of Science and Scopus, and 91 studies were retained after screening. Bibliometric analysis was used to examine annual publication trends, source distribution, keyword co-occurrence, thematic evolution, and organizational collaboration. The systematic review further synthesised evidence on retrofit policies, technical measures, and performance evaluation methods. The results indicate a clear increase in publications in recent years, with research attention shifting from basic energy-saving measures towards multi-objective optimization, carbon reduction, and thermal comfort improvement. The review suggests that China’s residential retrofit policies can be understood as a multi-level framework supporting retrofit implementation. Retrofit strategies have gradually shifted from individual measures towards integrated retrofit packages, while performance evaluation has expanded from energy-saving assessment to broader considerations of carbon emissions, occupant comfort, and economic feasibility. The review highlights the need for more consistent evaluation boundaries, stronger integration of lifecycle carbon accounting and occupant behaviour, and climate-responsive retrofit strategies. These findings provide a structured basis for comparing retrofit approaches, strengthening the connection between policy and technology, and supporting decision-making in large-scale residential retrofit programmes. Full article