Search Results (136)

This work presents an on-field noise analysis during the class breaks in Greek school units (a high school and a senior high school) based on the design and deployment of low-cost IoT sensor nodes and IoT platforms. The course breaks form 20% of a regular school day, during which intense mobility and high noise levels usually evolve. Indoor noise levels, along with environmental conditions, have been measured through a wireless network that comprises IoT nodes that integrate humidity, temperature, and acoustic level sensors. PM₁₀ and PM_2.5 values have also been acquired through data sensors located nearby the school complex. School buildings that have been recently renovated for minimizing their energy footprint and CO₂ emissions have been selected in comparison with similar works in academia. The data are collected, shipped, and stored into a time-series database in cloud facilities where an IoT platform has been developed for processing and analysis purposes. The findings show that low-cost sensors can efficiently monitor noise levels after proper adjustments. Additionally, the statistical evaluation of the received sensor measurements has indicated that ubiquitous high noise levels during the course breaks potentially affect teachers’ leisure time, despite the thermal isolation of the facilities. Within this context, we prove that the proposed IoT Sensor Network could form a tool to essentially monitor school infrastructures and thus to prompt for improvements regarding the building facilities. Several guides to further mitigate noise and achieve high-quality levels in learning institutes are also described. Full article

The pyrolysis of non-recyclable construction, renovation, and demolition (CRD) wood waste is a complex thermochemical process involving devolatilization, diffusion, phase transitions, and char formation. CRD wood, a low-ash biomass containing 24–32% lignin, includes both hardwood and softwood components, making it a viable heterogeneous feedstock for bioenergy production. Thermogravimetric analysis (TGA) of CRD wood residues was conducted at heating rates of 10, 20, 30, and 40 °C/min up to 900 °C, employing model-fitting (Coats–Redfern (CR)) and model-free (Ozawa–Flynn–Wall (OFW), Kissinger–Akahira–Sunose (KAS), and Friedman (FM)) approaches to determine kinetic and thermodynamic parameters. The degradation process exhibited three stages, with peak weight loss occurring at 350–400 °C. The Coats–Redfern method identified diffusion and phase interfacial models as highly correlated (R² > 0.99), with peak activation energy (E_a) at 30 °C/min reaching 114.96 kJ/mol. Model-free methods yielded E_a values between 172 and 196 kJ/mol across conversion rates (α) of 0.2–0.8. Thermodynamic parameters showed enthalpy (ΔH) of 179–192 kJ/mol, Gibbs free energy (ΔG) of 215–275 kJ/mol, and entropy (ΔS) between −60 and −130 J/mol·K, indicating an endothermic, non-spontaneous process. These results support CRD wood’s potential for biochar production through controlled pyrolysis. Full article

In recent years, China has continuously increased the construction of sports facilities, with the number and area of sports venues steadily growing. The use of more energy-efficient ventilation methods in gymnasiums has become one of the research hotspots. Taking a multi-functional gymnasium in Wuhan as an example, the gymnasium adopts a seat air supply device driven by natural wind to enhance indoor ventilation. This study uses the methods of field measurement and CFD simulation to analyze the application effect of this new type of natural ventilation device in hot summer and warm winter areas during the transition season. Through CFD simulation of the ventilation performance of the seat air supply at different opening rates, the indoor ventilation effect and thermal comfort were analyzed. The application of the seat air supply greatly improved the indoor environment and enhanced the comfort of personnel. After turning on the seat air supply, the maximum temperature difference between the indoors and outdoors increased from 1.7 °C to 3.4 °C, the natural air intake rate increased from approximately 50% to approximately 70%, the wind speed in the seat area significantly increased, the uniformity of the wind speed field in the movement area significantly increased, and the proportion of areas with low wind speed and no wind speed decreased to 9.6%. The proportion of areas with wind speeds ranging from 0.3 to 0.5 m/s increased from 8.8% to 33.0%. At 10:00 a.m., the temperature at the indoor station was relatively low. The opening of the seat air supply device reduced the PMV value of the front seats by an average of 0.39. When the indoor platform temperature reached the maximum value, the impact of equipment activation on the PMV index of the seat area was relatively small, with an average reduction of only 0.19. The research results show that the application of a natural wind-driven seat air supply in sports venues is very promising, providing a new idea for the energy-saving renovation of gymnasiums and effectively promoting the development of low-carbon undertakings. Full article

In the global low-carbon era, building energy conservation has achieved significant success. However, especially in the culture and tourism industry, there are many brick–wood buildings that imitate ancient styles. As their appearance authenticity and structural safety must be maintained, energy-saving retrofits face multiple constraints. For such buildings, regulating building energy consumption through the renovation of the enclosure structure has practical value in supporting the achievement of carbon peaking and carbon neutrality goals. This study addresses the contradiction between the preserving architectural forms and improving energy efficiency in the energy-saving renovation of brick–wood buildings that imitate ancient styles. It presents a “Three-Micro” technical system grounded in the minimum-intervention principle, integrating micro-intervention implantation, micro-realignment regulation, and micro-renewal iteration. Through modular node design, it combines traditional construction with modern energy-saving techniques and systematically devises an energy-saving retrofit plan for such existing buildings. Through simulation and verification using the case of the Northwest Corner Tower in the Imperial City of Shengjing, the results show that the energy-saving rate of the building itself is 58.47%, while the comprehensive energy-saving rate is 87.56%. Both meet the evaluation criteria for ultra-low energy consumption buildings under the relevant standards, which proves the feasibility of the “Three-Micro” technical system. It provides solutions for the energy-saving renovation of similar buildings, especially those brick–wood buildings that imitate ancient styles and have a high degree of completion (a high level of imitation of ancient architecture). At the same time, it also holds important reference value for the energy-saving renovation of some non-core ancient buildings that are commonly used in everyday life, such as those serving as ticket offices, exhibition halls, administrative offices, etc. Full article

This study explores renovation strategies for green spaces in aging residential communities in cold regions, with a particular focus on enhancing carbon sequestration capacity and residents’ well-being. Under the framework of the “dual carbon” goals, a combination of literature analysis and resident surveys reveals that (1) the existing layouts of green spaceand plant selections have not fully considered their carbon sequestration potential, leaving significant room for optimization; (2) low outdoor temperatures, the lack of heating facilities, and monotonous winter landscapes contribute to reduced green space utilization, limiting outdoor activities and diminishing the health benefits of green spaces; and (3) the integration of glass sunrooms with renewable energy systems, such as photovoltaic power generation, can effectively improve winter green space utilization, regulate micro climates, and enhance vegetation-based carbon sequestration while also providing residents with comfortable spaces for social interaction and wellness activities. The findings indicate that scientifically optimizing green space layouts, selecting plant species with high carbon sequestration potential, and incorporating climate-adaptive architectural designs can significantly enhance the ecological value of green spaces and residents’ quality of life. It is recommended that future community renewal initiatives integrate green technologies, policy support, and interdisciplinary collaboration to promote low-carbon and livable urban development. Full article

Green remodeling and retrofitting are effective strategies for enhancing the sustainability of existing buildings. While green remodeling involves significant structural modifications, green retrofitting typically focuses on improving energy efficiency and reducing environmental impact. However, easy-to-implement green retrofit technologies can be particularly valuable for low-income communities, offering a more affordable way to upgrade residences without extensive renovations. This paper analyzed the effectiveness of newly developed, easy-to-implement green retrofit technologies for windows in reducing heating energy use and greenhouse gas emissions. We conducted experiments using secondary glazing and windproof materials to enhance the thermal insulation and air-tightness performance of a residential building. Subsequently, we simulated the effectiveness of these green retrofit technologies under various conditions for residential buildings. In addition, we analyzed utility bills using data collected from residents. Our findings demonstrated an average reduction of 10–15% in heating energy consumption through the implementation of these green retrofit technologies for windows in older residential buildings. Full article

This study investigates window renovation strategies for a detached building in Belper, UK, analyzing double- and triple-glazed, vacuum, and low-E vacuum windows with varying gas fillings, pillar radii, and spacing. The results reveal that increasing glass layers reduces energy consumption, while a larger pillar radius decreases efficiency. More pillars improve window performance. For windows with the same U-value, a higher SHGC enhances energy efficiency by maximizing solar heat gain, particularly in colder climates. Conversely, reducing the U-value while maintaining a constant SHGC enhances insulation and minimizes heat loss. The study emphasizes the necessity of balancing U-value and SHGC for optimal window performance in different climates. The most effective strategy involves using a low-E vacuum window with a 0.25 mm pillar radius and 40 mm spacing while doubling the south-facing window area, leading to a 7.01 GJ heating load reduction—a 27.9% improvement over modifying the window type alone. Additionally, a key ratio, SHGC/(U_window − U_wall), is introduced to assess window size modifications. The results indicate that enlarging windows is beneficial when solar heat gain surpasses additional heat loss, underscoring the importance of balancing heat conduction and solar energy utilization in energy-efficient building design. Full article

The construction industry is facing an increased demand to adopt sustainable green building materials to minimize the carbon footprint. Hemp concrete is a green building material not only because of its low embodied carbon but also because of its ability to regulate heat and relative humidity. Its thermal characteristics are often viewed as favorable for reducing the energy used to heat or cool indoor buildings. The current research is focused on the properties of hemp concrete from Slovak manufacturers which can be effectively used in construction as a replacement for conventional building materials and can also be effectively applied in building renovations. The basic thermal properties of hemp concrete, i.e., specific heat capacity, thermal conductivity, effusivity, thermal diffusivity, and lag time, were determined. The determination of all properties is dependent on the knowledge of heat fluxes at the surface and the density of samples. The insulation ability was expressed with a thermal conductivity of 0.099 W·m⁻¹·K⁻¹. The accumulation was expressed with a specific heat of 1540 J·kg⁻¹·K⁻¹ and density of 322 kg·m⁻³ in the air environment temperature of 22 °C and relative humidity of 50%. To assess moisture properties, the moisture content and the speed of molecules during diffusion and lag time, based on the thickness of the hemp concrete samples, were measured. The speed of water molecules during diffusion in hemp concrete was 8.6 × 10⁻⁷ m·s⁻¹. The study shows that hemp concrete has interesting hydrothermal properties for use as an insulation layer in envelope structures. Thus, this material can be used effectively in the construction field in order to meet the requirements of the current standards, which aim to reduce energy and environmental impacts. Full article

Countries around the world have developed standards for ultra-low energy consumption building design and future plans. Unfortunately, these standards lack specific requirements for industrial heritage. As an important carrier of urban context, history, and the transmission of residents’ memories, industrial heritage cannot be overlooked in urban development. This study uses DesignBuilder energy simulation software to model industrial heritage (taking the Changchun Tractor Factory as an example) and compares the energy consumption before and after renovation strategies. The results show that in the Case 4 plan, after implementing the renovation strategy, heating energy consumption can be reduced by about 11,648 (kWh/m²) over the heating season, the total primary energy was reduced by about 4 million (kgce/tce), and total energy consumption decreases by approximately 95%. This demonstrates the effectiveness of the industrial heritage reuse design strategy proposed in this paper. It provides a new direction for reuse design under ultra-low energy consumption requirements in related case studies. Full article

The European Union aims to achieve climate neutrality by 2050, prioritizing energy efficiency particularly in the building sector. Despite significant policies, such as the EU Green Deal and Renovation Wave initiative, the rate of deep energy renovations remains insufficient, with only 0.2% annually versus the 3% required. Multiple barriers hinder the progress of deep energy renovations (DERs), including fragmentation among stakeholders, the limited coordination of RDI (Research, Development, and Innovation) efforts, and a lack of systemic approaches. The objective of this paper is to illustrate a holistic methodological approach for enhancing the DER market uptake based on transition pathways theory (TPT) and is designed to drive structural evolution in DER markets aimed at overcoming their main current constraints. To this end, five key transition pathways are outlined—namely institutionalization, clusterization, capitalization, digitalization, and exploitation—and are conceived for fostering coordination, integration, promotion, and efficient scaling of innovations along the whole DER value chain. This approach was tested in seven EU building market ecosystems under the H2020 re-MODULEES project, aimed at developing a market activation platform conceived as a digital enabler for next-generation One-Stop Shops (OSSs). This project yielded practical evidence on the potentiality of the TPT frame to strengthen and empower local ecosystems through stakeholders’ engagement and cooperation. The findings suggest that the TPT-based approach tested in re-MODULEES can effectively address structural challenges in diverse DER renovation markets, and for this reason, it may be also tested and extended in other ecosystems across Europe in order to be validated as a strategic approach at the EU level for facilitating the transition to low-carbon buildings. Full article

The selection of insulation materials during the renovation of enclosure structures in old communities significantly impacts project quality, cost, and carbon emissions. Many insulation materials currently in use only meet energy-saving standards as required by design specifications, often neglecting important aspects such as ancillary construction materials, construction techniques, and environmental protection. Furthermore, they fail to adequately address the unique characteristics of old communities. This study establishes a performance evaluation framework for low-carbon insulation materials in old community enclosures, assessing their suitability from four dimensions: technical performance, economic benefits, social impact, and environmental standards. By introducing the attribute hierarchy model (AHM), subjective weights are determined, while objective weights are obtained using the entropy method and variation coefficient method. A combination of subjective and objective weights are then applied to create a scientific and rational comprehensive evaluation model. The evaluation of insulation materials is conducted using a combination of the matter–element extension method and the cloud model. A case study of a specific old community retrofit project demonstrates that the use of Expanded Polystyrene (EPS) as the insulation material is more suitable for the low-carbon retrofit of the enclosure structures. The results indicate that the proposed evaluation system is both applicable and effective for similar projects. Full article

This paper investigates the environmental and economic impacts of energy-efficient renovations, specifically focusing on the integration of photovoltaic (PV) systems in a public kindergarten. Leveraging the VERIFY platform, this study employs Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) methodologies to evaluate building performance over a 25-year analysis period under three distinct scenarios: a low-usage period during the COVID-19 pandemic (2021), a normal-usage period under post-pandemic conditions (2024) with the realized investment, and a hypothetical scenario with a PV installation size that allows for appropriate reductions alongside favorable financial outcomes. The pandemic-induced occupancy reduction led to atypical energy demand patterns, with lower self-consumption and increased electricity exports to the grid, affecting the financial viability of PV investments. By incorporating post-pandemic operational data, a meaningful comparison of energy efficiency measures under constrained and stable operating conditions is conducted, addressing the impact of fluctuating demand on long-term energy investment sustainability. The results highlight that system sizing and energy reconciliation policies (net metering, net billing) significantly influence financial outcomes. The PV system achieved a Levelized Cost of Electricity (LCOE) of EUR 0.0811–0.0948/kWh, with payback periods ranging from 6.01 to 14.66 years, depending on operational intensity. The findings demonstrate that while PV systems contribute to emission reductions and cost savings, their economic feasibility depends on occupancy stability and policy frameworks. This study provides insights for optimizing renewable energy investments in public buildings, demonstrating the importance of considering dynamic operational conditions in lifecycle assessments. Full article

As the dual carbon goals are being approached, there has been an increase in the number of energy-saving renovation projects for existing buildings. However, building renovation also brings about environmental impacts and incremental costs, which need to be addressed urgently. This study proposes an integrated artificial intelligence framework to facilitate multi-criteria energy renovation decision making by combining a surrogate-based machine learning (ML) model and an evolutionary generative algorithm to efficiently and accurately identify optimal renovation strategies. To enhance the robustness of the methodology, a comparative analysis of four different ML models—light gradient boosting machine (LightGBM), fast random forest (FRF), multivariate linear regression (MVLR), and artificial neural network (ANN)—was conducted, with LightGBM demonstrating the best performance in terms of accuracy, adaptability, and efficiency. Using the heuristic optimization algorithm and entropy-weighted method, the framework achieved average energy savings of 56.62%, a reduction in carbon emissions of 51.60%, and a 24.27% decrease in life-cycle costs. Compared to local ultra-low-energy building standards, the optimal solutions resulted in a 2.60% reduction in carbon emissions and a 15.85% decrease in life-cycle costs. This integrated framework demonstrates the potential of combining machine learning surrogate models, evolutionary generation, and entropy-weighted methods in building energy retrofitting optimizations, offering a novel, efficient, and adaptable approach for researchers and practitioners seeking to balance energy consumption, carbon emissions, and life-cycle costs in renovation projects. Full article

Retrofitting existing buildings is a cornerstone of Europe’s strategy for a sustainable built environment. Therefore, accurate short-term forecasts to evaluate policy impacts and inform future strategies are needed. This study investigates the short-term predictive modelling of renovation activity in Belgium, focusing on overall renovation activity (RA) and energy-specific renovation activity (EA). Using data from 2012 to 2023, linear modelling was employed to analyze the relationships between RA/EA and macroeconomic indicators, market confidence, building permits, and loan data, with model performance evaluated using Mean Absolute Percentage Error (MAPE). Monthly data and time lags of up to 24 months were considered. The three best-performing models for RA achieved MAPE values between 2.9% and 3.1%, with validated errors ranging from 0.1% to 4.1%. For EA, the best models yielded MAPE values between 4.4% and 4.6% and validated errors between 8.9% and 14%. Renovation loans and building permits emerged as strong predictors for RA, while building material prices and loans were more relevant for EA. The time lag analysis highlighted that renovation processes typically span 15–24 months following loan approval. However, the low accuracy observed for EA underscores the need for further refinement. This explorative effort forms a solid base, inviting additional research to enhance our predictive capabilities and improve short-term modelling of the (green) residential renovation market. Full article

Energy Efficiency Contracting (EEC) enables structural improvements in buildings by financing upgrades through the savings generated, eliminating the need for upfront investment by property owners. Although the model supports the energy transition and the reduction in GHG emissions, its adoption in the private sector faces relevant barriers such as the lack of information from the Energy Service Companies (ESCOs), distrust from clients in benefits with no upfront costs, and legal and behavioral barriers. To overcome these challenges, the FinSESCo platform, funded by Era-Net 2020 joint call, aims to channel private investments into building renovations and renewable energy installations via a crowdfunding portal. The platform allows individuals and organizations to finance small-scale renewable energy installations and energy efficiency measures for homeowners, tenants, and apartment owners. The new platform is likely to change the way EE investments are made and reach out to new audiences. A survey of 2585 German households sought to understand the drivers of EE investments, factors affecting the decisions, and their relationships with several demographic variables. Using a stepwise backward regression model, the study found significant differences between traditional investors in EE and those who would use the FinSESCo platform. Low- and medium-income households were more likely to take up the platform, and previous renewable energy ownership, experience with EEC models, and knowledge of crowdfunding further raised willingness to participate. The results point to the potential of the FinSESCo platform to expand EEC to new audiences, underlining its role of democratization and diversification of investments in building energy efficiency. Full article