Search Results (158)

To enhance the sustainability of temporary office buildings, energy-saving and emissions-reduction technologies, as well as the optimization of photovoltaic (PV) energy storage systems in such structures, are of great importance. In this study, a distributed energy storage system was developed for a temporary office building in Jincheng, China. Measurements showed climatic factors had the greatest effect on building energy consumption due to the building envelope’s low thermal performance and airtightness. The air conditioning system accounted for the highest proportion (87%) of building energy consumption. The PV system’s peak output occurred in the morning due to illumination conditions and module orientation. On this basis, a time-of-use (TOU)- and state-of-charge (SOC)-aware scheduling strategy was developed for the PV-ESS of the temporary office building to improve renewable-energy utilization and reduce user-end electricity cost. Unlike purely theoretical optimization studies, this work focuses on the practical application and validation of the scheduling framework in a real temporary office building using monitored data. The electricity cost decreased by 0.3 RMB/kWh, and the revenue from electricity sales during the scheduling period increased by 0.03 RMB/kWh after model optimization. The optimized scheduling strategy resulted in significantly fewer charge–discharge cycles of the storage battery, substantially decreasing the battery’s storage capacity and the system’s investment costs. Full article

This research investigates the air permeability and watertightness performance of commercially available windows and doors based on laboratory tests conducted in accordance with the EN 1026 and EN 1027 standards. All tests were carried out under controlled environmental conditions, and the results were validated following relevant ISO procedures to ensure reliability and consistency. The tests are essential for evaluating the air permeability and watertightness of commercial windows and doors to ensure the overall performance, energy efficiency, and durability of the building envelope. The results provided consist of 244 samples (93 doors and 151 windows) tested between 2018 and 2025 in an accredited laboratory complying with EN ISO/IEC 17025. The results show that most doors achieved the highest air permeability class (Class 4) according to EN 12207, with shares ranging from 50% to 80% and exceeding 65% in most years. Window performance was similarly strong, with more than 74% of samples classified as Class 4, indicating consistently high airtightness and compliance with stringent energy efficiency requirements. Watertightness tests revealed that 59% of products were resistant to water penetration, while 41% were permeable. Among watertight products, windows predominated (67%), while doors accounted for a larger share of water-permeable cases. The results support informed decision making in manufacturing, construction practices, and early-stage building design, contributing to improved building durability and energy efficiency. Full article

Energy performance certification of buildings is a key instrument for assessing energy efficiency within the framework of the Energy Performance of Buildings Directive (EPBD). In practice, significant discrepancies are often observed between the predicted and actual energy performance of buildings. One of the main causes of this discrepancy is non-compliance with technological procedures during construction. This paper analyses the energy and economic consequences of such deviations through a case study of a newly constructed residential building in northern Slovakia that was originally certified in the A0 energy class. The research methodology included in situ inspection of the building, thermographic measurements, destructive probes of the building envelope, analysis of project documentation, and recalculation of energy performance using measured building parameters. The results revealed significant deficiencies in the thermal insulation of the building envelope, roof construction, and window airtightness. After recalculation based on measured parameters, the building’s energy classification deteriorated from A0 to B. The total energy demand increased by 46%, while primary energy demand increased by 141%. The results demonstrate that construction deviations can significantly affect the reliability of energy performance certification. The study highlights the importance of verifying the actual condition of buildings during construction to ensure the reliability of EPC assessments. Full article

With the increasing number of highly airtight residences, concerns have risen that the negative pressure formed indoors during kitchen hood operation can reduce capture performance and cause unintended infiltration. This study experimentally and numerically (via CFD simulations) examined whether installing an air supply unit on the cooktop beneath a hood can stabilize hood performance and suppress infiltration in small residential spaces. Two cases were established depending on whether air was supplied: Case 1 (hood operation only) and Case 2 (simultaneous operation of the hood and the air supply unit). In the experimental setup, the hood exhaust flow rate, supply airflow rate, sink-drain infiltration rate, and temperature/humidity were measured. The period during which variations in measured values remained within 10% was defined as the steady state. In the CFD analysis, winter conditions were assumed, and the measured values were applied to the wall boundary, after which the temperature and velocity field were analyzed. In Case 2, by supplying 24.11 CMH of air, the hood flow rate remained stable at 75.72 CMH (98.8% of the initial level) throughout the test, and no infiltration was detected. The CFD analysis revealed that the air supply unit generated an “air curtain” effect, enabling rapid capture of hot airflow and reducing the high-temperature region. In conclusion, the interconnected operation of supply and exhaust systems was shown to be effective in enhancing hood exhaust stability, suppressing unintended infiltration, and improving capture reliability in highly airtight small residential buildings. Future studies should include further analyses, such as the effects of actual cooking behaviors and leakage path distributions. Full article

This study addresses the challenge of rapid identification and assessment of localized damage to building envelopes under resource-constrained conditions—specifically, the absence of specialized inspection equipment—with a particular focus on the detrimental effects of such damage on thermal performance and energy efficiency. An efficient detection methodology tailored to small-scale maintenance scenarios is proposed, leveraging the YOLOv11 object detection architecture to develop an intelligent system capable of recognizing common envelope defects in contemporary residential buildings, including cracks, spalling, and sealant failure. The system prioritizes the detection of anomalies that may induce thermal bridging, reduced airtightness, or insulation degradation. Defects are classified according to severity and their potential impact on thermal behavior, enabling a graded, integrated repair strategy that holistically balances structural safety, thermal restoration, and façade aesthetics. By explicitly incorporating energy performance recovery as a core objective, the proposed approach not only enhances the automation of spatial data processing but also actively supports the green operation and low-carbon retrofitting of existing urban building stock. Characterized by low cost, high efficiency, and ease of deployment, this method offers a practical and scalable technical pathway for the intelligent diagnosis of thermal anomalies and the enhancement of building energy performance. It aligns with the principles of high-quality architectural development and sustainable building governance, while concretely advancing operational energy reduction in the built environment and contributing meaningfully to energy conservation goals. Full article

Indoor exposure to particulate matter (PM_2.5 and PM₁₀) remains a significant public health problem, especially in high-traffic areas, where outdoor pollution, building characteristics, and user activity jointly influence indoor air quality. This study aims to synthesise and compare the effectiveness of key technical solutions to reduce indoor PM concentrations in different types of buildings. A comprehensive review and comparative analysis of published experimental and field studies were conducted, covering residential, educational, office, medical, sports, and heritage buildings. The interventions evaluated included mechanical ventilation and filtration systems, portable HEPA air cleaners, integrated building envelope solutions, airflow optimisation strategies, and selected auxiliary technologies. Reported performance metrics such as baseline indoor and outdoor PM concentrations, air exchange rate (ACH), filter class, clean air delivery rate (CADR), and percentage reduction were systematically analysed. The results indicate that mechanical filtration, particularly high-efficiency HVAC (Heating Ventilation and Air-Conditioning) systems and HEPA filters, provide the most reliable and repeatable reductions in PM_2.5 and PM₁₀, especially under controlled airflow and recirculation conditions. Integrated approaches that combine airtight building envelopes, mechanical ventilation, and local air purification achieved the highest overall effectiveness. The findings confirm that successful PM mitigation requires context-specific multicomponent strategies tailored to building type, outdoor pollution load, occupancy, and ventilation design. Full article

Improving the energy efficiency of Australia’s ageing housing stock is critical to achieving national decarbonisation and climate resilience goals. Although houses built prior to the introduction of national energy efficiency regulations in the 1990s are commonly assumed to be thermally inefficient, empirical evidence for their performance under Australian climatic conditions remains limited, particularly for prevalent pre-war construction typologies. This study addresses this gap by examining the thermal comfort and energy demand of a representative double-brick house built in the 1930s in Adelaide, Australia. A combined methodology was adopted, integrating long-term environmental monitoring, occupant responses, and building performance simulations conducted in two stages. The first stage evaluated the existing building’s thermal and energy performance to establish a calibrated baseline, while the second stage applied parametric optimisation analysis to assess potential retrofit strategies. Baseline results indicate that the case-study dwelling exhibits strong passive cooling performance in summer, challenging the prevailing assumption that older Australian houses are inherently thermally inefficient. Building on this calibrated baseline, parametric optimisation of 467 retrofit configurations was undertaken and benchmarked against the Australian Nationwide House Energy Rating Scheme (NatHERS). The results show that a combined strategy of increased insulation, reduced infiltration, upgraded glazing, and optimised external shading can reduce total heating and cooling loads by up to 78% compared to the original condition, achieving energy ratings of up to 8.5 NatHERS Stars. The findings demonstrate a transferable workflow that links empirical performance assessment with simulation-based optimisation for evaluating retrofit options in older housing typologies. For pre-war double-brick houses in warm-temperate climates, the results indicate that prioritising airtightness and glazing upgrades offers an effective and feasible retrofit pathway, supporting informed decision-making for designers, owners, and policymakers. Full article

In recent decades, significant efforts have been devoted to constructing energy-efficient buildings, providing comfortable indoor environments. However, measures such as enhanced airtightness, while reducing infiltration through the building envelope, might consequently reduce natural ventilation. This reduction is a critical concern because natural ventilation is an essential factor in controlling indoor air quality (IAQ), and its diminution could therefore worsen IAQ. Sick building syndrome has emerged as a term used to describe health hazards linked to the time spent indoors but with no particular cause. Since people spend most of their time indoors, the demand for continuous and real-time IAQ management to reduce human exposure to pollutants has increased considerably. In this context, low-cost sensors (LCS) for IAQ monitoring have become popular, driven by recent technological advancements and increased awareness regarding indoor air pollution and its negative health impacts. Although LCS do not meet the performance requirements of reference and regulatory equipment, they provide informative measurements, offering high-resolution monitoring, emission source identification, exposure mitigation, real-time IAQ assessment, and energy efficiency management. This perspective article proposes a general model for LCS systems (and subsystems) implementation and presents a prospective analysis of their strengths and limitations for IAQ management, reviews the literature regarding sensor system technologies, and offers design recommendations. It provides valuable insights for researchers and practitioners in the field of IAQ and discusses future trends. Full article

Fire safety is a crucial issue for buildings, especially with the rise of modular construction, which demands materials that combine lightness with mechanical performance and stability. This study investigates a new concept for single-story modular constructions, made up of 3D cells assembled from thermally and acoustically pre-insulated concrete panels. These panels comprising four walls and two slabs forming the module, are stiffened, with thicknesses of only 5 cm for the walls and 7 cm for the slabs. Their constituent material is a self-compacting, high-volume steel-fiber concrete, containing 80 kg/m³ of steel fibers and 0.3 kg/m³ of polypropylene fibers. Experimental tests on a full-scale wall and slab revealed that adding 0.3 kg/m³ of polypropylene fibers effectively prevents concrete from splintering and achieves the necessary 30 min fire resistance. Standardized full-scale fire tests on walls and slabs confirmed that these thin structures meet fire resistance, insulation, and airtightness standards. The high volume of steel fibers provides ductility, maintaining structural integrity despite concrete spalling. The maximum spalling depth observed in some areas ranged 35 to 50 mm, without compromising structural performance. Overall, the modular system satisfies the fire safety requirements for structural stability (no collapse) and performance in single-story modular construction. Full article

This study presents a monitoring-calibrated, systems-level retrofit assessment for a 15-year-old Grade-A office building in Beijing, China (temperate monsoon climate). One year of continuous monitoring (2023–2024) was combined with calibrated multi-physics simulations (EnergyPlus/DesignBuilder, Radiance, representative CFD) to evaluate retrofit scenarios for lighting, envelope and HVAC systems. Baseline EUI = 108 kWh·m⁻²·yr⁻¹ (total site electricity ≈ 3,088,893 kWh·yr⁻¹). HVAC accounted for ≈48% of site electricity. Key findings: (1) LED lighting retrofit delivered measured lighting savings of ~26.7% (simulated potential up to ~32.7%) but may increase cooling loads in some operating regimes (simulated +8.3%) if not coordinated with HVAC and envelope measures; (2) glazing upgrades and airtightness improvements materially increase HVAC savings; (3) a prioritized, phased retrofit (lighting → envelope → HVAC) can capture ~80–85% of integrated carbon reductions while lowering immediate CAPEX and business disruption; (4) scheduling major HVAC upgrades before the cooling season and envelope works during transitional months improves operational and economic outcomes. Calibration and uncertainty metrics are reported (annual energy error < 5%). Full article

Amid the combined pressures of global carbon-reduction in architecture and the imperative of cultural heritage conservation, new courtyard-style buildings in hot-summer and cold-winter regions face a dual challenge of reconciling historical morphological constraints with contemporary comfort requirements. At the same time, the prevailing energy-efficiency codes in these regions, emphasizing high airtightness and strong insulation, have revealed shortcomings such as poor indoor air quality and insufficient summer ventilation. This study takes the Lu Residence in Dongyang, Jinhua, Zhejiang Province, as the primary case. It systematically examines the coupling mechanisms between the geometric configurations of transitional space in traditional courtyard dwellings and their environmental physical parameters using field surveys, multi-parameter environmental monitoring, and computer simulations. The results identify the optimal orientations and geometric parameters that balance summer ventilation with winter thermal buffering in hot-summer and cold-winter regions. The primary conclusions of this research are as follows: (1) The optimal orientation for axial buildings lies between 15° west of south and 15° east of south, as well as 30–60° east or west of south, with an angle of 45–60° in relation to the prevailing annual wind direction for all buildings. (2) The optimal height-to-width ratio of the courtyard is less than 1:2.5, while the range of the length-to-width ratio extends from 1:0.5 to 1:0.7. (3) The optimal eave depth varies from 900 to 1500 mm, effectively balancing winter heat retention and summer shading; however, a depth of 2400 mm is primarily advantageous for shading purposes. Furthermore, these findings are applied to the design of a new guesthouse within the conservation area of the Xu Zhen Er Gong Ancestral Hall in Yongkang, establishing a climate–geometry matching mechanism for transitional spaces. The study demonstrates that transitional space can serve as effective passive regulators, offering a scientific and sustainable pathway for the adaptive continuation of traditional courtyard architecture. Full article

A rapid review was undertaken to consider the evidence for human exposure to harmful microorganisms from indoor air and surfaces. Published information about these contaminants, as well as measures to control them, including building design and energy conservation, were included in this review. Information on domestic dwellings, office environments, and other non-industrial settings was assessed to determine the reported prevalence, persistence, and transmission of microorganisms in these settings. Environmental factors that influence indoor microbiological colonization were also included. The evidence strongly indicates that ventilation is the primary factor for controlling indoor dampness, helping to mitigate indoor mold colonization and the accumulation of other indoor contaminants, including infectious microorganisms. Although modern building airtightness, including retrofits of older builds, contributes to thermal comfort and building energy efficiency, this may also limit a building’s ventilation capacity. This in turn can potentially allow biological pollutants to accumulate, increasing the likelihood of harmful exposures and ill-health effects for building occupants. Effective building design and maintenance, which promote appropriate levels of air exchange for indoor spaces, are therefore important for the control of indoor moisture and microbiological contamination. Full article

In Northeast China’s severe cold regions, increasingly airtight rural dwellings face a critical challenge: traditional biomass-fueled heating and cooking generate severe indoor particulate matter (PM) pollution, creating a sharp trade-off between maintaining thermal comfort and ensuring safe indoor air quality through ventilation. While multi-objective optimization is widely applied to urban buildings, its use to develop practical, behavior-based ventilation strategies for resource-constrained rural dwellings in this context represents a significant research gap. This study integrates field measurements of occupant behavior and environmental parameters from 192 households with a coupled thermal-PM_2.5 predictive model. The NSGA-II genetic algorithm was employed to perform a multi-objective optimization, balancing PM reduction against thermal comfort. The optimization reveals that short, high-intensity ventilation bursts are allowed. A typical optimized event can reduce post-cooking PM_2.5 concentrations to near-guideline levels while maintaining the indoor temperature within the residents’ adaptive comfort zone. This research provides the first evidence-based, region-specific natural ventilation guidelines for these dwellings. The findings offer a practical, no-cost strategy to mitigate health risks from indoor air pollution without significant energy penalties, providing a theoretical basis for future smart ventilation system design. Full article

Deep retrofits are one of the few pathways to decarbonize the existing building stock while simultaneously improving climate resilience. These retrofits improve insulation, airtightness, and mechanical equipment efficiency. NRCan’s Prefabricated Exterior Energy Retrofit (PEER) project developed prefabricated building envelope retrofit solutions to enable net-zero performance. The PEER process was demonstrated on two different pilot projects completed between 2017 and 2023. In 2024, in partnership with industry partners, NRCan developed new low-carbon retrofit panel designs and completed a pilot project to evaluate their performance and better understand resiliency and occupant comfort post-retrofit. The Low-Carbon Climate-Resilient (LCCR) Living Lab pilot retrofit was completed in 2024 in Ottawa, Canada, using low-carbon PEER panels. This paper outlines the design and construction for the pilot, including panel designs, the retrofitting process, and post-retrofit building and envelope commissioning. The retrofitting process included the design and installation of new prefabricated exterior retrofitted panels for the walls and the roof. These panels were insulated with cellulose, wood fibre, hemp, and chopped straw. During construction, blower door testing and infrared imaging were conducted to identify air leakage paths and thermal bridges in the enclosure. The retrofit envelope thermal resistance is RSI 7.0 walls, RSI 10.5 roof, and an RSI 3.5 floor with 0.80 W/m²·K U-factor high-gain windows. The measured normalized leakage area @10Pa was 0.074 cm²/m². The net carbon stored during retrofitting was over 1480 kg CO₂. Monitoring equipment was placed within the LCCR to enable the validation of hygrothermal models for heat, air, and moisture transport, and energy, comfort, and climate resilience models. Full article

The paper explores the application of heat pipes in thermal management for efficient heat dissipation, particularly in electrical equipment with high heat loads. Heat pipes are devices that transfer heat with high efficiency through the phase transition of the working medium (e.g., water, alcohol, ammonia) between the evaporator and the condenser, while they have no moving parts and are distinguished by their simplicity of construction. Different types of heat pipes—gravity, capillary, and closed loop (thermosiphon loop)—are suitable according to specific applications and requirements for the working position, temperature range, and condensate return transport. An example of an effective application is the removal of heat from the internal winding of a static energy converter transformer, where the use of a gravity heat pipe has enabled effective cooling even through epoxy insulation and kept the winding temperature below 80 °C. Other applications include the cooling of mounting plates, power transistors, and airtight cooling of electrical enclosures with the ability to dissipate lost thermal power in the order of 102 to 103 W. A significant advantage of heat pipes is also the ability to dust-tightly seal equipment and prevent the build-up of dirt, thereby increasing the reliability of the electronics. In the field of environmental technology, systems have been designed to reduce the radiant power of fireplace inserts by up to 40%, or to divert their heat output of up to about 3 kW into hot water storage tanks, thus optimising the use of the heat produced and preventing overheating of the living space. The use of nanoparticles in the working substances (e.g., Al₂O₃ in water) makes it possible to intensify the boiling process and thus increase the heat transfer intensity by up to 30% compared to pure water. The results of the presented research confirm the versatility and high efficiency of the use of heat pipes for modern cooling requirements in electronics and environmental engineering. Full article