Search Results (865)

With the promotion of national fitness, the requirements for regulating indoor environments during non-competition periods are low and relatively flexible under the trend of composite sports buildings. To maximize the use of natural ventilation and lighting for energy savings, passive optimization design based on building ontology has emerged as an effective strategy. This paper focuses on the spatial prototype of large- and medium-sized gymnasiums, optimizing key geometric design parameters and envelope structure parameters that influence energy consumption. This optimization employs a combination of orthogonal experiments and performance simulations. This study identifies the degree to which each factor affects energy consumption in the competition hall and determines the optimal low-energy consumption gymnasium prototype. The results reveal that the skylight area ratio is the most significant factor impacting the energy consumption of large- and medium-sized gymnasiums. The optimized gymnasium prototype reduced energy consumption by 5.3%~50.9% compared to all experimental combinations. This study provides valuable references and insights for architects during the initial stages of designing sports buildings to achieve low energy consumption. Full article

This study proposes a new air treatment system that integrates dehumidification, cooling, and water recovery using a Horizontal Air–Ground Heat Exchanger (HAGHE) combined with Peltier cells. The airflow generated by a fan flows through an HAGHE until it meets a septum on which Peltier cells are placed, and then separates into two distinct streams that lap the two surfaces of the Peltier cells: one stream passes through the cold surfaces, undergoing both sensible and latent cooling with dehumidification; the other stream passes through the hot surfaces, increasing its temperature. The two treated air streams may then pass through a mixing chamber, where they are combined in the appropriate proportions to achieve the desired air supply conditions and ensure thermal comfort in the indoor environment. A Computational Fluid Dynamics (CFD) analysis was carried out to simulate the thermal interaction between the HAGHE and the surrounding soil. The simulation focused on a system installed under the subtropical climate conditions of Nairobi, Africa. The simulation results demonstrate that the HAGHE system is capable of reducing the air temperature by several degrees under typical summer conditions, with enhanced performance observed when the soil is moist. Condensation phenomena were triggered when the relative humidity of the inlet air exceeded 60%, contributing additional cooling through latent heat extraction. The proposed HAGHE–Peltier system can be easily powered by renewable energy sources and configured for stand-alone operation, making it particularly suitable for off-grid applications. Full article

Residential and agricultural buildings must prioritize environmental sustainability, employing locally sourced, bio/geologically sustainable materials, and reversible construction methods. Hence, adobe construction and earth-based building methods are experiencing a comeback. This article describes the hygrothermal performances of a real scale agricultural building prototype, in real field conditions, built and designed to be energy-efficient, environmentally friendly, and well-suited for the hot, dry climates typical of the Mediterranean region during summer. The building prototype is a small modular two room construction, one room based on wood (for control purpose) and the other one on raw earth. The experimental set up highlights the passive cooling and humidity regulation potential provided by raw earth and adobe brick technology in agricultural buildings used for fruit and vegetable storage. Such passive cooling alternatives in the Mediterranean climate could reduce the need for energy-intensive and environmentally impactful cold storage rooms. Full article

In wet subtropical environments, perennial groundcovers are common in horticultural plantations to protect the soil from erosion. However, there has been little investigation into whether seeding annual cover crops into the perennial groundcovers provides additional soil services including carbon and nutrient cycling in these systems. To investigate this, farmer participatory field trials were conducted in commercial avocado, macadamia, and coffee plantations in the wet Australian subtropics. Cover crops were direct-seeded into existing inter-row groundcovers in winter (cool season cover crops), and into the same plots the following summer (warm season cover crops). Inter-row biomass was quantified at the end of winter and summer in the control (no cover crop) and cover crops treatments. Soil carbon and nutrient cycling parameters including hot water extractable carbon, water soluble carbon, autoclavable citrate-extractable protein and soil enzyme activities were quantified every two months from early spring (September) 2021 to late autumn (May) 2022. Seeded cover crops produced 500 to 800 kg ha⁻¹ more total inter-row biomass over winter at the avocado coffee sites, and 3000 kg ha⁻¹ biomass in summer at the coffee site. However, they had no effect on biomass production in either season at the macadamia site. Soil functional parameters changed with season (i.e., time of sampling), with few significant effects of cover crop treatments on soil function parameters across the three sits. Growing a highly productive annual summer cover crop at the coffee site led to suppression and death of perennial groundcovers, exposing bare soil in the inter-row by 3 weeks after termination of the summer cover crop. Annual cover crops seeded into existing perennial groundcovers in tree crop systems had few significant impacts on soil biological function over the 12-month period, and their integration needs careful management to avoid investment losses and exacerbating the risk of soil erosion on sloping lands in the wet subtropics. Full article

Ulcerative colitis (UC) is a subtype of inflammatory bowel disease (IBD) that has been associated with overconsumption of calories and lipids, compared to the healthy population, and summer temperatures have been reported to be closely related to the prevalence of UC. To evaluate the effects of dietary and lifestyle factors on UC, a combination of 2.0% dextran sulfate sodium (DSS), a high-fat/high-sugar diet, and exposure to high temperature and humidity was used to construct mouse models of UC. Changes in body weight, disease activity index (DAI) scores, histopathological analysis, serum lipid levels, serum diamine oxidase (DAO), and D-Lactate (D-LA) levels, as well as the expression of inflammatory cytokines and tight junction proteins in colonic tissue, were all assessed to study the impacts of the high-fat/high-sugar diet and high-temperature/high-humidity exposure on the progression of UC. The symptoms observed in the UC mouse model induced by 2.0% DSS alone were similar to those seen in patients with UC, while the high-fat and high-sugar diet, along with humid and hot exposure, exacerbated DSS-induced UC in the mice. This included more severe histopathological damage to the colon tissue, increased expression of pro-inflammatory cytokines (IL-6, IL-17A, and IL-1β), and a more significantly compromised intestinal barrier, characterized by the destruction of ZO-1 and elevated levels of DAO and D-LA. Additionally, the high-fat/high-sugar diet and high-temperature/high-humidity exposure led to further disturbances in glucose and lipid metabolism in the mice, which were not observed in those treated with DSS alone. This study is the first to investigate the effects of a high-fat/high-sugar diet and high-temperature/high-humidity exposure on the progression of UC. Full article

As a densely populated area, college student dormitories consume a large amount of electricity every year to heat the domestic hot water used by students. Applying solar energy to hot water systems can effectively alleviate this situation. This paper first conducts a simulation of the hot water load and the calculation of the available area of the solar roof in a dormitory building of a certain university. Then, different solar-coupled air source heat pump systems were designed, and simulation models of the two systems were established. The thermal performance parameters and solar energy utilization of the two systems were discussed, and the energy efficiency, economy, and environmental protection of the two systems were analyzed. The results show that after coupling with the solar collector, the system operation time is shortened by 26.2%, the annual performance coefficient is 3.4, which is 0.8 higher than that of the original system, and the annual heating energy consumption is reduced by 24.4%. In contrast, the annual energy self-sufficiency rate of the photovoltaic coupled with air source heat pump system is 94.6%, achieving nearly zero energy consumption for heating. Full article

Driven by the global energy transition and China’s dual-carbon targets, Passive ultra-low-energy buildings are a key route for carbon reduction in the construction sector. This study addresses the high energy demand of office buildings and the limited suitability of current efficiency codes in the hot-summer/cold-winter, high-humidity zone of central and southern Anhui. Using multi-year climate records and energy-use surveys from five cities and one scenic area (2013–2024), we systematically investigate climate-adaptive passive-design strategies. Climate-Consultant simulations identify composite envelopes, external shading, and natural ventilation as the three most effective measures. Empirical evidence confirms that optimized envelope thermal properties significantly curb heating and cooling loads; a Huangshan office-building case validates the performance of the proposed passive measures, while analysis of a near-zero-energy demonstration project in Chuzhou yields a coordinated insulation-and-heat-rejection scheme. The results demonstrate that region-specific passive design can provide a comprehensive technical framework for ultra-low-energy buildings in transitional climates and thereby supporting China’s carbon-neutrality targets. Full article

Animal production generates gas emissions. It is imperative to reduce them as projections suggest that emissions will continue to increase with rising temperatures, alongside the intensification of agriculture to meet global food demand. Slurry acidification in-house can reduce these emissions. In this study, an acidification technology was installed in a pig-fattening barn to evaluate the influence of the addition of a mixture of organic acids, mainly lactic acid and glycolic acid, on NH₃ and GHG emissions. A total of 384 pigs were allocated to four experimental rooms, two with additive applied to the slurry pits by a spraying system and two as a control. In high-temperature conditions, the spraying system discharged additive over the slurry which, in contrast with other systems, was stored inside the rooms during the whole trial. The concentration of NH₃ and GHG, the temperature, and the air extraction rate were measured continuously. A significant reduction in the emissions of the gases evaluated was achieved. NH₃ emissions were reduced by 26.8%, CH₄ by 23.6%, N₂O by 25.0%, and CO₂ by 28.7%. The role of the dynamic spraying system is considered essential to prevent the acidification effect being reversed by the buffering effect of the slurry itself. Full article

Urban outdoor thermal comfort (OTC) has become an increasingly critical issue under the pressures of urbanization and climate change. Comparative analyses of urban blocks with distinct spatial morphologies are essential for identifying OTC issues and proposing targeted optimization strategies. However, existing studies predominantly rely on microclimate numerical simulations, while comparative assessments of OTC from the human thermal perception perspective remain limited. This study employs the thermal walk method, integrating microclimatic measurements with thermal perception questionnaires, to conduct on-site OTC investigations across three urban blocks with contrasting spatial morphologies—a business district (BD), a residential area (RA), and a historical neighborhood (HN)—in Beijing, a hot summer and cold winter climate city. The results reveal substantial OTC differences among the blocks. However, these differences demonstrated great seasonal and temporal variations. In summer, BD exhibited the best OTC (mTSV = 1.21), while HN performed the worst (mTSV = 1.72). In contrast, BD showed the poorest OTC in winter (mTSV = −1.57), significantly lower than HN (−1.11) and RA (−1.05). This discrepancy was caused by the unique morphology of different blocks. The sky view factor emerged as a more influential factor affecting OTC over building coverage ratio and building height, particularly in RA (r = 0.689, p < 0.01), but its impact varied by block, season, and sunlight conditions. North–South streets generally perform better OTC than East–West streets, being 0.26 units cooler in summer and 0.20 units warmer in winter on the TSV scale. The study highlights the importance of incorporating more applicable physical parameters to optimize OTC in complex urban contexts and offering theoretical support for designing climate adaptive urban spaces. Full article

The performance of solar thermal systems for space heating and domestic hot water (DHW) production depends on the tilt angle of solar collectors, which governs the amount and seasonal distribution of captured solar radiation. This study evaluates the impact of fixed collector tilt angles on the annual solar fraction (SF) of a solar heating system designed for a typical single-family house located in Kraków, Poland (50° N latitude). A numerical model based on the f-Chart method was employed to simulate system performance under varying collector areas, storage tank volumes, heat exchanger characteristics, and DHW proportions. The analysis revealed that although total annual irradiation decreases with increasing tilt angle, the SF reaches a maximum at a tilt angle of approximately 60°, which is about 10° higher than the local geographic latitude. This configuration offers a favorable balance between winter energy gain and summer overheating mitigation. The results align with empirical recommendations in the literature and offer practical guidance for optimizing fixed-tilt solar heating systems in temperate climates. Full article

This study evaluates the performance degradation of spray rigid polyurethane foam (RPUF) insulation on reservoir dam structures under multi-physics coupling conditions. Focusing on characteristic environmental exposures in Hot Summer and Cold Winter (HSCW) climate zones, accelerated aging tests simulating coupled temperature–humidity effects were conducted to comparatively analyze the thermal resistance and durability evolution between unprotected and encapsulated RPUF configurations. Scanning electron microscopy (SEM), infrared spectroscopy (IR), and other methods were used to characterize and analyze the structure of RPUF. Research has shown that in HSCW climate zones, the thermal conductivity of RPUF gradually increases with the number of degradation cycles, and the insulation performance decreases, mainly due to the damage of the pore structure caused by temperature aging and the combined effect of moisture absorption aging. In comparison, the RPUF after protection can effectively slow down the rate and degree of decline of its insulation performance. On this basis, a time-varying prediction model for the thermal conductivity of RPUF under long-term service in HSCW climate environments was fitted, providing a scientific basis for the durability evaluation of reservoir dam insulation. Full article

With the continual expansion of global urbanization and population growth, urban energy demands have intensified, and anthropogenic activities have precipitated profound shifts in the global climate. These climatic changes directly alter urban environmental conditions, which in turn exert indirect effects on human physiological function. Consequently, the comfort of outdoor community environments has emerged as a critical metric for assessing the quality of human habitation. Although existing studies have focused on improving singular environmental factors—such as wind or thermal comfort—they often lack an integrated, multi-factor coupling mechanism, and adaptive strategy systems tailored to hot-summer, cold-winter regions remain underdeveloped. This study examines the Minhe Community in Qian’an City to develop a performance evaluation framework for outdoor spaces grounded in subjective comfort and to close the loop from theoretical formulation to empirical validation via an interdisciplinary approach. We first synthesized 25 environmental factors across eight categories—including wind, thermal, and lighting parameters—and applied the Analytic Hierarchy Process (AHP) to establish factor weights, thereby constructing a comprehensive model that encompasses both physiological and psychological requirements. Field surveys, meteorological data collection, and ENVI-met (V5.1.1) microclimate simulations revealed pronounced issues in the community’s wind distribution, thermal comfort, and acoustic environment. In response, we proposed adaptive interventions—such as stratified vegetation design and permeable pavement installations—and validated their efficacy through further simulation. Post-optimization, the community’s overall comfort score increased from 4.64 to 5.62, corresponding to an efficiency improvement of 21.3%. The innovative contributions of this research are threefold: (1) transcending the limitations of single-factor analyses by establishing a multi-dimensional, coupled evaluation framework; (2) integrating AHP with ENVI-met simulation to realize a fully quantified “evaluation–simulation–optimization” workflow; and (3) proposing adaptive strategies with broad applicability for the retrofit of communities in hot-summer, cold-winter climates, thereby offering a practical technical pathway for urban microclimate enhancement. Full article

Iraq’s extreme summer temperatures pose critical challenges to pavement durability, as conventional asphalt mixtures often fail under prolonged thermal stress. This paper provides a comparative evaluation of the high-temperature performance of unmodified (40/50 penetration grade) and polymer-modified (PG 76-10) asphalt mixtures for the asphalt course layer. Marshall stability, flow, and stiffness were measured at elevated temperatures of 60 °C, 65 °C, 70 °C, and 75 °C after short-term (30 min) and extended (24 h) conditioning. Results show that while both mixtures experienced performance degradation as the temperature increased, the polymer-modified mixture consistently exhibited superior thermal resistance, retaining approximately 9% higher stability and 28% higher stiffness, and displaying 18% lower flow deformation at 75 °C compared to the unmodified mixture. Stability degradation rate (SDR), stiffness degradation rate (SiDR), and flow increase rate (FIR) analyses further confirmed the enhanced resilience of PG 76-10, showing nearly 39% lower FIR under thermal stress. Importantly, PG 76-10 maintained performance within specification thresholds under all tested conditions, unlike the conventional 40/50 mixture. These findings emphasize the necessity of adapting mix design standards to regional climatic realities and support the broader adoption of polymer-modified asphalt binders to enhance pavement service life in hot-climate regions like Iraq. Full article

In the context of global energy challenges, adaptive shading systems have emerged as pivotal components in building energy efficiency research. This study systematically evaluates critical performance factors influencing energy efficiency in adaptive shading systems for buildings located in hot summer and cold winter climate zones, with a focus on parametric optimization of shading panel configurations. Through field measurements, orthogonal experimental design, and numerical simulations, this investigation centers on the adaptive shading system of a nearly zero energy building (NZEB). Four critical parameters—shading panel width, panel-to-window clearance, window-to-wall ratio (WWR), and surface reflectance—were rigorously analyzed through orthogonal experimental methodology and DesignBuilder^® simulations. This study identifies WWR and shading panel reflectance as the key factors for optimizing adaptive shading systems. Among the scenarios evaluated, the highest energy efficiency was achieved with horizontal shading devices on the south façade, featuring a panel width of 500 mm, a minimum clearance of 150 mm, a WWR of 55%, and a surface reflectance of 0.4. Under this configuration, the annual energy consumption was reduced to 8312.37 kWh, corresponding to a 2.1% decrease (8.31 MWh) in total site energy consumption (TSEC). This research provides valuable insights for energy-efficient building design in hot summer and cold winter regions, and supports the broader adoption of adaptive shading systems. Full article

This article is devoted to the study of a 20 MW large-scale photovoltaic power plant (LS-PVPP), connected to the grid and located in Naàma, Algeria. The power plant is included in the National Program for the Development of Renewable Energies 2015–2030. Among the parameters analyzed in detail in this work, the performance ratio recorded an average value of 67.55%, the capacity factor had an average of 17.10%, the total losses had an average of 2.10 kWh/kWp/day, the system efficiency had an average of 4.10 kWh/kWp/day and an annual average of 9.84% of the efficiency. A linear regression equation with a coefficient of determination R² of 0.91 confirms the importance of irradiation impact in the region; less significant linearity for the effect of temperature with a coefficient of determination R² = 0.28 is recorded for production. A comparative study conducted with the Adrar plant (Algeria) with an extremely hot desert climate and the Saida plant (Algeria) with a semi-arid climate demonstrated that the efficiency of the Naàma station is equal to 91.22% of the efficiency of Adrar and 73.47% of the efficiency of Saida. Naàma is known for its semi-arid climate; it is very cold in winter and hot in summer, with sandstorms becoming more frequent due to climate change. PVsyst software (Version 7.4.8) is used to validate the results. Full article