Search Results (90)

Under the dual challenges of global energy crisis and climate change, the building sector, as a major carbon emitter consuming 33% of global primary energy, has seen its energy efficiency optimization become a critical pathway towards achieving carbon neutrality goals. The Window-to-Wall Ratio (WWR), serving as a core parameter in building envelope design, directly influences building energy consumption, with its optimized design playing a decisive role in balancing natural daylighting, ventilation efficiency, and thermal comfort. This study focuses on the traditional One-Seal dwellings (Yikeyin) in Kunming, China, establishing a dynamic wind field-thermal environment coupled analysis framework to investigate the impact mechanism of window dimensions (WWR and aspect ratio) on indoor thermal comfort under natural wind conditions in transitional climate zones. Utilizing the Grasshopper platform integrated with Ladybug, Honeybee, and Butterfly plugins, we developed parametric models incorporating Kunming’s Energy Plus Weather meteorological data. EnergyPlus and OpenFOAM were employed, respectively, for building heat-moisture balance calculations and Computational Fluid Dynamic (CFD) simulations, with particular emphasis on analyzing the effects of varying WWR (0.05–0.20) on temperature-humidity, air velocity, and ventilation efficiency during typical winter and summer weeks. Key findings include, (1) in summer, the baseline scenario with WWR = 0.1 achieves a dynamic thermal-humidity balance (20.89–24.27 °C, 65.35–74.22%) through a “air-permeable but non-ventilative” strategy, though wing rooms show humidity-heat accumulation risks; increasing WWR to 0.15–0.2 enhances ventilation efficiency (2–3 times higher air changes) but causes a 4.5% humidity surge; (2) winter conditions with WWR ≥ 0.15 reduce wing room temperatures to 17.32 °C, approaching cold thresholds, while WWR = 0.05 mitigates heat loss but exacerbates humidity accumulation; (3) a symmetrical layout structurally constrains central ventilation, maintaining main halls air changes below one Air Change per Hour (ACH). The study proposes an optimized WWR range of 0.1–0.15 combined with asymmetric window opening strategies, providing quantitative guidance for validating the scientific value of vernacular architectural wisdom in low-energy design. Full article

To address the issues of poor thermal performance and high energy consumption in rural dwellings in cold regions of China, this study investigates multi-type energy-efficient retrofitting strategies for rural houses in the Hebei–Tianjin region. By utilizing a two-step cluster analysis method, 458 rural dwellings from 32 villages were classified based on household demographics, architectural features, and energy consumption patterns, identifying three typical categories: pre-1980s adobe dwellings, 1980s–1990s brick–wood structures, and post-1990s brick–concrete houses. Tailored sunspace design strategies were proposed through simulation: low-cost plastic film sunspaces for adobe dwellings (dynamic payback period: 2.8 years; net present value: CNY 2343), 10 mm hollow polycarbonate (PC) panels for brick–wood structures (cost–benefit ratio: 1.72), and high-efficiency broken bridge aluminum Low-e sunspaces for brick–concrete houses (annual natural gas savings: 345.24 m³). Economic analysis confirmed the feasibility of the selected strategies, with positive net present values and cost–benefit ratios exceeding 1. The findings demonstrate that classification-based retrofitting strategies effectively balance energy-saving benefits with economic costs, providing a scientific hierarchical implementation framework for rural residential energy efficiency improvements in cold regions. Full article

According to the China Building Energy Consumption and Carbon Emissions Research Report (2023), the construction industry accounts for 36.3% of total societal energy consumption, with residential buildings contributing significantly due to their extensive coverage and high operational frequency. Addressing energy efficiency and carbon reduction in this sector is critical for achieving national sustainability goals. This study proposes an optimization methodology for rural dwellings in Inner Mongolia, focusing on reducing energy demand while enhancing indoor thermal comfort and daylight performance. A parametric model was developed using Grasshopper, with energy consumption, thermal comfort (PPD), and Useful Daylight Illuminance (UDI) simulated through Ladybug and Honeybee tools. Key parameters analyzed include building morphology, envelope structures, and indoor thermal environments, followed by systematic optimization of building components. To refine multi-objective inputs, a specialized wall database was established, enabling categorization and dynamic visualization of material properties and construction methods. Comparative analysis demonstrated a 22.56% reduction in energy consumption, 19.26% decrease in occupant thermal dissatisfaction (PPD), and 25.44% improvement in UDI values post-optimization. The proposed framework provides a scientifically validated approach for improving energy efficiency and environmental adaptability in cold-climate rural architecture. Full article

In recent years, block-style commercial complexes have become a prominent form of commercial architecture in many Chinese cities. The thermal comfort of their outdoor spaces significantly influences people’s activities and the overall quality of these areas. This study explores the relationship between the morphological elements of outdoor spaces in such complexes and thermal comfort, using quantifiable methods to identify key control indicators. Enhancing thermal comfort is crucial for improving spatial quality, increasing dwell time, and boosting commercial vibrancy. Focusing on the hot summer and cold winter climate of Shanghai, this research analyzed two representative block-style commercial complexes. It employed computer simulations and sensory comfort surveys to demonstrate that block morphology significantly impacts outdoor thermal comfort. Three control variables—street density, number of street intersections, and street orientation—were selected to study their effects. Spatial prototypes were categorized, and their thermal comfort performance was evaluated using numerical simulations. Based on these findings, spatial morphology was iteratively optimized. This study concluded by proposing evaluation indicators for spatial morphology control elements to enhance outdoor thermal comfort. It also provided external spatial layout strategies for block-style commercial complexes in similar climates, offering architects and urban designers decision-making criteria to improve thermal comfort in outdoor spaces. This research contributes to creating more comfortable and vibrant urban environments. Full article

As buildings become more energy-efficient in cold climates, the unintended consequence of increased overheating risk during warmer seasons necessitates attention. In this context, there is an absence of research addressing the assessment of overheating risks in residential buildings in Ireland. This study assesses data from a sample of 1100 social housing units in Dublin, the majority of which have a Building Energy Rating (BER) of C, representing moderately insulated dwellings. Using indoor temperature data and outdoor climate reports for 2022, the research evaluates overheating risks based on both static and adaptive criteria in the living room zone of dwellings. The static methods used include the Chartered Institution of Building Services Engineers (CIBSE) Guide A and the Passivhaus Institute standard, while adaptive methods follow CIBSE TM59. The findings reveal discrepancies in overheating risk assessments: overall, 4% surpass thresholds under CIBSE Guide A. In contrast, 41% of dwellings exceeded overheating thresholds under the Passivhaus standard during the May to September 2022. Adaptive criteria, however, indicated minimal overheating instances, at 0.4%. These results highlight how different assessment methodologies influence overheating risk conclusions. The impact of this study is two-fold. First it further strengthens existing literature which questions the appropriateness of static methods. Secondly, it shows that the risk of overheating in moderately insulated buildings in this sample set is minimal. Full article

As China’s rural revitalization progresses, the green and sustainable development of traditional dwellings has gained significant attention. Traditional Qiang dwellings in western Sichuan, located in high-altitude cold regions, often feature thick walls and small windows, limiting air circulation. Buffer spaces play a key role in improving indoor air quality and reducing energy consumption through natural ventilation. This study explores traditional Qiang dwellings in western Sichuan through field research, architectural analysis, and numerical simulations. The study analyzes three buffer space types and compares natural ventilation in dwellings with and without buffer spaces. The results show better air circulation in buildings with buffer spaces. The simulation further shows that when the courtyard’s aspect ratio is 1.3 and the width-to-height ratio is 0.9, ventilation and air renewal rates are optimized. Based on this, the study proposes natural ventilation optimization strategies to reduce reliance on mechanical systems and improve energy efficiency. The study provides a scientific basis for low-carbon Qiang dwelling design and offers practical strategies for improving living environments, supporting sustainable rural development. Full article

Coal mining and combustion have the potential to increase exposure to radon, a form of radioactive gas recognized as one of the major contributors to lung cancer incidents. In South Africa, coal is used as the primary energy source for producing electricity and for heating, predominantly in informal settlements and township communities. Most of the existing coal-fired power plants are found in the Mpumalanga province. This paper presents long-term radon (²²²Rn) measurements in dwellings surrounding coal mining centres in the Mpumalanga province and evaluates their contributions to indoor radon exposures. The indoor radon measurements were conducted using solid-state nuclear track detectors and were performed during warm and cold seasons. It was found that the overall indoor radon activity concentrations ranged between 21 Bq/m³ and 145 Bq/m³, with a mean value of 40 Bq/m³. In all the measured dwellings, the levels were below the WHO reference level of 100 Bq/m³ and 300 Bq/m³ reference level recommended by the IAEA and ICRP, with the exception of one dwelling that was poorly ventilated. The results reveal that individuals residing in the surveyed homes are not exposed to radon levels higher than the WHO, ICRP, and IAEA reference levels. The main source influencing indoor radon activity concentrations was found to be primarily the concentration of uranium found in the geological formations in the area, with ventilation being an additional contributing factor of radon levels in dwellings. To maintain good air quality in homes, it is recommended that household occupants should keep their dwellings well ventilated to keep indoor radon levels as low as possible. Full article

This paper aims to investigate the indoor environmental conditions and energy use behaviours of older individuals in rural cold climates of China, with a specific focus on cooling practices during the summer months in the Shandong region. This study employs a mixed-method approach, combining quantitative indoor environmental monitoring with qualitative interviews and observations, to explore the relationship between environmental factors, household living conditions, and energy use patterns across five types of elderly households: three generations living together, older people living with grandchildren, older people living with children, older couples living together, and older people living alone. Data collection was conducted over five weeks during the summer of 2023 using HOBO UX100-003 data loggers, while external weather conditions were monitored by the China Meteorological Administration. Face-to-face interviews were conducted to gain deeper insights into daily cooling behaviours and energy use. The results reveal that cooling practices and indoor environmental conditions vary significantly among the different household types. Multigenerational households showed more complex energy use dynamics, with younger family members frequently operating high-energy appliances like air conditioners, while older individuals tended to rely on natural ventilation and electric fans to reduce energy costs. In contrast, older couples and solitary older individuals demonstrated more conservative cooling behaviours, often enduring higher indoor temperatures due to limited financial resources and a desire to minimize energy expenditures. Despite the high energy use intensity in some households, many homes failed to achieve comfortable indoor environments, particularly in dwellings with minimal insulation and older building materials. This study concludes that economic status, household structure, and building characteristics play crucial roles in shaping cooling behaviours and indoor comfort during the summer. Full article

Salmonid fishes provide an important indicator of climate change given their reliance on cold water. We evaluated temporal changes in the density of stream-dwelling brook trout (Salvelinus fontinalis) from surveys conducted over a 36-year period (1988–2023) by the Maryland Department of Natural Resources in Eastern North America. Nonparametric trend analyses revealed decreasing densities of adult fish (age 1+) in 19 sites (27%) and increases in 5 sites (7%). In contrast, juvenile fish (age 0) densities decreased in 4 sites (6%) and increased in 10 sites (14%). Declining adult brook trout trends were related to atmospheric warming rates during the study period, and this relationship was stronger than the effects of land use change or non-native brown trout. In contrast, juvenile fish trends generally increased with elevation but were not related to air temperature trends or land use change. Our analysis reveals significant changes in several brook trout populations over recent decades and implicates warming atmospheric conditions in population declines. Our findings also suggest the importance of temperature for adult survival rather than recruitment limitation in brook trout population dynamics. Full article

(1) Background: Many studies link food intake with clinical cognitive outcomes, but evidence for brain biomarkers, such as memory-related limbic white matter (WM) tracts, is limited. We examined the association between food groups, limbic WM tracts integrity, and memory performance in community-dwelling individuals. (2) Methods: We included 117 non-demented individuals (ALBION study). Verbal and visual episodic memory tests were administered, and a composite z-score was calculated. Diffusion tensor imaging tractography was applied for limbic WM tracts (fornix-FX, cingulum bundle-CB, uncinate fasciculus-UF, hippocampal perforant pathway zone-hPPZ). Food intake was evaluated through four 24-h recalls. We applied linear regression models adjusted for demographics and energy intake. (3) Results: We found significant associations between (a) higher low-to-moderate alcohol intake and higher FX fractional anisotropy (FA), (b) higher full-fat dairy intake and lower hPPZ FA, and (c) higher red meat and cold cuts intake and lower hPPZ FA. None of the food groups was associated with memory performance. (4) Conclusions: Despite non-significant associations between food groups and memory, possibly due to participants’ cognitive profile and/or compensatory mechanisms, the study documented a possible beneficial role of low-to-moderate alcohol and a harmful role of full-fat dairy and red meat and cold cuts on limbic WM tracts. Full article

The thermal performance of rural building envelopes is mostly non-standardized in Northern China, resulting in significant heat loss. In this study, we take, as an example, the central area of Liaoning province, with the objective of proposing some low-cost and energy-efficient solutions. Through our investigations, we found that heating energy consumption was reduced by 20% and construction costs increased by less than CNY 8000 (USD 1108), which can be accepted by rural residents. In order to achieve this target, the NSGA-II algorithm integrated with Rhino + Grasshopper and EnergyPlus simulation kernel was used to establish a thermal performance optimization model for the heat transfer of rural building envelopes in this severe cold region. Among the above-calculated Pareto optimal solutions, the recommended thickness of insulation layers for room floors, roofs, and external walls was about 70 mm, 50 mm, and 40 mm, respectively. Furthermore, we tried to reduce the window-to-wall ratio as much as possible. Finally, based on both the lower building renovation cost and energy-saving rate, three technical solutions from which rural residents could select, according to their specific needs, are put forward. Full article

Addressing the thermal comfort of the elderly is a pressing concern amidst the escalating aging population in rural China. This study presents a comprehensive assessment of the thermal comfort within traditional and self-built dwellings in the Guanzhong region. Utilizing a mixed-methods approach encompassing both on-site measurements and questionnaire surveys, with a novel approach of segmenting the elderly population into three distinct age groups. The findings indicate that: (1) An average clothing thermal resistance of 1.83 clo among the elderly, which was found to be relatively higher when compared to other areas and positively correlated with age; (2) A thermal neutral temperature of 8.46 °C for traditional dwellings and 10.53 °C for self-built dwellings, both of which were lower than anticipated, indicating a discrepancy between current living conditions and elderly residents’ thermal expectations; (3) A positive correlation between age and the preferred neutral temperature, with the elderly showing a preference for warmer indoor environments. Additionally, we propose targeted strategies to enhance the thermal comfort of the elderly across different age groups and dwelling types. This study refines the thermal comfort evaluation system for the elderly in China’s cold climate regions, offering theoretical insights and practical guidance for the renovation of rural dwellings and the improvement of elderly living standards in the Guanzhong area. Full article

With the background of rural revitalization, the urgent demand for energy conservation and improved living quality arises alongside the issues of high energy consumption and low comfort in residential buildings. Located in a region with a hot summer and cold winter climate, Hanzhong faces significant energy consumption for heating and cooling throughout the year, considering both winter insulation and summer heat insulation. Based on the energy consumption simulation and analysis of folk dwellings in Hanzhong, this paper employs a single-objective optimization method to explore the optimization of building envelope structures, including the window-to-wall ratio, bay width, number of floors, orientation, and floor height. Additionally, it investigates building layout, spatial organization, regional design methods, and energy acquisition. Through energy consumption simulation and validation of thermal comfort evaluation index PMV-PPD, design strategies such as building scale, layout organization, indoor and outdoor buffer space design, and building material selection are proposed to effectively improve indoor thermal comfort during the winter and summer seasons. This research provides insights and references for the low-carbon design and optimization of residential buildings. Full article

The ice stored in caves is a widespread yet neglected cryospheric component. The cold-adapted biodiversity of ice caves has received very little attention from research, despite the potential abundance of endemic troglobiotic and cryophilic species and their consequent sensitivity to the changing climate. In this study, we investigated the invertebrate diversity of two ice caves in Northeastern Italy (Bus delle Taccole and Caverna del Sieson, Veneto Region). During 2022 and 2023, we sampled, using pitfall traps, the invertebrates dwelling at different locations in each cave: the shaft base, an intermediate hall, and the cave bottom. At each cave location, we also collected ice samples, on which we measured the stable isotopes of oxygen and hydrogen (δ¹⁸O, δ²H), and monitored the air temperature with data-loggers. The two caves had different invertebrate communities, both dominated by a combination of troglobiotic and cryophilic taxa. Despite a low taxonomic richness, which was higher at Taccole (15 taxa) than at Sieson (11 taxa), both caves hosted rare/endemic species, four of which are not described yet. At each cave, the ice water isotopic signatures differed among cave locations, suggesting the ice had formed under different climatic conditions, and/or resulted from different frequencies of thawing/freezing events. The occurrence of summer melt at both caves suggests that these unique ecosystems will quickly disappear, along with their specialized and unique biodiversity. Full article

A large number of people in China still live in rural villages. The indoor environment of these rural dwellings directly affects the quality of life of the occupants. Nevertheless, constrained by the quality of dwelling construction, rural buildings have poorer indoor environments and, at the same time, have a higher operating energy consumption. However, inadequate attention has been given to the summer thermal environment in cold regions. This work has been carried out around the thermal environment of rural residences in cold regions during summer. Field measurements, questionnaires, and data analysis were used in this study. We recorded the indoor and outdoor thermal environment parameters on a typical summer day in the Linyi rural area. Moreover, the subjective sensations and thermal adaptive behaviors of the participants were recorded in detail with a questionnaire. Linear regression showed that the neutral temperature for residents in summer was 27.52 °C, with acceptable temperatures ranging from 25.14 °C to 29.9 °C. Age and gender differences were found to affect the occupants’ sensation of thermal comfort and humidity, as well as their thermal adaptive behavior. In addition, a thermal adaptive model has been constructed in the study, which will further enrich the thermal adaptive investigation and provide a scientifically sound reference for the renovation and development of the local rural areas. Full article