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With the increasing energy consumption in buildings, the proportion of energy consumption in public buildings continues to grow. As an essential component of public buildings, sports buildings are receiving more attention regarding energy-saving technologies. This paper aims to study the passive energy-saving design methods of small-and medium-sized sports halls in hot summer and cold winter regions, exploring how to reduce building energy consumption by improving the spatial design and thermal performance of the enclosure structures of sports halls. Taking the Wuhu County Sports Center as an example, this study uses computer simulation software to analyze the building’s wind environment and the thermal performance of its external walls and roof. The results show that the large volume of the sports hall significantly impacts the distribution of wind speed and pressure around it, and this impact decreases with height. The thermal simulation of the enclosure structures demonstrates that adding insulation layers to the interior and exterior of the walls and roof of the sports hall is an effective way to reduce energy consumption in both winter and summer. Additionally, wind environment simulations of different roof shapes reveal that flat roofs have the most significant blocking effect on wind and are prone to inducing strong vortices on the leeward side; concave arch roofs have the least blocking effect on airflow, and arch and wave-shaped roofs maintain lower vortex intensity on the leeward side. Hopefully, this study can provide significant references for the energy-saving design of future small- and medium-sized sports buildings.

Phase change materials (PCMs) are recognized as a promising passive energy retrofit technology for existing buildings, as they are applied to the internal and external surfaces of the building with less impact on the original structure. However, the effectiveness of PCMs varies from region to region. Taking the Central Plains of China as an example, this paper investigated the effect of phase change temperature and material thickness variation on the energy efficiency of PCM when it was arranged on 14 placements including furniture through EnergyPlus (E+). And further explored the applicability of coupling PCMs with natural ventilation (NV). The results showed that: for the Central Plains of China, PCMs arranged on the internal surface of building roofs were optimal, and the reduction rate of uncomfortable degree hours could reach 38%, 26%, 24% and 40% after integrating PCMs into the roof, floor, external wall and furniture. The uncomfortable degree hour reduction rate per unit mass of PCM was 0.052%/kg for the roof, and the value of furniture was very close to the external wall and floor, which achieved 0.033%/kg. In addition, the coupling of PCM with NV improved the energy efficiency of PCM by more than twice. [ABSTRACT FROM AUTHOR]

The energy consumption of rural residential buildings in China is increasing, and the integration of phase change materials (PCMs) has emerged as an effective strategy to mitigate building energy use and carbon emissions. Given China's diverse climate zones and the varying construction forms of rural self-built houses (RSHs), the efficacy of PCM applications varies significantly across regions. This study presents a comprehensive investigation into passive energy savings using PCMs in RSHs across various climate zones. We investigate the energy saving potential and thermal comfort effects of installing PCMs with varying phase change temperatures and thicknesses at different laying positions in representative buildings from each climate zone. The results indicate that the optimal phase change temperatures in different regions closely align with the outdoor average temperatures during the application season. When the optimal phase change temperatures and appropriate thicknesses of PCM are applied, cost-effective energy savings are consistently achieved in building roofing across regions, with the most significant effects observed in the Severe Cold region, where the uncomfortable degree hours reduction rate (φ UDH) exceeds 90 %. • Focus on energy saving effect of phase change materials in rural self-built houses. • A synthetic study of typical rural self-built houses in all climatic zones of China. • Obtain optimal phase change temperature, thickness and economical laying position. • Acquire the maximum energy saving in Severe Cold region which is over 90 % in summer. • No significant energy savings in winter in all climate zones. [ABSTRACT FROM AUTHOR]

The development of flexible self-luminous reversible thermochromic passive energy-saving composites (TPCMs) is self-challenge due to the defects of easy leakage, non-visibility, solid phase rigidity, and weak light absorption. So, the emerging TPCMs were cleverly constructed using wood aerogel as support skeleton and different mass ratios of natural latex/long afterglow components as flexible and self-luminescent matrix based on optimal binary fatty alcohol eutectic (C 14 C 20). Among them, C 14 C 20 R-TEW-1R and C 14 C 20 G-TEW-0.35 P stand out with suitable phase transition temperatures (28.8 °C and 29.7 °C), high latent heat values (100.5 J g−1 and 119.4 J g−1), and low supercooling (0.7 °C and 0 °C). Induced by phase change, they change from rigid to flexible, from red/green to milky white, and can absorb light to achieve self-luminescence in the dark (orange red and blue-green) and enhanced photothermal efficiency. Beyond the traditional thermal/light stability and excellent anti-leakage performance, TPCMs realizes the combination of temperature sensitivity/control and self-luminous, providing broad application prospects in home automation, passive energy-saving in buildings, luminescent response switches, and other fields. [Display omitted] • Flexible and bifunctional passive energy-saving wood-based aerogel composites were designed. • It realizes the combination of temperature sensitivity/control and self-luminous. • It can absorb light to achieve self-luminescence in dark to enhance photothermal efficiency. • It breaks through the defects of easy leakage, non-visibility, solid phase rigidity, and weak light absorption. [ABSTRACT FROM AUTHOR]

Double-skin green facades using deciduous climbing plants are easy-to-implement construction systems stated to be effective energy-saving tools for buildings during cooling periods. Although the leaf area index (LAI) has been identified as a key parameter for characterizing foliar density and, consequently, the green facade's potential as a passive tool for energy savings, a lack of knowledge still remains on this index's values and measurement methods. The present paper aims to characterize the annual LAI evolution of a Boston ivy double-screen green facade under Mediterranean continental climate (Csa), by using an original non-destructive methodology during two consecutive years. Moreover, the influence of the green facade's foliage density, characterized by LAI, on the external building wall temperatures and the energy consumption by season and orientation was addressed. From the results it can be noticed that LAI changed seasonally over the course of five periods with a related differentiated energy performance: early summer (LAI of 4.8; 54% savings for cooling), late summer (LAI of 4.4; 30% savings for cooling), autumn (LAI of 1.7; 5.4% increase for heating), winter (LAI of 0.9; 5.4% increase for heating), and spring (LAI of 3.6; 11.9% increase for heating). The increase of energy consumption during leaf-off stage was directly linked to woody material and remaining leaves. Two crucial effects were identified and characterized: firstly, the influence of facade orientation and, secondly, a slight "insulation effect" at night, with the green screen acting as a thermal barrier. • Seasonal influence of deciduous green facades on building energy consumption. • Leaf area index (LAI) is key for characterizing foliar density and shadow effect. • Innovative methodology for the continuous measurement of LAI on green facades. • LAI changed seasonally over the course of five periods under Csa climate. • Large energy savings for cooling and slightly increment for heating. [ABSTRACT FROM AUTHOR]