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Using phase change materials (PCMs) is an efficient solution for reducing energy consumption in buildings. These materials have a large capacity for storing thermal energy, making them an appealing option for energy management purposes. Phase change materials have been successfully incorporated into various construction materials such as concrete, brick, or plaster. The primary objective of this review is to examine previous studies conducted on the application of PCMs in wood. The initial section presents an overview of the direct impregnation techniques utilized for wooden materials. This is followed by a discussion on the implementation of macroencapsulated PCMs in wooden structures that are typically present in residential buildings. In addition, the use of shape-stabilized PCM/wood composites, preventing potential leaks during the phase change transition, is explored. Finally, patents related to the use of PCMs in wood are described. Future challenges include the incorporation of PCMs into wood composites to improve their thermal properties. This literature review shows that there is a gap in knowledge regarding the utilization of phase change materials in wood-based panels such as oriented strandboards, fiberboards, and particleboards. This provides an opportunity for future research to improve the performance of the products manufactured by the wood-based panels industry. [ABSTRACT FROM AUTHOR]

Policymakers regularly implement stricter building energy-efficiency codes towards curtailing building energy use. Inevitably, super-insulating materials such as Vacuum Insulation Panels (VIPs) are essential to satisfy such codes. VIPs have been applied to buildings for over two decades now, with many lessons learned. Generally, the thermal conductivity values of VIPs often reported in the literature are the center-of-panel thermal conductivity (λcop) and effective thermal conductivity (λeff), factoring thermal bridges. However, there are other indexes, such as λ90/90 (declared value in the 90% percentile with a confidence of 90%) and λcop,90/90,aged (factoring aging), that increase consistently and reliably in the declared thermal conductivity value for VIPs. These indexes are scarcely computed and hardly reported. The main aim of this study was to examine the different declared thermal conductivity values of VIP-based guidelines, such as draft ISO DIS 16478, and evaluate their implications on annual building energy consumption. The main study constitutes four parts: (1) experimental evaluation of the thermal properties of pristine and aged VIP samples, (2) computation of thermal conductivity indexes, (3) numerical investigation of thermal conductivity indexes based on a reference building, and (4) related building energy implications. The mean λcop for 10 VIP samples was 0.0042 W/(mK) and increased to 0.0073 W/(mK) for  λ 90 / 90 , bridge, aged. Results show a significant bearing on building energy performance of as much as 2.1 GJ. [ABSTRACT FROM AUTHOR]

Phase change materials (PCMs) could be used in envelopes to moderate indoor temperature while hygroscopic materials could be used in envelopes to moderate indoor humidity. However, it remains unsolved whether these two materials are mixed to generate a better effect than single materials. Therefore, a transient model for coupled heat and moisture transfer through hygroscopic PCMs (HPCMs) was presented. The numerical cases of periodic boundary conditions and realistic weather conditions were conducted to investigate the heat and moisture transfer characteristics of three gypsum-based HPCMs containing different mass ratios of microencapsulated PCMs. Quantitative analyses were conducted to capture the effects of hygrothermal properties on heat and moisture transfer characteristics of HPCMs. The numerical results show that the mixing of PCMs and hygroscopic materials could generate a better temperature-humidity controlling effect than pure hygroscopic material, and the condensation risks inside the envelopes could also be reduced. Both the studied cases indicate that the HPCMs could be applied in building envelopes to passively moderate the indoor temperature and humidity simultaneously, reducing the building energy consumption and condensation risks inside the envelopes. The effects of hygroscopic and moisture transfer properties on temperature-control performance of HPCMs are relatively small, while the thermal properties play an important role in the improvement of temperature-humidity controlling performance of HPCMs with the increase of PCM concentration. [ABSTRACT FROM AUTHOR]

• We develop a slim double-skin window with a 20-mm-thick air cavity and single frame. • Heating and cooling energy use was analyzed through a 15-month testbed experiment. • The proposed window exhibits comparable energy efficiency to double-skin façades. • The life-cycle costs are 47% lower than those of double-skin façades. We developed a slim double-skin window (SDSW) with the aim of reducing building energy consumption for cooling and heating, thereby reducing the impact of buildings on climate change. The developed SDSW is a slim structure with an air cavity thickness of 20 mm, i.e., thinner than that of a traditional double-skin façade (DSF). We analyzed changes in the thermal properties and cooling and heating energy consumption of the SDSW as well as the effects of the thin air cavity on window performance. A testbed was constructed to analyze the seasonal temperature properties of the glass and the cooling and heating energy consumption. We also compared the long-term effects of the air cavity on the difference between outdoor and indoor glass surface temperatures under similar conditions for the SDSW and traditional DSF. The SDSW temperature was 3 °C lower than that of the traditional DSF, and the cooling and heating energy consumption dropped by 6.5%. Although the performance of the developed SDSW was comparable to that of traditional DSF, the life-cycle cost was reduced by 47%. [ABSTRACT FROM AUTHOR]