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The European Climate Law mandates a 55% reduction in CO2 emissions by 2030, intending to achieve climate neutrality by 2050. To meet these targets, there is a strong focus on reducing energy consumption in buildings, particularly for heating and cooling, which are the primary drivers of energy use and greenhouse gas emissions. As a result, the demand for energy-efficient and sustainable buildings is increasing, and thermal insulation plays a crucial role in minimizing energy consumption for both winter heating and summer cooling. This review explores the historical development of thermal insulation materials, beginning with natural options such as straw, wool, and clay, progressing to materials like cork, asbestos, and mineral wool, and culminating in synthetic insulators such as fiberglass and polystyrene. The review also examines innovative materials like polyurethane foam, vacuum insulation panels, and cement foams enhanced with phase change materials. Additionally, it highlights the renewed interest in environmentally friendly materials like cellulose, hemp, and sheep wool. The current challenges in developing sustainable, high-performance building solutions are discussed, including the implementation of the 6R principles for insulating materials. Finally, the review not only traces the historical evolution of insulation materials but also provides various classifications and summarizes emerging aspects in the field. [ABSTRACT FROM AUTHOR]

Thermal energy storage devices are gaining importance and momentum in the building space cooling and renewable energy applications. Retaining the stored energy for long hours through proper insulation is crucial in achieving economic benefits. In the present research, a novel composite material (FRP) is introduced for the development of cool storage tank along with two different methods of insulation (nitrile rubber foam insulation and vacuum insulation) to assess the performance of cool energy retention. The results show that the effect of vacuum insulation is lower compared with nitrile rubber foam insulation. This is due to the low specific heat capacity of the FRP material compared with air that increases the surface temperature of the tank than the ambient air during the day time in the case of vacuum insulation. Hence the study concludes that the additional layer of insulation material with high specific heat capacity than the ambient air to be added on the surface to avoid the overheating of the wall surface. The results are useful in designing the insulation for thermal storage tanks and managing the heat loss. [ABSTRACT FROM AUTHOR]

This article presents the author's methodology for testing selected parameters of a low-current vacuum arc, implemented using an innovative test stand based on a vacuum discharge chamber with a contact system mounted inside. In order to verify the validity of the adopted research methodology, as well as the correctness of the operation of the developed laboratory bench, measurements and calculations were made, among other things, of the energy and burning time of the vacuum arc, depending on selected factors, such as pressure and the delay time of the contact opening, calculated from the "passage through zero" of the sinusoid of the current flowing through the system. The tests were performed at 230 V and a current of 5 A for two pressure values: p1 = 1.00 × 105 Pa (atmospheric pressure) and p2 = 4.00 × 10−3 Pa (high vacuum environment). It was found that the vacuum insulation technique allows a significant reduction in the value of the arc energy and the burning time of the arc. It was also observed that in the case of a high vacuum environment, the ignition of the vacuum arc occurs after a time equal to about 3 ms from the "passage through zero" of the current flowing through the system. Below this value, the phenomenon did not occur. The results obtained provide an opportunity for the design and manufacturing of vacuum switchgear, where there is the prospect of reducing the negative effects associated with the arc burning process in the contact gap. [ABSTRACT FROM AUTHOR]

The oxygen content of M2 high-speed steel has not been intentionally controlled in industrial production through secondary refinement in vacuum furnaces. However, a lower oxygen content has a significant effect on the cleanliness, toughness, and addition of rare-earth elements to M2 high-speed steel. The changes in total oxygen content controlled by vacuum carbon deoxidation (VCD) treatment and inclusion evolution were investigated in M2 high-speed steel to understand the effects of carbon on dissolved oxygen and oxides in the carbon–oxygen (C-O) reaction process. Furthermore, the microstructure and properties of M2 high-speed steel caused by vacuum insulation and the role of reducing oxygen content in rare-earth alloying were briefly demonstrated. The results showed that the [O%] decreased from 30 ppm to 3 ppm in a vacuum at holding times above 25 min through the C-O reaction, leading to an inclusion reduction of approximately 70%. In the case of [O%] = 3 ppm in M2 high-speed steel, the addition of rare-earth elements has a greater effect on the inclusion characteristics. Lowering the oxygen content of M2 high-speed steel improves cleanliness and plays a significant role in rare-earth alloying. [ABSTRACT FROM AUTHOR]

The vacuum switch uses vacuum as the insulation and arc-extinguishing medium. It is the core equipment in high-voltage transmission and distribution power systems. Online detection of the vacuum level for vacuum switches is an international challenge that has not been effectively addressed for over 70 years. In a previous work, our team first proposed an online detection method for the vacuum level for vacuum switches based on laser-induced plasma (LIP), which holds the potential for achieving safe and reliable vacuum level detection. However, the accuracy of vacuum level detection based on a single variable is low and has difficulty in meeting the requirements of high-voltage transmission power systems. Considering the practical engineering application, where inspection personnel only need to know the order of magnitude of the vacuum level to assess the reliability of the vacuum switch, this study proposes a vacuum level prediction model based on the fusion of laser-induced plasma images and spectra. The proposed model comprises two modules: the Image module and Spectra module. The Image module fuses plasma and spectral images to extract features while the Spectra module extracts features from 1D spectral data. Ultimately, features from both images and 1D spectral data are combined for the final air pressure prediction. Experimental results revealed that the fusion of images and spectra improved the macro-precision (MacP) of air pressure prediction, achieving an accuracy of 96.83%. In comparison to utilizing only images or solely 1D spectral data for air pressure prediction, the MacP was increased by approximately 1.41% and 6.83%, respectively. Compared to other baseline models, this model has superior predictive performance. These findings underscore the effectiveness of the proposed air pressure prediction model that combines images and spectral results. This study establishes a foundation for the implementation of the proposed method for the online detection of the vacuum level based on laser-induced plasma in vacuum switches. [ABSTRACT FROM AUTHOR]

In light of escalating global energy demands and the imperative to reduce greenhouse gas emissions, the efficient transportation of liquefied natural gas (LNG) has become increasingly critical. As the evaporation of LNG from storage tanks represents a significant energy loss, improving tank insulation is crucial to optimize storage efficiency. This paper conducts a structural assessment of a smaller-sized Type C independent tank made of AISI 304L steel and examines the impact of two insulation techniques—vacuum and perlite—on their heat, structural, and fatigue behavior. Utilizing the finite element method (FEM), this study performs a heat transfer analysis followed by a structural analysis under combined loads in accordance with the International Gas Carrier (IGC) code. The subsequent fatigue analysis follows IGC procedures and is performed using third-party software. This article presents a detailed analysis of the heat transfer throughout the entire LNG tank and the stress levels under various combined load scenarios while providing insights into the critical stress points and the areas with the lowest fatigue life. Finally, this study confirms the viability of using both novel materials, perlite as an insulation material and Durolight for the tank support, because they meet the required limits. [ABSTRACT FROM AUTHOR]

Prefabricated temporary buildings are a promising solution for post-disaster scenarios for their modularity, sustainability and transportation advantages. However, their low thermal mass building envelope shows a fast response to heat flux excitations. This leads to the risk of not meeting the occupant comfort and HVAC energy-saving requirements. The literature shows different measures implementable in opaque surfaces, like vacuum insulation panels (VIPs), phase change materials (PCMs) and switchable coatings, and in transparent surfaces (switchable glazing) to mitigate thermal issues, like overheating, while preserving the limited available internal space. This paper investigates the energy and overheating performance of the mentioned interventions by using building performance simulation tools to assess their effectiveness. The optimization also looks at the transportation flexibility of each intervention to better support the decision maker for manufacturing innovative temporary units. The most energy-efficient measures turn to be VIPs as a better energy solution for winter and PCMs as a better thermal comfort solution for summer. [ABSTRACT FROM AUTHOR]

In order to store hydrogen in a liquid state at −253 °C, a double-structured tank trailer with inner and outer vessels is essential for maintaining insulation through a vacuum. While the smaller support of the inner vessel reduces heat loss, it raises concerns regarding its susceptibility to external factors like driving conditions. This study focuses on ensuring the safety of the tank trailer through design and analysis. Inner vessel thickness was determined using the membrane stress theory, verified per KGS guidelines. Structural safety of the 2.5-ton trailer was assessed following ASME Sec. VIII Div. 2 guidelines, simulating full hydrogen charge and adhering to CGA-H3. ASME BPVC XII specifications were applied, and a redesign mitigated stress concentration issues considering driving conditions. Following these steps, successful design and safety verification of the 2.5-ton trailer were achieved. [ABSTRACT FROM AUTHOR]

To achieve full-spectrum utilization of solar energy, photo-thermal synergistic catalysis for hydrogen production provided an efficient route. However, most of the studies only focused on how to realize the conversion of solar energy to thermal energy, and neglected the dissipation of thermal energy to environment. Here, we designed a device with vacuum insulation layer (DVIL), which can achieve heat transfer optimization to accelerate photocatalytic hydrogen evolution. Compared to conventional device which is in contact with ambient air directly (DCAD), DVIL exhibited faster heating response, and the final equilibrium temperature was raised by ∼20 °C, leading to enhancement of 47.3% and 28.7% on the hydrogen production rate from organic and inorganic reaction system, respectively. Further analysis on the heat transfer process proved that the vacuum layer serves as a thermal resistance that blocks the direct convective heat transfer between the reaction system and ambient air. Such thermal management through simple device designing holds great potential toward practical solar-to-hydrogen conversion and can be extended to other fields of photothermal catalysis. [Display omitted] • A device with vacuum insulation layer (DVIL) is designed to optimize heat transfer. • DVIL exhibits faster photothermal response and higher balanced temperature. • H 2 production is increased by 47.3% and 28.7% for organic and inorganic system. • Thermal management in photocatalytic hydrogen production is demonstrated. [ABSTRACT FROM AUTHOR]

Reducing the heat leakage during liquid hydrogen storage (LH 2) has been a critical issue for the long-distance transportation and large-scale application of hydrogen. A composite thermal insulation structure for LH 2 tanks, which integrated the variable density composite multilayer insulation (FVD-MLI) and vapor-cooled shield (VCS) with para-to-ortho hydrogen conversion (P–O) catalysts, is used. Based on the "Layer by Layer" models, para-hydrogen equilibrium fractions with different VCS temperatures and P–O efficiency with different flow rates are combined. The thermal effects of P–O in VCS are considered. Experimental results prove the insulation performance calculation model's accuracy. The heat leakage and temperature profile after filling the P–O catalysts in single VCS and double VCSs are obtained. The optimal insulation positions of single VCS and double VCSs are determined, and the consequence of the vacuum level on the insulation performance is discussed in detail. Increasing the VCS number from single to double and adding P–O catalysts can effectively improve the LH 2 tank's insulation performance. Compared with the single VCS, the heat flux through LH 2 tanks with double VCSs is reduced by 25.6%. The heat leakages to the tanks can be further reduced by 5.08% and 7.45%, respectively, after adding P–O catalysts in single VCS and double VCSs. Moreover, the cooling effects of P–O shift the optimal position of VCS towards the cold boundary. The single VCS optimal position is moved from 58% of the insulation structure thickness to 50.6%. The optimal positions of double VCSs are moved from 38.9% to 75%–31.1% and 71.7%, respectively. It is found that adding P–O catalysts and increasing the VCS numbers can effectively increase the insulation effect regardless of the vacuum degree between the thermal insulation structure. However, considering the P–O efficiency, the insulation improvement effects after adding P–O catalysts decrease with interlayer vacuum deterioration. • Adding VCS with para-to-ortho hydrogen conversion in insulation structure. • P–H 2 equilibrium fractions and P–O efficiency are combined. • Heat fluxes can be decreased by 5.08% and 7.45% by adding P–O catalysts. [ABSTRACT FROM AUTHOR]

The article presents the results of laboratory measurements of Ud breakdown voltages in a high-voltage vacuum insulating system for different pressures, contact gaps, type of electrode contacts and type of residual gas inside the discharge chamber. First of all, the electrical strength of the discharge chamber with a contact system terminated with contact pads made of W 70Cu 30 and Cu 75Cr 25 material was compared for selected values of contact gaps. It was found that below a pressure of p = 3.0 x 10 -1 Pa the electrical strength reaches an approximately constant value for each of the set contact gaps d. Analytical relationships were determined to calculate this value for each of the contact pads used. Above a pressure of p = 3.0 x 10 -1 Pa, the measured values of Ud breakdown voltages decrease sharply. The values of breakdown voltages in the discharge chamber with residual gases in the form of air, argon, neon and helium were also determined for selected values of contact gaps d. Depending on the residual gases used, significant differences were noted in the values of pressure p at which the loss of insulating properties in the discharge chamber occurred. These values were 3.3 x 10 -1 Pa for argon, 4.1 x 10 -1 Pa for air, 6.4 x 10 -1 Pa for neon, and 2.55 x 10 0 Pa for helium, respectively.

The effort to create low-carbon societies is now more than just a need for a sustainable world. According to the sectoral energy analyses carried out to reduce world energy consumption figures and greenhouse gas emissions, buildings are one of the most striking potential measures within the net zero target of the International Energy Agency (IEA) by 2050. Low/zero carbon standards are developed in this regard, which basically propose low-emission design and operational performance for buildings. Rather than using conventional insulation materials and techniques, drastic measures like thermal superinsulation are required to meet these standards in buildings. Among thermal superinsulation materials, aerogel blankets (ABs) and vacuum insulation panels (VIPs) attract attention day after day owing to their very low thermal conductivity ranges. Despite the slim, lightweight, and highly thermally resistive features of building envelopes retrofitted with ABs and VIPs, there are still some challenges, such as thermal bridges, hot and cold spots, durability, and especially cost issues. The aforesaid challenges usually take place when a wrong decision is made to internal or external insulation. There are still numerous discrepancies in the pros and cons of internal and external thermal superinsulation retrofit. Therefore, this short communication deals with the said discussion through the in-situ performance findings of retrofitted buildings. [ABSTRACT FROM AUTHOR]

Copyright of SDU Journal of Engineering Sciences & Design / Mühendislik Bilimleri ve Tasarım Dergisi is the property of Journal of Engineering Sciences & Design and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Due to the increasing energy demand around the world, new concepts have emerged in order to reduce it in the building sector. In this context, double-skin facade systems have increasingly been used due to their effectiveness in reducing the heating load, cooling load, and primary energy demand of buildings. In this study, an office building located in the industrial zone in Kocaeli/Gebze was examined, and the effects of nano-technological materials to be added to the building and double-skin facade systems on the energy performance of the building were determined using DesignBuilder and EnergyPlus simulation programs. As a result; with the thermochromic glass and vacuum insulation panels used in the nano scenario, the heating load was reduced by 70% when compared with the base model. In the double skin scenario implemented on the east–west facade, heating load was decreased by almost 25% and cooling and primary energy demand were decreased by nearly 20% as compared to the base model. Whereas, an efficiency of 20% in heating load, 40% in cooling load and almost 30% in primary energy demand was observed in the nano double skin scenario when compared with the base model. [ABSTRACT FROM AUTHOR]

International standards for vacuum insulation panels (VIPs) include an accelerated test method and a minimum quality standard for evaluating their long-term thermal performance after 25 years. The accelerated test method consists of various tests according to the characteristics of the core material and requires six months (180 days) at minimum. Herein, we propose an accelerated method for determining the long-term thermal performance of fumed-silica VIPs by shortening the required time and simplifying the procedure. Highly accelerated conditions (80 °C and 70% Relative humidity (RH)) were set for the evaluation method, using the maximum temperature (80 °C) cited in international standards and compared with the accelerated test method under accelerated conditions (50 °C and 70% RH). The inner-pressure increase rate of the VIP samples after conditioning for approximately 70 days was similar to that after conditioning for 180 days under highly accelerated and accelerated conditions, respectively. In addition, the estimated long-term thermal conductivities of the fumed-silica VIP were derived as 0.0076 and 0.0054 W/m·K under highly accelerated and accelerated conditions, respectively. These accelerated methods can be used to produce fumed-silica VIPs with similar long-term thermal conductivities. Therefore, the accelerated test method for long-term thermal performance using the highly accelerated conditions can be evaluated using a test that involves conditioning the sample for approximately 70 days under 80 °C and 70% RH. [ABSTRACT FROM AUTHOR]

In this study, a procedure for analyzing the hydrogen content of used getter material is described based on mass spectrometry coupled to thermal gravimetry. It is shown that hydrogen masses per getter mass in the range of 2 – 15 mg/g can be quantified. At least three differently strong hydrogen binding situations are found with the thermal desorption program applied so far. Up to 450 °C only traces of hydrogen can be desorbed from the getter material with the applied method and up to 99% is released on heating up to 800 °C.

In the current evolving building construction sector, the use of cold‐formed steel frames (CSF) has gained popularity due to their fast, clean, and flexible constructability. On the other side, in terms of the energy efficiency of a building, the use of CSF has raised concerns due to their high thermal conductivity, especially in the case of external wall panels. Hence, it is crucial to examine the thermal performance of such wall configurations and find solutions to reduce heat loss through walls by lowering the thermal transmittance, which would ultimately enhance the energy efficiency of the buildings. Accordingly, this study focuses on analysing the thermal performance of external wall panels made of cold‐formed and thin‐walled steel‐lipped channel studs with plasterboard linings and vacuum insulation panels (VIP). 2D and 3D finite element models developed in ABAQUS were used to analyse the effect of using VIP, oriented strand board and plasterboard, and their positions on the thermal transmittance of the CSF walls. 70 numerical analyses were conducted on 35 wall configurations and the results obtained were checked against the U‐value requirements set by UK building standards. It was found that replacing oriented strand boards with plasterboards does not substantially affect the thermal transmittance of the wall. However, adopting VIP as an insulation material has shown a U‐value reduction of up to 77%. But again, the change in position of VIP in the wall cross section has no notable effect on the U‐value. [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]

Aerogel is currently known to be one of the ideal core materials for vacuum insulation panels. The thermal performance of aerogel is discussed in detail. Thermal performance of nan-aerogel is sharply affected by its nanostructure. The nanostructure model of aerogel was reframed by the random generation method (RGM). A developed Lattice Boltzmann method (LBM) for predicting the effective thermal conductivity (ETC) of nano-granular materials was proposed. The accuracy of the method was experimentally verified. The results revealed that the simulation results and experimental data were in excellent accordance, which indicated, the method could be introduced for predicting the ETC of granules. The effects of granule diameter, internal pressure and density on ETC were analyzed in detail. Additionally, it was readily possible for granular porous material with a small diameter to keep a low ETC under high pressure. The ETC of aerogel increases rapidly versus temperatures increasing, particularly at high temperatures. In addition, an optimal density value of about 120 kg/m3 was recommended for maintaining low thermal conductivity. It was also found that there existed an optimal doping content that can minimize the ETC of aerogel. [ABSTRACT FROM AUTHOR]

The article presents the results of laboratory measurements of Ud breakdown voltages in a high-voltage vacuum insulating system for different pressures, contact gaps, type of electrode contacts and type of residual gas inside the discharge chamber. First of all, the electrical strength of the discharge chamber with a contact system terminated with contact pads made of W70Cu30 and Cu75Cr25 material was compared for selected values of contact gaps. It was found that below a pressure of p = 3.0x10-1 Pa the electrical strength reaches an approximately constant value for each of the set contact gaps d. Analytical relationships were determined to calculate this value for each of the contact pads used. Above a pressure of p = 3.0 x 10-1 Pa, the measured values of Ud breakdown voltages decrease sharply. The values of breakdown voltages in the discharge chamber with residual gases in the form of air, argon, neon and helium were also determined for selected values of contact gaps d. Depending on the residual gases used, significant differences were noted in the values of pressure p at which the loss of insulating properties in the discharge chamber occurred. These values were 3.3 x 10-1 Pa for argon, 4.1 x 10-1 Pa for air, 6.4 x 10-1 Pa for neon, and 2.55 x 100 Pa for helium, respectively. [ABSTRACT FROM AUTHOR]

Vacuum Insulation Panels (VIPs) provide significant adiabatic performance for heat/cooling systems to reduce energy consumption. The application of fibrous porous material (FPM) as the ideal core of VIPs has gained global attention in recent decades. The microstructure and physical properties of FPMs, filled as novel VIPs' core material, and holding superior thermal performance, affected effective thermal conductivity (ETC) greatly. Aiming to deeply understand heat transfer mechanisms, a holistic simulation method that combined with a developed 3D FPM structure generation method and a D3Q15-Lattice Boltzmann method (LBM) is proposed to simulate the heat transfer in FPM and to illuminate the influence factors of ETC on the microstructure of FPM in a vacuum. The improved and modified mesoscopic 3D fibrous random micro-structure generation approach involved five structural parameters: generation probability of nucleus growth, fiber length, diameter, coincidence rate, and orientation angle. The calculation model of ETC is established, and the discrete velocity, distribution, evolution, and boundary conditions of D3Q15-LBM are invested in detail. The model is validated with influences of different microstructure parameters. It indicated that FPM with finer diameter, smaller average pore size, and bigger orientation angle easily gain the lower ETC in a vacuum. The ETC was also affected by the orientation angles of fibers. The more the heat transfer direction is inconsistent with the length direction of the fiber, the better the adiabatic performance is. The reliability of the model is verified by comparison, and this work is a reference to optimize the fibrous core of VIPs. [ABSTRACT FROM AUTHOR]

Copyright of Guangdong Architecture Civil Engineering is the property of Guangdong Architecture Civil Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Terrestrial radiative cooling is an intriguing way to mitigate the accelerating cooling demands in the residential and commercial sectors by offering zero‐energy cooling. However, the ultra‐white or mirror‐like appearance of radiative coolers can be visually sterile and raise safety issues when applied to building facades and vehicles en masse. To overcome the fundamental trade‐off between color diversity and cooling performance, a radiatively integrated, conductively insulated material system is proposed that exploits thermal non‐equilibrium between colorants and thermal emitters. This allows such radiative coolers to be cooled below the ambient temperature at all times of the day while exhibiting any desired exterior color including black without using vacuum insulation. This work experimentally demonstrates that even black coolers, absorbing 646 W m−2 of solar power under AM1.5 conditions, cool down to a maximum of 6.9 K (average of 3.5 K) below the ambient temperature during the daytime. These systems can potentially be used in outdoor applications, especially in commercial buildings and residential houses, where carbon‐free thermal management is in high demand but diversity of colors is also important for visual appeal and comfort. [ABSTRACT FROM AUTHOR]

Solar irradiation is a clean form of energy, and absorption cooling systems powered by solar energy allow for significant energy savings. In the future, the demand for renewable energy may be the most effective way to serve clean energy, especially in Iraq, which has an excellent geographical location. In this research work, the performances of solar collector with and without of preheater have been evaluated. When compared to flat plate collectors at temperatures above 80°C, glass evacuated tube solar collectors provide the combined effects of a highly selective surface coating and vacuum insulation of the absorber element, resulting in a high heat extraction efficiency. Firstly, the Evacuated Vacuum Tube Solar Collector (EVTSC) was tested through experimentation. Secondly, Computational Fluid Dynamics (CFD) approach has been involved in this EVTSC system and thereby the conductive, convective and radiation based heat transfers are computed. Additionally, all possible with inclusive preheater cases are computationally investigated, thereafter the comprehensive report is prepared though validated computational procedures. Finally, the maximum efficiency is observed to be 53% without using a preheater and 61.8% with the usage of the preheater. The increase in efficiency using the preheater is found to be 16.6%. [ABSTRACT FROM AUTHOR]

This study is devoted to the possibility of using advanced insulation materials, such as Vacuum Insulation Panels (VIP), in the insulation and reconstruction of buildings, in connection with the green elements that are installed on the facade in the case of the use of external thermal insulation composite systems (ETICS). The use of VIP as part of the insulation system will result in a significant reduction in the required thickness of the insulation layer. In turn, the reduced overall thickness of the system will allow for easier direct anchoring of the elements of the green facade through the insulating layer to the base of the structure. The research carried out proves that, by using VIP in the insulation system (with a VIP thickness of 30 mm in combination with 20 mm of extruded polystyrene XPS), the thermal insulation properties can be significantly improved and, thus, the thickness of the insulation system can be reduced to 1/3 of the thickness of conventional insulation (while achieving the same thermal resistance), thereby enabling the anchoring of green elements on the surface of such an insulation system. [ABSTRACT FROM AUTHOR]

Precast facades are one of the most popular technology solutions featuring high-quality implementation and installation. They consist of three layers, both the external and internal layers are concrete composite, where the core is a thermal insulation material. This study explores the thermal performance improvement of these locally manufactured panels and evaluates their effectiveness in supporting building sustainability and energy saving. The study is performed experimentally. Leca and Addipor aggregates were used as a replacement of mix aggregate to produce lightweight heat-insulating concrete. Compressive strength equals 15MPa were taken for both Leca and Addipor replacement ratio. The study simulates several sections of precast concrete panels using ANSYS. Proposed concrete models with traditional and innovative thermal insulation materials, which are Expanded Polystyrene Foam (EPS), Extruded Polystyrene Foam (XPS), Rigid polyurethane foam (PU) and Vacuum insulation panels (VIPs), were analyzed. In addition, a virtual room space was simulated thermally using the previous sections to perform thermal simulations, as rate of heat transfer and amount of energy savings. The use of polyurethane foam (PU) as a new thermal insulation material and vacuum insulation panels (VIP) as an innovative thermal insulation material helps to reduce energy consumption by a rate of 143% and 700% of conventional insulation materials (EPS), respectively. It achieves internal thermal comfort and supports building sustainability. [ABSTRACT FROM AUTHOR]

Most of today's buildings will still be in use in 2050 and upgrades should therefore contribute to reducing energy consumption and carbon footprint. This paper addresses a challenge for upgrading of basement exterior walls of single-family dwellings, where ordinary retrofit insulation can lead to the basement wall protruding from the existing outer wall. For some, this will be an aesthetic barrier for an energy upgrade (an "ugly" solution). Superinsulation may solve this challenge without compromising the energy performance. This study analyses energy, cost and carbon footprint, to identify under which conditions upgrading with vacuum insulation panels (VIP) can be a preferred solution. Three alternatives are analysed in a parametric model: ordinary upgrade with XPS (the aesthetically "ugly"), upgrade with VIP above ground and XPS below ground (the aesthetically "good"), and iii) no upgrade (the "bad", as it does not contribute to reducing energy consumption). Results show that using VIP and XPS to perform energy upgrade of a basement exterior wall may lead to an aesthetically more pleasing solution than with only XPS, but that it will lead to higher carbon footprint and higher costs. The least favourable option is to install a drainage system without doing an energy upgrade, which will have negative impact for energy use, carbon footprint and life cycle cost. [ABSTRACT FROM AUTHOR]

The choice of thermal insulation technology for existing building retrofit can be a complex multi-criteria decision-making (MCDM) problem characterized by multiple stakeholders with conflicting interests. The conflicting interests of the building owners and the policymakers could negatively influence the adoption of low-carbon energy retrofit measures by building possessors, slowing down the progress toward sustainable development. The investigation of this issue is, therefore, crucial to support more informed decisions and offer policymakers useful insights to develop future economic incentives for energy refurbishment of buildings. Most of the existing MCDM studies on the subject do not emphasize the differences among different stakeholders nor consider the outcomes' robustness. To overcome this gap, this paper integrates multi-stakeholder analyses and robustness assessments to provide broad-spectrum and reliable results. An innovative robust MCDM framework for building thermal insulation under conflicting stakeholder interests is proposed and tested on a real case study building (located in Southern Italy) using building dynamic energy simulation. Several alternatives of thermal insulation are evaluated under environmental, energy, and economic key performance indicators (KPIs). The Analytic Hierarchy Process is used to define criteria weights for conflicting decision-makers representing collectivity (policymakers) and private interests. TOPSIS, VIKOR, WASPAS, and MULTIMOORA methods are integrated to perform initial rankings of the alternatives. A rank similarity analysis is performed to evaluate the consensus between MCDM methods, and an ensemble ranking is obtained for each decision-maker using an approach based on the half-quadratic theory. A Confidence Index and a Trust Level are used to evaluate the agreement among the MCDM approaches, verifying the reliability of the final ensemble ranking. The robustness of the framework is attained by complying with well-established literature guidance. The hybrid MCDM analysis showed that porous materials like expanded clay and expanded perlite lead to better results under the KPIs investigated. The worst performances are attained by vacuum insulation panels and aerogel, mainly due to high values of embodied CO 2 emissions and long payback periods. Insights upon the performance of different thermal insulating alternatives are also highlighted by the study and a stakeholder comparative analysis demonstrates that global rankings obtained for the different decision-makers show some similarities, but also important deviations, and a full compromise solution is not achieved. • Framework for hybrid multi-criteria decision-making for building energy retrofit • Optimal thermal insulation solution is attained under 3 key performance indicators • The impact of conflicting stakeholder interests is assessed in the analysis • The robustness of the ensemble ranking is attained using half-quadratic theory • Expanded clay and expanded perlite lead to better overall performance results [ABSTRACT FROM AUTHOR]

The accuracy of vacuum-dependent models for predicting thermal performance of Multi-Layer Insulation (MLI) and other layered insulation systems is critical for the development of novel solutions in the aerospace and energy sectors, particularly long distance superconductors and cryogenic transfer lines. This paper presents a review of the current state of the art in cryogenic vacuum insulation systems and their associated modelling techniques and test methods. Current modelling techniques, namely the Lockheed and McIntosh MLI models, are compared to cryogenic, boil-off calorimeter test data for 3 types of MLI from the current literature. Both current models provide acceptable accuracy at high vacuum pressures but deviate from the test data when gas conduction becomes the dominant heat transfer mechanism (K n ≤ 1). Neither of the current models follow the characteristic S-curve observed by researchers during insulation tests. This paper presents the introduction of a novel modelling approach for layered insulation systems though changes to the current state of the art, specifically at soft (p v a c ≤ 7.5 × 10 5 mTorr) and medium vacuum (p v a c ≤ 7.5 × 10 2 mTorr) pressures, by substituting the gas conduction term in both equations with alternative terms based on the system Knudsen number (Kn) and molecule mean free path (l). This results in a stronger pressure dependence across the vacuum regime. Both modified models exhibited the characteristic S-curve with significantly reduced errors over the entire range. • A review of the state of the art in vacuum insulation materials and models. • Novel use of a gas conduction term with the Knudsen number (Kn) in standard MLI models. • Improved heat flux correlation over entire vacuum range 1 × 10 − 2 mTorr ≤ p v a c ≤ 7.5 × 10 5 mTorr. • Heat flux correlation within 0.1 decade when applied to experimental MLI datasets at p v a c ≥ 10 mTorr. • Model correlations highlight sensitivity to MLI layer density and layer separation. [ABSTRACT FROM AUTHOR]

To reduce energy consumption in buildings, this paper investigates the feasibility of using natural fibers as cost-effective, environmentally sustainable core materials for vacuum insulation panels (VIPs). First, a comprehensive experimental study was conducted for 10 potential natural fiber candidates. The thermal conductivities of the 10 natural fiber mats at various vacuum pressures were measured; their compression and morphology properties were quantified. In addition, an analytical model was used to explore the major factors that influence the thermal conductivity of natural fibers as a function of internal air pressure. Results show that recycled cotton, kapok, and bamboo fibers are ideal candidates for VIP core materials; at <0.05 Pa, their thermal conductivities varied between 2 and 4 mW/(m⋅K). Furthermore, for some fibers, thermal conductivity was inversely proportional to fiber density. For the selection of fiber materials for VIP cores, the ideal fiber candidate has a small fiber diameter and a low fiber mat density. Based on thermal measurements, even though the internal air pressure of 5 Pa was enough to attain the minimum thermal conductivity, obtaining internal air pressure below 5 Pa is recommended for prolonged service life, considering small leaks of VIP package barrier films and potential off-gassing from fibers. The simulation results predicting the effective thermal conductivities matched the experimental results well. These findings indicate that natural fiber–based VIPs have the potential to be a sustainable, inexpensive alternative to the current technologies in building insulation materials. [Display omitted] • Recycled cotton, kapok, and bamboo fiber are ideal VIP–core material alternatives. • The thermal conductivities of these ideal alternatives were 2–4 mW/(m⋅K). • Increasing the density reduced the thermal conductivity for some fibers. • A fiber mat with a small fiber diameter and a low density could be a VIP core. • The internal air pressure of VIPs should be less than 5 Pa for a long service life. [ABSTRACT FROM AUTHOR]

Kapok fibre has the advantage of low density, low porosity and low thermal conductivity, which make it an excellent substitute for fumed silica and environmentally-unfriendly synthetic polymers as core material of vacuum insulation panels (VIP). However, kapok fibre is hydrophobic, consequently, kapok fibre core materials made by conventional wet forming with weakly-bound fibres and large voids that shorten their service life. Lignin is a natural and sustainable material that has good hydrophilicity and small particle size to form nano-porous networks. Therefore, we herein present the incorporation of lignin in kapok fibre to generate a composite core material with hierarchical porous structure. Lignin functionalises the kapok fibre surface to make it hydrophilic and dispersible in water. Simultaneously, lignin enhances the mechanical properties and service life of core material by transforming its internal microstructure. The effective thermal conductivity of prepared VIP is below 6.00 mW/(m∙K), and after 28 days of accelerated ageing test without desiccant or getter, the effective thermal conductivity increases less than 5.00 mW/(m∙K). Interestingly, the addition of lignin also reduces radiative heat transfer in the VIP. So, lignin addition enables high-performance VIP to be produced. Moreover, as a natural material, kapok fibre is low-cost, environmentally-friendly, sustainable, and energy-efficient. [Display omitted] • The lignin/kapok fibres composite core materials VIP were designed and prepared. • The mechanism of lignin improving the dispersion of kapok fibre was studied. • The thermal conductivity of composite core VIP could reach below 6.00 mW/(m∙K). • The addition of lignin in the VIP prolongs the service life. [ABSTRACT FROM AUTHOR]

Vacuum insulation panels (VIPs) have a potential to be used for retrofitting thermal insulation to existing buildings from the viewpoint of low thermal conductivity, small thickness, and light weight. However, in order to realize vacuum insulation panels applicable to building thermal insulation, it is necessary to overcome the challenge of maintaining the low pressure at which high thermal insulation performance can be achieved for several decades. The authors propose double envelope VIPs to maintain this long-term high thermal insulation performance. The double envelope VIP is fabricated by creating a single envelope VIP, wrapping the VIP with core materials, and then inserting it into the envelope for vacuum sealing. By applying the double envelope VIPs, the pressure difference and the permeation of gas in the inner VIP can be drastically reduced, resulting in a longer VIP lifetime. In this paper, the gas permeabilities of the gas barrier envelopes are experimentally estimated. Then, the pressure ageing in the double envelope VIP is calculated. The inner pressure of double envelope VIP after 50 years is 5.4 Pa for the envelope of aluminium composite film, indicating that low pressure can be maintained long-term. Next, the authors carry out accelerated test, in which the double envelope VIPs are placed in a chamber at 80oC and removed every two weeks to measure the effective thermal conductivity. Even after 141 weeks, one sample with a getter agent on the inside and a desiccant agent on the outside indicates only 10.5 % decrease in the thermal resistance. From this result, the long-term high thermal insulation performance can be obtained by fabricating double envelope VIPs. • Double envelope VIPs that can drastically reduce the gas permeation in inner VIP are suggested. • The gas permeabilities of the gas barrier envelopes are evaluated to predict pressure in VIPs. • Low pressure can be maintained long-term in the inner VIP of a double envelope VIP. • Accelerated test shows that double envelope VIPs can improve long-term high thermal insulation performance. [ABSTRACT FROM AUTHOR]

Surface charging commonly appears on dielectrics in vacuum in the presence of electron bombardment, seriously aggravating the superficial withstand strength of assorted devices. Nonetheless, a pre-conditioning technique is introduced in this paper capitalizing on surface charges to play an opposite role, enhancing flashover strength and suppressing the multipactor which is frequently found over vacuum insulator. A theoretical study is first performed, incorporated with particle-in-cell simulation to show the critical condition for a single-surface multipactor to initiate. Therewith, it is proven that a negative charge accretion in cathode adjacency can prevent the multipactor from commencing with efficiency. Subsequently, an analytical model is constructed to expatiate multipactor expansion with pre-set surface charges getting involved, illustrating an upper bound of its propagation velocity, influenced by pre-conditioning. Corresponding experiments are also conducted to corroborate previous conclusions, presenting both a deflected electron trajectory and an improved flashover threshold. In the end, a brief discussion is given on a possible method to generate desired surface charge distribution in practical applications. [ABSTRACT FROM AUTHOR]

This study describes a new vacuum insulation system, consisting of a flexible vacuum membrane and a load-transferring insulation layer comprising polyurethane foam (PUF), for large-scale LH 2 storage tanks. The vacuum membrane has a novel corrugated geometry to accommodate in-plane displacements induced by the thermal contraction of the inner tank, whereas the PUF layer transfers the external pressure load acting on the outer membrane onto the inner tank. To demonstrate and validate the overall performance of the proposed vacuum insulation system during extreme cooling at − 253 °C , it is applied to a 12,500-m3-LH 2 tank of the "lattice pressure vessel" type. Geometrically non-linear elastic–plastic analysis results show that the vacuum membrane deforms elastically under normal operating conditions of 1 atm pressure and 3 mm/m contraction displacement. The membrane is capable of withstanding harsh conditions, where both the pressure and displacement loads increase significantly. • A new vacuum insulation system for large-scale LH 2 storage tanks is proposed. • Main components of the system are presented and their structural functions are defined. • Theoretical background of the flexible vacuum membrane is presented. • The proposed vacuum insulation system is applied to a 12,500-m3 LH 2 tank to validate the structural capability of the system. [ABSTRACT FROM AUTHOR]

Summary: Vacuum insulation panels (VIP) are usually manufactured using standardized manufacturing processes based on empirical values and in most cases with any fumed silica as the main component of the core material. However, not all applications have the same requirements in terms of thermal conductivity and service life. Therefore, it is useful to adapt the kind of core materials and their product specifications, such as particle size and porosity, to the different applications. Furthermore, in some applications cheaper core materials, like precipitated silica, would be a reasonable alternative. To replace the time‐consuming series of measurements for this purpose, this work offers comprehensive parameter studies to determine the optimum product properties of precipitated silica, fumed silica, silica gel, and glass spheres for use in the building sector, in transport boxes, as a superinsulation at atmospheric pressure, and as a switchable VIP. As a result, not only the preferred materials but also their porosities and particle sizes are presented. For atmospheric pressure and construction applications, fumed silica has to be preferred. For the transport sector and switchable VIPs as well as certain special applications, precipitated silica and silica gel may well be reasonable alternatives. [ABSTRACT FROM AUTHOR]

It is difficult to obtain the interlayer vacuum degree of the LNG (liquified natural gas) vacuum multi-layer insulation pipe at any position, especially for pipes that are in service. Thus, this paper proposes a method for measuring interlayer vacuum degree of the vacuum multi-layer insulation pipe by temperatures. A vacuum multi-layer insulation pipe model was built to find the temperature parameters, and a field investigation and experiments with a test bench were carried out to verify the simulation results. The experimental results show that the simulation results have a good reference value for actual measurement. This method for measuring the interlayer vacuum degree will play an important role in the popularization of vacuum multilayer insulation pipes. [ABSTRACT FROM AUTHOR]

Using thermal insulation materials to reduce energy loss in buildings is a key action. For reducing the building's energy use, firstly, the internal unheated spaces (attics, cellars) should be insulated, followed by the insulation of the external walls, and changing the doors and windows. Finally, the building can be completed with the renovation/maintenance of its service systems. Newly designed and constructed buildings are subject to increasingly strict regulations, which highlight the minimization and elimination of wasteful energy use and the resulting emissions of harmful substances. Therefore, the use of thermal insulation is the first step in making buildings more energy efficient. In this editorial, seven articles covering thermal insulation possibilities and topics are highlighted. This paper reflected on the use of thermal insulations both for internal and external applications. This editorial also promotes the use of super insulation materials such as aerogels and vacuum insulation panels; furthermore, the possible applications of bio-based insulations are also endorsed. In this paper, the sound insulation capabilities of some materials are also emphasized, and they will be presented from the point of view of cost. [ABSTRACT FROM AUTHOR]

One of the important stages in the creation of the scientific and technical foundations for the calculation, design and manufacturing technology of the lowest heat-conductivity thermal protection from screen-vacuum thermal insulation (SVTI) is the development of a process for achieving the optimal vacuum P0 ≤ 10−3 Pa in the SVTI layers, since at this pressure, thermal conductivity (λeff) through the SVTI is carried out only due to the radiant (λrad) and contact-conductive (λk,k) components. It is proposed to obtain such a pressure in thermal insulation by using cushioning material in it, which was previously degassed in a separate vacuum chamber at 370−380 K for 12 h in order to remove water molecules from its structure and then replace them with nitrogen molecules. These molecules have 3−4 times less heat of adsorption; therefore they are pumped out faster. As a result, it becomes possible to accelerate (by ∼20 h) to achieve optimal vacuum in thermal insulation, as well as 11% lower effective thermal conductivity [equal to (14.1−14.3)⋅10−5 W/(m⋅K)]. The analysis carried out (according to the developed methodology) showed that the achieved optimal effective thermal conductivity of thermal insulation in a cryocontainers is determined by 33% of radiant thermal conductivity [4.7⋅10−5 W/(m⋅K)] and 67% of the contact-conductive component [9.4⋅10−5 W/(m⋅K)]. [ABSTRACT FROM AUTHOR]

The improvement of energy efficiency in buildings is one of the most important factors of the energy policy of Turkey owing to its energy import, especially of natural gas. Çorum city, one of the colder cities of Turkey that uses a high amount of natural gas as fuel for heating, was selected to demonstrate the reduction in energy loss and carbon dioxide emissions of buildings and to contribute to the insulation sector in the Çorum industry. Therefore, two different methods, namely, the Turkish standard 825 and heating degree‐days, are applied in cost‐optimal methodology, using four types of traditional insulation materials, namely, standard expanded polystyrene, neopor (graphite‐added expanded polystyrene), extruded polystyrene, and stone wool, and two state‐of‐the‐art insulation materials, aerogel and vacuum insulation panels in two types of reference buildings comprising hollow brick and pumice stone walls. As a consequence of application of the Turkish standard 825 and heating degree‐days methods in the cost optimal methodology of the European Energy Performance of Buildings Directive with the utilization of the optimum insulation thicknesses of six types of insulation materials calculated from both the Turkish standard 825 and heating degree‐days methods at four different types of windows and one top side measure, a new methodology was developed. Results obtained from three methodologies are compared based on insulation materials and wall types. [ABSTRACT FROM AUTHOR]

The adoption of phase change materials (PCMs) is a promising solution for the improvement of building energy performances and indoor comfort, and the integration of geopolymer concrete (GPC) allows recycling materials and reducing the demand for raw materials in concrete production. Both materials contribute to reducing the carbon dioxide emission in the building lifecycle. In this frame, this paper proposes a complete numerical approach for selecting the optimal wall package made of GPC and PCMs in a Mediterranean climate. The first step of the method consists of a parametric analysis for evaluating the incidence on energy performance and thermal comfort of the main designing variables: insulation thickness, air cavity type and its thickness, and PCMs type. Then, assuming the discomfort hours as a limiting constraint, a multi-objective optimization is applied to a subset of solutions for determining the Pareto front solutions. The advantage of the proposed methodology is the combined evaluations of multiple variables with a simplicity in execution; for this reason, it is useful for other researchers aimed at studying innovative solutions. According to obtained results, the better exposure for the proposed wall package is the north or northeast one. The minimization of the cooling energy demand requires the adoption of two PCMs, on internal and external sides, with melting temperature of 26 °C. The optimization of yearly performance requires the adoption of the maximum insulation level on both sides and a not-ventilated air gap between the modules. The cooling and heating energy need can be reduced, respectively, by around −29% and −57%, compared to a reference configuration with vacuum insulation panels and thermal transmittance of 0.4 W/m2 K. [ABSTRACT FROM AUTHOR]

One of the charged-particle accelerators with relatively low energy and relatively high current is the vacuum-insulated tandem accelerator proposed for boron neutron capture therapy and planned for use in a number of other applications requiring a more remote location of the neutron-generating target from the accelerator. In this work, the phase portrait of the ion beam and its dependence on the ion beam current and the strength of the magnetic lens focusing the beam of negative hydrogen ions on the input of the accelerator are measured. It is shown that the modernization of the magnetic lens contributed to the reduction of the spherical aberration of the lens and improved the quality of the negative ion beam. It has been established that the ion beam emittance increases with increasing current, and the space charge affects the phase portrait of the ion beam in the low energy transport path. To compensate for the action of the space charge on the phase portrait of the proton beam, the strength of the magnetic lens is changed. The obtained experimental data indicate that the proton beam can be transported to the site of the planned location of the neutron-generating target without adding focusing elements. [ABSTRACT FROM AUTHOR]

Pull‐out load capacity of thin composite dowels as fasteners for reinforced concrete wall panels Increasing requirements for thermal insulation and the reduction of transmission heat losses in buildings lead to an increased demand for energy‐efficient insulation systems and technologies for the building envelope. In this paper, thin composite dowels are used to present novel fasteners for an efficient vacuum‐insulated wall element. This element consists of two concrete layers and a vacuum‐insulated core layer. The individual layers are coupled by means of thin composite dowels, which are used as fasteners for reinforced concrete wall panels. Tensile tests are performed to investigate the load‐deformation behaviour of thin puzzle‐shaped composite dowels and to highlight the influence of different parameters such as reinforcement, embedment depth and number of composite dowel bars. The experimental results are compared with an existing model from the literature for determining the tensile capacity of composite dowels and evaluated in terms of their suitability. Based on this, a modified model for describing the tensile load‐bearing capacity of thin composite dowel bars is presented and validated based on the test results. [ABSTRACT FROM AUTHOR]

The results presented in this article relate to the work conducted to verify the existence of anode-induced phenomena, predominantly anode vaporization and consequent prebreakdown (PBD) current enhancement due to the impact of positive ions and microparticles over a relatively larger area at the cathode (presumably ion-assisted field (I-F) emission like). The verification of this hypothesis is attempted using a three-electrode arrangement. One electrode is comprised of a needle insulated from and projecting through a plane electrode (collector) of 40-mm diameter. It was surmised that if the positive ion beam from the anode spot (due to electron beam impact) were to be macroscopically diffuse, at least the collector would gather a part of it. However, no currents could be detected in the collector circuit even at voltages close to breakdown. The needle currents continued to display the typical characteristics of PBD currents under alternating voltages. The needle currents depended on the spacing between the needle tip and the plane of the collector and the polytetrafluoroethylene (PTFE) insulation used to prevent emission from the immediate vicinity of the needle evaporated significantly. Typical broad-area electrode behavior displayed by needle currents indicated that I-F emission, if any, is limited to the needle itself, which is certainly broad compared to the positive ion beam. Dependence of the PBD currents and breakdown voltages on the melting point of the anode material lend support to such anode-triggered electrode phenomena. [ABSTRACT FROM AUTHOR]

A variety of mathematical models are available to estimate the thermal performance of buildings. Nevertheless, mathematical models predict the thermal performance of buildings that might differ from the actual performance. The hot box is a widely-used test apparatus to assess the actual thermal performance of various building envelope components (walls, roofs, windows) in the laboratory. This paper presents the process of designing, constructing, and calibrating a unique small-scale hot box apparatus. Despite its smaller metering area (1.0 m × 1.0 m), this apparatus met the key requirements (below ±0.25 °C fluctuations in chambers' air temperature, and below 2.0% variation from the point-to-point temperature in reference to the temperature difference across the specimen) as prescribed in the ASTM C1363 and ISO 8990 standards. The walls of this apparatus are uniquely constructed using vacuum insulation panels or VIPs. The efficient and novel use of VIPs and workmanship during the construction of the apparatus are demonstrated through the temperature stability within the chambers. The achieved range of temperature steadiness below ±0.05 °C and point-to-point temperature variation below 1.0% of the temperature difference across the specimen allow for this apparatus to be considered unique among the calibrated hot box categories reported in the literature. In addition, having an affordable, simple-to-operate, and high-accuracy facility offers a great opportunity for researchers and practitioners to investigate new ideas and solutions. The apparatus was calibrated using two extruded polystyrene foam (XPS) specimens with thicknesses of 2″ and 4″. The calibration exercise indicates small differences between results obtained numerically, theoretically, and experimentally (below 3.0%). Ultimately, the apparatus was employed to measure the thermal properties of a specimen representing a lightweight steel framing (LSF) wall system, which is commonly used in cold climates. The results obtained experimentally were then compared to the ones estimated numerically using a 3D finite element modelling tool. The difference between the results obtained by both methods was below 9.0%. [ABSTRACT FROM AUTHOR]