scholarly journals Determining the Aging Performance of Vacuum Insulation Panels: Development of a Prediction Model

2021 ◽  
Author(s):  
Melissa Morlidge
Keyword(s):  
Service Life ◽  
Thermal Resistance ◽  
Accelerated Aging ◽  
Extended Period ◽  
Building Envelope ◽  
Core Material ◽  
Vacuum Insulation ◽  
Critical Components ◽  
Quality Material ◽  
Metallic Foils

Vacuum insulation panels (VIPs) are increasingly being explored in building applications. Typically used in industrial processes such as aerospace engineering, cryogenics and refrigerator manufacturing, VIPs have been proven to provide a higher thermal resistance per inch than typical building insulation materials. However, there is speculation on the performance of these panels over an extended period of time due to various factors which gradually cause a reduction in thermal resistance. The purpose of this research project is to identify these variables and how they alter VIP performance over the product’s service life. Based on a thorough literature review, the critical components were interpreted to develop a numerical model which can predict the future performance of VIPs as they age, based on initial material properties. This model is intended to benefit designers and researchers in the construction industry; in understanding the potential for vacuum insulation to contribute to building envelope design. The results of calculation proved to be complementary to experimental results provided by the NRC, (initial calculated conductivities ranged from 4.17x10 The highest calculated conductivity was attributed to the low quality metalized (MF) VIP with a final conductivity after accelerated aging of 5.29 x 10 Some observations included that there is little difference between aluminum and metallic foils in their initial conductivity; however the aluminum foils represented in this report outperformed the chosen metallic foils over time, as they provided smaller gas and water vapour transmission rates. The core material variables with the greatest impact on performance were density and porosity. Some of the simulated panels exceeded the conductivity limit before the end of their service life, while others did not. Therefore the conclusion for VIP performance overall cannot be confirmed, although the development of standards within the industry would ensure high quality material integration within building systems.

scholarly journals Determining the Aging Performance of Vacuum Insulation Panels: Development of a Prediction Model

2021 ◽  
Author(s):  
Melissa Morlidge
Keyword(s):  
Service Life ◽  
Thermal Resistance ◽  
Accelerated Aging ◽  
Extended Period ◽  
Building Envelope ◽  
Core Material ◽  
Vacuum Insulation ◽  
Critical Components ◽  
Quality Material ◽  
Metallic Foils

Vacuum insulation panels (VIPs) are increasingly being explored in building applications. Typically used in industrial processes such as aerospace engineering, cryogenics and refrigerator manufacturing, VIPs have been proven to provide a higher thermal resistance per inch than typical building insulation materials. However, there is speculation on the performance of these panels over an extended period of time due to various factors which gradually cause a reduction in thermal resistance. The purpose of this research project is to identify these variables and how they alter VIP performance over the product’s service life. Based on a thorough literature review, the critical components were interpreted to develop a numerical model which can predict the future performance of VIPs as they age, based on initial material properties. This model is intended to benefit designers and researchers in the construction industry; in understanding the potential for vacuum insulation to contribute to building envelope design. The results of calculation proved to be complementary to experimental results provided by the NRC, (initial calculated conductivities ranged from 4.17x10 The highest calculated conductivity was attributed to the low quality metalized (MF) VIP with a final conductivity after accelerated aging of 5.29 x 10 Some observations included that there is little difference between aluminum and metallic foils in their initial conductivity; however the aluminum foils represented in this report outperformed the chosen metallic foils over time, as they provided smaller gas and water vapour transmission rates. The core material variables with the greatest impact on performance were density and porosity. Some of the simulated panels exceeded the conductivity limit before the end of their service life, while others did not. Therefore the conclusion for VIP performance overall cannot be confirmed, although the development of standards within the industry would ensure high quality material integration within building systems.

scholarly journals Critical Review of Polymeric Building Envelope Materials: Degradation, Durability and Service Life Prediction

Buildings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 299
Author(s):  
Marzieh Riahinezhad ◽  
Madeleine Hallman ◽  
J-F. Masson
Keyword(s):  
Climate Change ◽  
Service Life ◽  
Critical Review ◽  
Life Prediction ◽  
Building Envelope ◽  
Service Life Prediction ◽  
Degradation Mechanisms ◽  
Material Component ◽  
Aging Conditions ◽  
Environmentally Sound

This paper provides a critical review of the degradation, durability and service life prediction (SLP) of polymeric building envelope materials (BEMs), namely, claddings, air/vapour barriers, insulations, sealants, gaskets and fenestration. The rate of material deterioration and properties determine the usefulness of a product; therefore, knowledge of the significant degradation mechanisms in play for BEMs is key to the design of proper SLP methods. SLP seeks to estimate the life expectancy of a material/component exposed to in-service conditions. This topic is especially important with respect to the potential impacts of climate change. The surrounding environment of a building dictates the degradation mechanisms in play, and as climate change progresses, material aging conditions become more unpredictable. This can result in unexpected changes and/or damages to BEMs, and shorter than expected SL. The development of more comprehensive SLP methods is economically and environmentally sound, and it will provide more confidence, comfort and safety to all building users. The goal of this paper is to review the existing literature in order to identify the knowledge gaps and provide suggestions to address these gaps in light of the rapidly evolving climate.

Determining the thermal resistance of a highly insulated wall containing vacuum insulation panels through experimental, calculation and numerical simulation methods

2020 ◽  
pp. 174425912098003
Author(s):  
Travis V Moore ◽  
Cynthia A. Cruickshank ◽  
Ian Beausoleil-Morrison ◽  
Michael Lacasse
Keyword(s):  
Thermal Conductivity ◽  
Thermal Resistance ◽  
Effective Thermal Conductivity ◽  
Edge Effect ◽  
3D Simulation ◽  
Simulation Methods ◽  
Zone Method ◽  
Vacuum Insulation ◽  
Thermal Bridges ◽  
Wall Assembly

The purpose of this paper is to investigate the potential for calculation methods to determine the thermal resistance of a wall system containing vacuum insulation panels (VIPs) that has been experimentally characterised using a guarded hot box (GHB) apparatus. The VIPs used in the wall assembly have not been characterised separately to the wall assembly, and therefore exact knowledge of the thermal performance of the VIP including edge effect is not known. The calculations and simulations are completed using methods found in literature as well as manufacturer published values for the VIPs to determine the potential for calculation and simulation methods to predict the thermal resistance of the wall assembly without the exact characterisation of the VIP edge effect. The results demonstrate that disregarding the effect of VIP thermal bridges results in overestimating the thermal resistance of the wall assembly in all calculation and simulation methods, ranging from overestimates of 21% to 58%. Accounting for the VIP thermal bridges using the manufacturer advertised effective thermal conductivity of the VIPs resulted in three methods predicting the thermal resistance of the wall assembly within the uncertainty of the GHB results: the isothermal planes method, modified zone method and the 3D simulation. Of these methods only the 3D simulation can be considered a potential valid method for energy code compliance, as the isothermal planes method requires too drastic an assumption to be valid and the modified zone method requires extrapolating the zone factor beyond values which have been validated. The results of this work demonstrate that 3D simulations do show potential for use in lieu of guarded hot box testing for predicting the thermal resistance of wall assemblies containing both VIPs and steel studs. However, knowledge of the VIP effective thermal conductivity is imperative to achieve reasonable results.

Preparation and characterization of vacuum insulation panels with super-stratified glass fiber core material

Energy ◽  
2015 ◽  
Vol 93 ◽  
pp. 945-954 ◽  
Author(s):  
Zhou Chen ◽  
Zhaofeng Chen ◽  
Zhaogang Yang ◽  
Jiaming Hu ◽  
Yong Yang ◽  
...  
Keyword(s):  
Glass Fiber ◽  
Core Material ◽  
Fiber Core ◽  
Vacuum Insulation

Field temperature and moisture loads from a building envelope as the basis for accelerated aging of barrier membranes

2019 ◽  
Vol 46 (11) ◽  
pp. 969-978 ◽  
Author(s):  
Marzieh Riahinezhad ◽  
Augusta Eve ◽  
Marianne Armstrong ◽  
Peter Collins ◽  
J.-F. Masson
Keyword(s):  
Building Materials ◽  
National Research Council ◽  
Accelerated Aging ◽  
Bimodal Distribution ◽  
Building Envelope ◽  
Rate Of Change ◽  
Single Family ◽  
Field Exposure ◽  
Aging Conditions ◽  
Materials Used

Temperature and relative humidity (RH) data within the building envelope of a single-family home at the National Research Council of Canada’s Canadian Centre for Housing Technology were collected over five years. We report on the distribution, rate of change, and the limits of temperature and moisture variations for south-easting wall and south-facing wall and roof systems to better understand the in-situ environmental conditions to which building materials and components typical of homes in North America may be subjected. Over an average year, wall temperature varied from −25 °C to +45 °C, and temperature followed a bimodal distribution, with maxima at 0 °C to 5 °C and 15 °C to 20 °C. Each maximum represented about 1100 h of field exposure. Roof temperatures, which spanned a temperature range from −35 °C to 75 °C, did not show a Gaussian distribution but were characterized as being multi-modal. From values of temperature and RH, absolute moisture contents within the building envelope were found to range between 1 and 55 g/m3, with the most common values being 6–8 g/m3. The application of this information is discussed and related to the development of realistic accelerated aging conditions to obtain a more accurate durability assessment of building envelope materials used in Canadian dwellings.

Service Life Prediction for the Neoprene Used in Seawater

2013 ◽  
Vol 739 ◽  
pp. 85-89
Author(s):  
Qing Zhen Wen ◽  
Chao Yu ◽  
Jin Hua Zhu
Keyword(s):  
Service Life ◽  
Aging Time ◽  
Life Prediction ◽  
Sea Water ◽  
Accelerated Aging ◽  
Service Life Prediction ◽  
Exponential Form ◽  
Prediction Functions

The heat seawater method was designed and the accelerated aging tests of the neoprene were carried in laboratory. The toughness and strength of the neoprene in aging time was investigated. The rule of toughness and strength and aging time was studied. The service life prediction functions of the neoprene were established and service life at 25°C was estimated based on the index of toughness and strength. It is concluded that toughness and strength of the neoprene decreases in exponential form with aging time, and the service life of the neoprene used in sea water at 25°C is 29.5 years.

scholarly journals Thermal insulation properties of green vacuum insulation panel using wood fiber as core material

BioResources ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. 3339-3351 ◽  
Author(s):  
Baowen Wang ◽  
Zhihui Li ◽  
Xinglai Qi ◽  
Nairong Chen ◽  
Qinzhi Zeng ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Bulk Density ◽  
Thermal Insulation ◽  
Wood Fiber ◽  
Core Material ◽  
High Porosity ◽  
Total Thermal Conductivity ◽  
Wood Fibers ◽  
Vacuum Insulation ◽  
Vacuum Insulation Panel

Wood fibers were prepared as core materials for a vacuum insulation panel (VIP) via a dry molding process. The morphology of the wood fibers and the microstructure, pore structure, transmittance, and thermal conductivity of the wood fiber VIP were tested. The results showed that the wood fibers had excellent thermal insulation properties and formed a porous structure by interweaving with one another. The optimum bulk density that led to a low-cost and highly thermally efficient wood fiber VIP was 180 kg/m3 to 200 kg/m3. The bulk density of the wood fiber VIP was 200 kg/m3, with a high porosity of 78%, a fine pore size of 112.8 μm, and a total pore volume of 7.0 cm3·g-1. The initial total thermal conductivity of the wood fiber VIP was 9.4 mW/(m·K) at 25 °C. The thermal conductivity of the VIP increased with increasing ambient temperature. These results were relatively good compared to the thermal insulation performance of current biomass VIPs, so the use of wood fiber as a VIP core material has broad application prospects.

In Situ Measurement of Thermal Resistance of Building Envelope at the Residential Occupancy in Indonesia

2015 ◽  
Vol 771 ◽  
pp. 191-194 ◽  
Author(s):  
Wahyu Sujatmiko ◽  
Hermawan Kresno Dipojono ◽  
F.X. Nugroho Soelami ◽  
Soegijanto
Keyword(s):  
Thermal Resistance ◽  
High Performance ◽  
Building Materials ◽  
Precast Concrete ◽  
Green Building ◽  
Building Envelope ◽  
Building Wall ◽  
Ashrae Standards ◽  
Building Walls

Abstract. This paper presents the measurement results of three building wall materials which are commonly used for residential housings in Indonesia, namely clay brick, batako (concrete brick), and precast concrete. In-situ measurement of the steady state thermal flow (heat flux) at building walls (envelopes) is conducted in order to determine the thermal resistance of building wall according to ASTM C1155. The results show that all three building materials having a thermal resistance values are far below the energy conservation provisions of ASHRAE 90.1 and especially when compared to the provision of high performance green building ASHRAE 189.1 It is found that precast concrete has higher thermal resistance (or has lower thermal conductivity) than that of other two materials, hence a better compliance to the ASHRAE standards.

scholarly journals Analysis and Prediction of Thermal Resistance for High Power LED Using GA-SVR

2012 ◽  
Vol 4 ◽  
pp. 153-160
Author(s):  
De Huai Zeng ◽  
Yuan Liu ◽  
Li Li ◽  
De Gui Yu ◽  
Gang Xu
Keyword(s):  
Service Life ◽  
Thermal Resistance ◽  
High Power ◽  
Thermal Characteristics ◽  
Junction Temperature ◽  
Support Vector ◽  
Mean Squared Errors ◽  
Absolute Relative Error ◽  
High Power Led ◽  
Key Factor

With the development of high power LED technology, junction temperature as a key factor constrains the performance and the service life of LED, and the main parameter of junction temperature is thermal resistance. Therefore, how to measure the thermal resistance of high power LED quickly and accurately plays an important part in improving the performance and the service life of LED. In this paper the accurate and fast measurement equipment was applied to study the thermal characteristics of high power LED. The forward-voltage based method was conducted to measure the junction temperature of high power. Then, support vector regression (SVR) combined with genetic algorithm (GA) for its parameter optimization, was proposed to establish a model to predict the thermal resistance of high power LED. The prediction performance of GA-SVR was compared with those of BPNN model. The result demonstrated that the estimated errors GA-SVR models, such as Mean Absolute Relative Error (MARE) and Root Mean Squared Errors (RMSE), all are smaller than those achieved by the BPNN applying identical samples.

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