• Journal of Surface Science and Engineering
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• v.55 no.6
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• pp.398-402
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• 2022

Vacuum Insulation Panel (VIP) is an high energy efficient insulation system that facilitate slim but high insulation performance, based on based on a porous core material evacuated and encapsulated in a multi-barrier envelope. Although VIP has been on the market for decades now, it wasn't until recently that efforts have been initiated to propose a standard on aging testing. One of the issues regarding VIP is its durability and aging due to pressure and moisture dependent increase of the initial low thermal conductivity with time. It is hard to visually determine at an early stage. Recently, a method of analyzing the damage on the a material surface by applying image processing technology has been widely used. These techniques provide fast and accurate data with a non-destructive way. In this study, the surface VIP images were analyzed using the Harris corner detection algorithm. As a result, 171,333 corner points in the normal packaging were detected, whereas 32,895 of the defective packaging, which were less than the normal packaging. were detected. These results are considered to provide meaningful information for the determination of VIP condition.

• Journal of the Korean Solar Energy Society
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• v.37 no.4
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• pp.35-47
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• 2017

Energy efficiency solutions are being pursued as a sustainable approach to reducing energy consumption and related gas emissions across various sectors of the economy. Vacuum Insulation Panel (VIP) is an energy efficient advanced insulation system that facilitates slim but high-performance insulation, based on a porous core material evacuated and encapsulated in a barrier envelope. Although VIP has been applied in buildings for over a decade, it wasn't until recently that efforts have been initiated to propose and adopt a global standard on characterization and testing of VIP. One of the issues regarding VIP is its durability and aging due to pressure and moisture dependent increase of the initial low thermal conductivity with time; more so in building applications. In this paper, the aging of commercially available VIP was investigated experimentally; thermal conductivity was tested in accordance with ISO 8302 standard (guarded hot box method) and long-term durability was estimated based on a non-linear pressure-humidity dependent equation based on study of IEA/ECBCS Annex 39, with the aim of assessing durability of VIP for use in buildings. The center-of-panel thermal conductivity after 25 years based on initial 90% fractile with a confidence level of 90 % for the thermal conductivity (${\lambda}90/90$) ranged from 0.00726-0.00814 (W/m K) for silica core VIP. Significant differences between manufacturer-provided data and measurements of thermal conductivity and internal pressure were observed.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.8
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• pp.471-476
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• 2013

The present study has been carried out to elucidate the optimal method for the performance test of a refrigerator vacuum insulation panel (VIP), by using numerical heat transfer analysis. Three locations of heat flux meter have been tested, for deriving the best test method to clarify the normal or the abnormal condition of the vacuum insulation panel in a refrigerator. The first location of the heat flux sensor is at the same place as the heater, the second one is at the nearby side location of the heater and the third one is at the opposite side location of heater in the refrigerator. The heat flux and $1/q^{{\prime}{\prime}^2}$ or $q^{{\prime}{\prime}^4}$ were calculated for the cases with the normal VIP, and with the abnormal VIP, and their differences analyzed. From the present study, the first and the second method had a mere difference characteristics of heat flux and $1/q^{{\prime}{\prime}^2}$ or $q^{{\prime}{\prime}^4}$, between the cases with the normal or the abnormal VIP. The magnitude of the heat flux after 300sec had a great difference between the cases with the normal or abnormal VIP for the third method, and it could be considered the most optimal method to test the performance of a refrigerator vacuum insulation panel.

• Land and Housing Review
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• v.10 no.3
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• pp.23-32
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• 2019

Vacuum Insulation Panel(VIP) has the lowest thermal conductivity among present insulations. It is composed of envelope, core material and getter. Aluminum film is usually used as the envelope of VIP, and it is important component to decide the useful life of VIP. In this research, the thermophysical properties of incombustible fiber glass core VIP were investigated with the possibility of its architectural applications. The results of this research can be summarized as follows: 1) The thermal conductivity of 20mm-thick fiber glass core VIP is resulted as 0.00177W/m·K, which means that 20mm-thick VIP can meet all the reinforced insulation guideline and it can be used in any envelope of any region in Korea. 2) As a result of the test of incombustion and gas toxicity, fiber glass core VIP was suitable for incombustible material. 3) As the test result for the long term thermal conductivity, fiber glass core VIP was found out that it would keep above 10 times insulating performance than polystyrene foam and glass fiber. 4) To meet the thermal transmittance of 0.12W/㎡K, limited-combustible insulation of expanded polystyrene foam and phenolic foam should be used respectively as thick as above 280mm and 170mm, incombustible VIP can meet the same insulation level with 20mm thickness. 5) The price competitiveness of incombustible VIP to meet the thermal transmittance of 0.12W/㎡·K was about 1,500won/㎡ higher than that of phenolic foam.

• Journal of the Korea Institute of Building Construction
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• v.20 no.5
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• pp.417-423
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• 2020

In order to reduce cooling and heating, which is 40% of the energy consumption of buildings, it is important to improve the insulation of the skin. In order to improve the existing insulation, research is being conducted to apply a vacuum insulation panel(VIP) to buildings. However, VIP cannot be repaired, so we considered the metal vacuum insulation panel. Since the core of the metal vacuum pressure and have low thermal conductivity, foam concrete is adopted. However, preliminary experiments confirmed that the time to reach 0.001torr differs depending on the amount and nature of the bubbles. This effect is determined by the type of foaming agent and the density of the bubble slurry, the vacuum delivery time is determined to be the optimum foam concrete conditions are necessary. Therfore, this study aims to present basic data applicable to core materials by measuring vacuum delivery time and thermal conductivity change according to the foaming agent type and foam slurry density of foam large concrete which is core material of metal vacuum insulation panel. Experimental results and analysis show that compressive strength can be used regardless of the type of foam, In terms of thermal conductivity, it is stable to use vegetable foaming agents at 0.9g/㎤ or less. In terms of the vacuum delivery time, the foaming agent appeared similar regardless of the type of foaming agent, but it is considered suitable to use vegetable foaming agent based on compressive strength and thermal conductivity.

• KIEAE Journal
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• v.13 no.6
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• pp.45-53
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• 2013

For the target goal of Zero-energy House construction in 2025, the government announced that the insulation regulations will be continuously enhanced. It has been predicted that high-performance insulation materials, such as vacuum insulation panel (VIP), should be used to decrease the thickness of outer walls. The aim of this study was to evaluate the performance of adhesively fixed external insulation and finish system (EIFS) with VIP. The energy performance of a base model with conventional internal insulation system and three alternatives of EIFS with VIP were analyzed by three-dimensional heat transfer simulation. Construction cost and convenience of each alternative were also evaluated and compared. As results, effective alternatives in terms of each performance as well as overall performance considering the weighting factors of each performance were suggested.

• KIEAE Journal
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• v.16 no.1
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• pp.5-10
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• 2016

Purpose: The energy consumption in buildings has continuously increased in some countries and it reaches almost 25% of the total energy use in korea. Therefore there are various efforts to minimize energy consumption in buildings, and the regulations on building envelope insulation have been tightened up gradually. To satisfy the building regulation, the use of vacuum insulation panels(VIPs) is increasing. VIP is a high performance insulation materials, so that it can be thinner than conventional insulation material. When VIP is applied in a building, it may cause thermal bridge, which occurs due to very low thermal conductivity compared to other building materials and the envelope of VIPs. Method: This study designed the capsulized VIPs using conventional insulation for reduction of the thermal bridge. Then designed VIPs were applied to a wall. The linear thermal transmittance and the effective thermal conductivity were analyzed by HEAT2 simulation program for two dimensional steady-state heat transfer. The result compared with a wall with non-capsulized VIPs. Result: It analyzed that the wall with capsulized VIPs had lower linear thermal transmittance and reduced the difference of the effective thermal transmittance with one dimensional thermal transmittance compared to that of the wall with non-capsulized VIPs.

• Clean Technology
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• v.18 no.1
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• pp.14-21
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• 2012

The pros and cons of green building thermal insulation materials and systems have been reviewed from traditional thermal insulation materials such as mineral wool and polyurethane to new thermal insulation materials like VIP and aerogel and future insulating VIM and DIM. VIPs and aerogels with very low thermal conductivity can use for green buildings to significantly increase residential area by reducing energy consumption. Aerogels can be produced as not only opaque and but also translucent forms, thus enabling a wide range of possible building application. For building applications, there are many properties to consider like building site adaptability and mechanical strength, fire protection, cost and environmental impact.

• Elastomers and Composites
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• v.50 no.1
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• pp.30-34
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• 2015

Thermo-mechanical treatment process of a compressed open-cell rigid polyurethane foam (OC-RPUF), which was fabricated for the vacuum insulation panel (VIP), was studied to obtain an optimum condition for the dimensional stability by the relaxation of compressive stress. Thermo-mechanical deformation of the sample OC-RPUF was shown to occur from about $120^{\circ}C$. Yield stress of 0.36 MPa was shown at about 10% yield strain. And, densification of the foam started to occur from 75% compressive strain and could be continued up to max. 90%. Compression set of the sample restored after initial compression to 90% at room temperature was ca. 82%. Though the expansion occurred to about twice of the originally compressed thickness in case of temperature rise to $130^{\circ}C$, it could be overcome and the dimensional stability could be maintained if the constant load of 0.3 MPa was applied. As the result, a thermo-mechanical treatment process, i.e, annealing process at temperature of $130{\sim}140^{\circ}C$ for about 20 min as is the maximum compressed state at room temperature, should be required for dimensional stability as an optimum condition for the use of VIP core material.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.8
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• pp.727-734
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• 2015

Currently, polyurethane (PU) foam is used in most refrigerators as a thermal insulator, whereby the material contributes to structural stiffness by joining the refrigerator cases; however, refrigerator PU foam induces a low thermal efficiency and results in environmental contamination. To resolve these issues, we applied the vacuum insulated panel (VIP) instead of PU form in the design of a new refrigerator type, whereby the VIP significantly contributes to the rectification of the previously mentioned issues. The VIP structure, however, cannot effectively hold refrigerator cases, so the present study investigated a new frame-structure concept by evaluating the stiffness using the topology optimization of refrigerator cases. Lastly, a refrigerator prototype comprising an optimal frame structure was built and subject to a stiffness test, and a comparison of the test results with those of a conventional refrigerator show that the structural stiffness of the prototype is sufficiently effective.