Application and Effect of Low-Emission Coating for Reducing U-Value of Vacuum Glazing
Sanghoon Baek1, Sangchul Kim2

1Sanghoon Baek, Department of Industry Academic Cooperation Foundation, Han Kyong National University,  Jungang-Ro, Anseong-Si, Gyeonggi-Do, South Korea.

2Sangchul Kim, School of Architecture, Han Kyong National University, Jungang-Ro, Anseong-Si, Gyeonggi-Do,  South Korea

Manuscript received on 10 June 2019 | Revised Manuscript received on 17 June 2019 | Manuscript Published on 22 June 2019 | PP: 710-716 | Volume-8 Issue-8S2 June 2019 | Retrieval Number: H11190688S219/19©BEIESP

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Abstract: In recent years, as the advanced window system, vacuum glazing with a low thermal transmittance (U-value) of under 1.0 W/m2∙K are actively being developed worldwide. Vacuum glazing comprises only two panes of glass with a vacuum space between them, and do not include the use of insulating gas. Thus, unlike existing multi-pane windows, heat transfer occurs only by radiation from the glass surfaces. In addition, to reduce the U-value of a vacuum glazing by a considerable amount, it is necessary to minimize the emissivity of the glass surfaces. The application of a low emissivity coating to the glass surfaces that are in contact with the vacuum layer has recently been introduced. In this study, a computer simulation was conducted to analyze the effects of reducing the surface emissivity on the U-value for vacuum glazing, as well as for double-pane glazing filled with air, argon, and krypton. The results showed that, for double-pane glazing filled with air, Ar, and Kr, when the emissivity of the glass surfaces, #2 and #3 was reduced gradually from 0.8 to 0.1 in steps, the U-value decreased from 13.41% to 50.65%. Meanwhile, for vacuum glazing, when the emissivity of the glass surfaces in contact with the vacuum cavity was reduced from 0.8 to 0.1, from 18.07% to 67.04%. Therefore, to reduce the U-value of the vacuum glazing, glass with a low-e coating is effective, especially. This research suggested to applying #3 or #4 coating of its glass surface to reach a lower U-value than the double-pane glazing with Kr and the glass with emissivity, 0.1.

Keywords: Double-Pane Glazing, Emissivity, Low-Emission Coating, U-Value, Vacuum Glazing.
Scope of the Article: Evaluation of Glazing Systems for Energy Performance