Evaluation of Core Material in Structured-core Transparent Vacuum Insulation Panels For Windows: Numerical and Experimental Analysis

The conversion of existing buildings to net zero-energy houses and net zero-energy buildings requires increased overall thermal insulation, in which the insulation of window surfaces is particularly important and effective route. The authors’ research group has proposed a form of transparent vacuum insulation panels (TVIP), which could be used as simple and easy to install insulation to building windows. In this study, several 3D-printed core types were simulated and experimentally measured to compare the effectiveness of different core architectures as well as added vacuum layers. It was found that while there were differences between frame and peak type cores, these became negligible with smaller core spans, and largely disappeared when attached to a windowpane. A second layer of vacuum improved the sample core’s overall heat transfer by 50 percent, while a third layer brought only a 24 percent improvement. Added benefits brought by the additional layers thus need to be balanced with the additional thickness inherent in the decision. It was also proven from experiments, that U
TVIP
of a single frame type core with double low-E films was 1.7 [W/(m
²
K)], and the U
TVIP
of double vacuum layer TVIP were 1.4 [W/(m
²
K)]. Higher insulation performance can thus be achieved in both ways. The created ANSYS model’s predictions followed physical test results closely, validating said model as a tool for further structured-core experiments.