Measurement of VIP Edge Conduction Using Vacuum Guarded Hot Plate

Vacuum insulation panel (VIP) is a promising thermal
insulator for buildings, refrigerator, LNG carrier and so on. In general,
it has the thermal conductivity of 2~4 mW/m·K. However, this thermal
conductivity is that measured at the center of VIP. The total effective
thermal conductivity of VIP is larger than this value due to the edge
conduction through the envelope. In this paper, the edge conduction of
VIP is examined theoretically, numerically and experimentally. To
confirm the existence of the edge conduction, numerical analysis is
performed for simple two-dimensional VIP model and a theoretical
model is proposed to calculate the edge conductivity. Also, the edge
conductivity is measured using the vacuum guarded hot plate and the
experiment is validated against numerical analysis. The results show
that the edge conductivity is dependent on the width of panel and
thickness of Al-foil. To reduce the edge conduction, it is recommended
that the VIP should be made as big as possible or made of thin Al film
envelope.

• Bongsu Choi
• Tae-Ho Song

• Envelope
• Edge conduction
• Thermal conductivity
• Vacuum insulation panel.

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