HFM – Window Glass – Thermal transmittance – Horizontal vs. Vertical Measurement
Inhomogeneous glass sample – U-value – Thermal Conductivity
A 3-layer window glass with argon filler has been investigated by Linseis HFM 300 in the temperature range from 10 °C to 50 °C. The measurement was performed in a horizontal (standard) and vertical setup.
The diagram shows a significant difference in the U-value results between vertical and horizontal measurement setup, which are due to convection effects within the insulation layer. This measurement clearly indicates that inhomogeneous building materials need to be measured in the direction of their final use to get accurate values of the thermal conductivity and the thermal transmittance (U-value).