In situ U _g-value measurement on three different glazing types

Abstract

This study presents in situ monitoring data of three different glazing systems over a period of one year. An insulated glass unit (IGU), a Vacuum Insulated Glass hybrid unit (VIG-hybrid) and an opaque architectural insulation module (AIM) were monitored under the equivalent environmental condition in this study. Different issues were observed and analyzed. It was found that the Ug-value cited by the manufacturers agrees with the Ug-values derived from the measured data, to within less than 5 % for the IGU and the VIG-hybrid. The consistency of the Ug-value of each glazing types one year after the start of monitoring was validated for similar environmental conditions. Depending on the magnitude of the resistance to heat flow, an increasing Ug-value was observed for a higher temperature difference between the inside and outside environments. The effect is much more significant for the glazing type with the largest Ug-value (IGU) and less significant for the glazing types with a high thermal resistance (VIG-hybrid, AIM).

Case Studies on the Thermally Induced Stresses in Insulating Glass Units via Numerical Calculation

“…In the numerical simulation, a simplified finite element volume body model is generated in order to calculate the thermal transmittance U g of the glazing with the help of the cavity heat transfer coefficient h cavity = 1.28 W/(m 2 K) calculated in Section 4.2. It should be noted that edge spacers and frame construction have no influence on the U g -value (Paschke et al 2021) and therefore do not need to be represented in the model. In this sense, the numerical model shown in Fig.…”