The most effective way to reduce air-to-air heat transfer through glass
Insulating glass units (or “IG units”) improve thermal performance by providing a thermal break – two or more lites separated by a sealed air space. This enables the glass to meet two very different requirements – keeping heat in during colder weather and keeping heat out during warmer weather.
Insulating glass is a very effective way to reduce air-to-heat transfer through the glazing. When used in conjunction with low-E and/or reflective coatings, IG units perform even better for conserving energy and complying with local codes. The most common configuration of IG units for commercial building is a 6 mm lite, 12mm of air space and a 6mm lite.
Please note: for use as vision glass, SunGuard Advanced Architectural Glass should always be insulated with the coating facing the air space, most often on the #2 surface.
As low-E coatings have become better at reducing air-to-air heat transfer, spacer technology has become the focus of incremental thermal improvements. Typical commercial spacers are composed of formed aluminum filled with desiccant to absorb any residual moisture inside the IG unit, thus reducing potential condensation. While this is a structurally strong material, the aluminum-to-glass contact point is a very efficient thermal conductor and can increase the potential for temperature differential between the center of glass and the edge of glass, which can lead to condensation and reduces the unit’s overall U-value.
SunGuard coatings provide substantial improvements – up to 50 percent in U-values and solar heat gain coefficients compared to uncoated insulating glass units. In addition, new “warm-edge” spacer materials can lower the U-value further.