what is spandrel glass panels
Unlike vision glass, which is meant to be transparent, spandrel glass is designed to be opaque in order to help hide features between the floors of a building, including vents, wires, slab ends and mechanical equipment. All glass used in a spandrel should be heat-strengthened to resist the thermal stresses associated with potential heat absorption and build-up. 2  PPG recommends placing the opacifier on the fourth surface of the IG to avoid the potential release of vocs inside the IG.