Designed to deliver triple-pane performance in a dual-glazed configuration, Cardinal Glass Industies' LoE-i81 is manufactured using the latest innovation in sputter coating technology applied on the interior lite of an IG unit, or the #4 surface of a double-pane window. When coupled with Cardinal LoE3-366, glass and argon fill in a double-pane IG unit, the center of glass U-factor is only 0.20, according to the supplier. Without argon and with or without capillary tubes, the unit still delivers a U-factor of just 0.23—perfect for high altitudes, it is noted. The new glass allows more window designs to meet current Energy Star guidelines in a double-pane configuration, eliminating the need to invest in redesigning windows and altering manufacturing processes, the manufacturer states. It also has a visible light transmittance of 81 percent, virtually clear with no haze to mar the view.