4th Surface Technology



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Low-E 4th Surface Technology from Pilkington allows a double-glazed IG unit to achieve a 12 percent improved thermal performance over a triple-pane unit, the company states. Adding a pyrolytic low-E coating to the #4 surface of the unit reflects infrared heat back into the home, reducing the amount of radiant heat loss through the glass. Infrared heat is room heat generated inside a building at or near room temperature. In cold weather conditions, a low-E coating on the #2 surface inhibits room heat from transferring across the air space toward the outside. By adding a second low-E coating to the #4 surface, the thermal insulation is further improved by reflecting room heat back inside. This reduces the radient heat loss and improves the overall insulation of the IG. Applying two pyrolytic low-E lites in an IG unit reduces the center-of-glass U-factor by 45 percent, compared to an IG unit with two panes of standard clear, it is reported.  The manufacturer of Energy Advantage glass also reports that the product has been enhanced to dramatically increased its clarity, improving homeowners views and aesthetics, while maintaining the benefits of enhanced insulation and high solar heat gain. The latest advancements in coating technology reduce the haze value of the glass to a level so low that is difficult to perceive and still has no off-angle color as found with some sputter coated glass products, the company states.