The Ultra-R direct set window uses Southwall Technologies’ Heat Mirror technology that results in a center-of-glass R-value of 20. Heat mirror films are coated with nano-scale metal particles that reflect heat back to its source, which improves insulation, blocks UV rays, and reduces noise. The window has a total unit R-value of 9 and is 33 percent lighter than triple-pane units, says the manufacturer. Hurd Windows & Doors, 800.433.4873;

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