Alpen HPP X25 series combines a fully-insulated framing systems with spectrally selective glass packages to achieve high insulation performance across the full-frame — not just measured at center of glass.

• Inert gas fill, with a choice of argon or krypton
• Suspended film reduces convection and energy transfer without the weight and size of a third pane of glass
• Wide IG for better thermal insulation and better noise-reducing performance
• Wet glazing to minimize air leakage at the glass-to-sash bond, increasing insulation performance