• A 3-1/4" frame profile adds structural integrity and allows for better energy performance.
• 7/8" insulated glass unit with double strength glass features the EnviroSeal nXt™ warm-edge glass spacer. This warm-edge no metal spacer keeps your energy costs low by keeping heat out during the summer and in during the winter. 
• A roller tilt constant force balance system means you can count on your ventilating windows to open smoothly and quietly regardless of size, plus no maintenance concerns.
• Raised contoured exterior profile adds dimension and style to a simply designed window.
• The multi-chambered design of the frame and sash components with heavy wall thickness enhances the structural and thermal performance of the window.
• Interlocks at the meeting rail are wide and deep and feature dual FinSil weatherstripping for improved thermal and structural ratings.
• The sash and frame are entirely fusion welded to meet the strictest guidelines for structural needs.
• A true slope sill design protects the integrity of the window even in extreme weather and driving rains.
• The meeting rail is reinforced with metal to improve structural performance with hardware is attached.
• Locking pivot shoe system for added structural integrity and protection.
• Double wall interior leg with weatherstripping for improved seal.
• Some styles have a tilt sash feature that makes it easy to clean the exterior side of the glass without having to step outside.

EnviroSeal nXt

EnviroSeal nXt outperforms other single-seal and dual-seal spacers. Windows built with EnviroSeal nXt exhibit the lowest failure rates in the industry which is ideal with insulated glass units. Considered the glass spacer of the future, this warm-edge glass spacer is highly energy efficient. 

Designed without metal, the spacer conducts less thermal energy thus improving the edge of glass temperature by as much as 16.6° F when compared to other spacer systems. By regulating the thermal transfer, windows with EnviroSeal nXt technology will keep your home comfortable year round. 

Cardinal LoÉ3-366 offers the ultimate experience in window performance glass. This glass delivers the perfect balance of solar heat control and high visibility. It also provides peak levels of year-round comfort and energy savings, making it the perfect glass regardless of which part of the country you live. With three layers of silver on the glass, you are certain to enjoy year-round thermal protection all day, every day.

Installing ENERGY STAR® qualified windows lowers energy bills and saves you money over single-pane and even new double-paned, clear-glass windows. Windows with our high-performance glass package are ENERGY STAR® qualified for all regions.