Grandview

The vinyl mainframes of GrandView™ 4000 windows are filled with patented^† R-Core^® insulation (pre-expanded high-density solid-polyurethane), the same type used in many refrigerator/freezer doors. It prevents voids and settling and results in even distribution of the maximum insulating barrier. GrandView™ 5000 windows feature additional R-Core^® in the sash for the ultimate in thermal performance and warmth.

†U.S. Patent Number: 4,516,356

GrandView™ 4000 features R-Core^® insulation in all frame components.	GrandView™ 5000 features R-Core^® insulation in all frame and sash components for maximum energy performance.
R-Core^® Insulation The vinyl mainframes of GrandView™ 4000 windows are filled with patented^† R-Core^® insulation (pre-expanded high-density solid-polyurethane), the same type used in many refrigerator/freezer doors. It prevents voids and settling and results in even distribution of the maximum insulating barrier. GrandView™ 5000 windows feature additional R-Core^® in the sash for the ultimate in thermal performance and warmth. †U.S. Patent Number: 4,516,356