Gorell vinyl windows and doors that incorporate any of Gorell's six low-emissivity (Low-E) insulating glass systems pass ENERGY STAR® requirements and therefore carry ENERGY STAR® labels.

The ENERGY STAR label can be affixed only to products that meet specific U-value and shading coefficient ratings for one or more regions of the U.S.  These ratings are achieved through independent testing done to NFRC* standards.

You can also check-out www.energystar.gov

 * National Fenestration Ratings Council, a federal program created to establish standardized testing procedures and ratings of window and door products.