ENERGY STAR qualified, windows, doors, and skylights:
- Are manufactured by an ENERGY STAR partner,
- Are independently tested, certified, and verified by the National Fenestration Rating Council (NFRC), and
- Have NFRC ratings that meet strict energy efficiency guidelines set by the US Environmental Protection Agency (EPA).
Though ENERGY STAR does not require any specific technologies, certain product features are common in many certified products.
Performance Criteria
Windows, doors and skylights protect you from the elements just like a winter coat. But like a winter coat, you should pick the windows, doors and skylights that make the most sense for your climate. While some windows, doors and skylights are better at keeping you warm, others excel at keeping you cool.
Performance criteria for windows and skylights are based on ratings certified by the National Fenestration Rating Council (NFRC), and vary for each of the climate zones shown in the map above.
Source:.https://www.energystar.gov/products/building_products/residential_windows_doors_and_skylights/key_product_criteria
