For help gauging energy efficiency, look for a product's Solar Heat Gain Coefficient (SHGC) rating and U-values. The SHGC rating will tell you how effective the product is at blocking the heat caused by the sun (the lower the number, the less heat it allows in). U-values indicate how well the product keeps heat inside a home (the lower the number, the better it insulates). Pella's products offer some of the lowest U-values in the industry. Most Pella® products with Low-E insulating glass meet or exceed ENERGY STAR® guidelines in all 50 states. In fact, we have some products that have U-values that significantly exceed U.S. ENERGY STAR guidelines.
ENERGY STAR Requirements for Canada