Purchasing energy-efficient windows will help you save on energy costs and improve your home’s overall comfort. There are two labels that you should look out for when you’re looking to purchase windows or sliding patio doors: the National Fenestration Rating Council® (NFRC), and ENERGY STAR® labels.
NFRC® vs. ENERGY STAR®
The NFRC is a third-party non-profit organization that serves as the industry-recognized certifying body for windows and doors. They aim to help consumers compare the performance of doors, windows and skylights. However, the labels do not directly reflect whether a product is bad or good, but they set minimum performance standards or mandate performance levels.
ENERGY STAR ratings act as a supplement to NFRC labels. ENERGY STAR tests windows, skylights and doors in accordance with the standards set by the NFRC. All ENERGY STAR-labeled products have also met stringent energy efficiency requirements set by the U.S. government
NFRC Performance Ratings
Solar heat gain coefficient (SHGC): The SHGC refers to the amount of solar radiation a window or door allows inside. Those who are situated in warmer areas should opt for windows or patio doors with a low SHGC rating while those living in cooler areas should go for a higher rating.
U-Factor: The U-factor is an indicator of a unit’s rate of heat transfer and insulation performance. The lower the number, the better an insulator the window or door is.
Air leakage (AL): AL rating refers to the amount of air that passes through the joints of a door or window. The lower the air leakage rating, the more airtight the unit is. This number is measured in cubic feet per minute per square foot of window or door area. However, this rating isn’t considered as much for ENERGY STAR due to external factors, such as frame materials expanding or warping. It’s still an important metric nonetheless especially if you live in an area with harsh weather.
Condensation resistance: This number indicates how well a window withstands water or moisture buildup. The higher the number, the better the resistance.
Visible transmittance (VT): This rating refers to the amount of light a window or skylight lets through. The higher the VT rating, the more light enters your home. Through advancements in glass technology, this doesn’t let as much heat enter despite the amount of light passing through into your home.
Do you need energy-efficient windows and French doors? Check out our selection at Renewal by Andersen® of St. Louis! Call us at (314) 983-9977, or fill out our contact form for a FREE estimate! We serve St. Louis and the rest of Missouri!