How are the ratings measured?
On a scale of 1-100%…100 being the best. Based on the information you enter about your building, such as its size, location, number of occupants, number of PCs, etc., the score's algorithm estimates how much energy the building would use if it were the best performing, the worst performing, and every level in between.
Where do I find the ratings on the products?
Our manufactures provide the ratings information on the sales order acknowledgments and on the product stickers (PGT). You are looking for the NFRC’s tested ratings.
What is the NFRC?
NFRC is short for the National Fenestration Rating Council, which is a non-profit that established standardized ways to test the performance of windows and doors. The ratings they offer give consumers detailed info about how energy performance, which gives them more information to make the most informed decision.
What is U Factor?
U-factor is the rate at which a window, door, or skylight transmits non-solar heat flow. For windows, skylights, and glass doors, a U-factor may refer to just the glass or glazing alone. NFRC U-factor ratings, however, represent the entire window performance, including frame and spacer material.
What is SHGC?
Solar heat gain coefficient (SHGC) is the fraction of solar radiation admitted through a window, door, or skylight -- either transmitted directly and/or absorbed, and subsequently released as heat inside a home. The lower the SHGC, the less solar heat it transmits and the greater its shading ability.