National Fenestration Rating Council
is a non-profit, public/private organization created by the window, door and skylight industry. It is comprised of manufacturers, suppliers, builders, architects and designers, specifiers, code officials, utilities and government agencies. NFRC provides consistent ratings on window, door and skylight products.
The NFRC Label
- The National Fenestration Rating Council (NFRC) energy performance label can help you determine how well a product will perform the functions of helping to cool your building in the summer, warm your building in the winter, keep out wind, and resist condensation. By using the information contained on the label, builders and consumers can reliably compare one product with another, and make informed decisions about the windows, doors, and skylights they buy.
- NFRC adopted a new energy performance label in 1998. It lists the manufacturer, describes the product, provides a source for additional information, and includes ratings for one or more energy performance characteristics.
- NFRC rates all products in two standard sizes so that consumers and others can be sure they are comparing products of the same size. On the label, these two sizes are listed as "Res" and Non-Res."
NFRC Programs and Performance
- Products are rated and labeled through three NFRC programs which maintain the integrity and uniformity of the rating system.
- These programs are:
- The Laboratory Accreditation Program (LAP).
- The Certification Agency Program (CAP).
- The Products Certification Program (PCP).
- Many design factors determine a window's performance.
- NFRC does NOT:
- Distinguish between a "good" window and a "bad" window.
- Set minimum performance standards.
- Mandate performance levels.
- When a manufacturer decides to certify and label its products, it is committing itself to provide accurate, fair and reliable energy-related performance information. This helps consumers, architects, builders -- and the fenestration industry itself.
- U-factor measures how well a product prevents heat from escaping. The rate of heat loss is indicated in terms of the U-factor (U-value) of a window assembly. U-Factor ratings generally fall between 0.20 and 1.20. The insulating value is indicated by the R-value which is the inverse of the U-value. The lower the U-value, the greater a window's resistance to heat flow and the better its insulating value.
- Solar Heat Gain Coefficient:
- Solar Heat Gain Coefficient (SHGC) measures how well a product blocks heat caused by sunlight. The SHGC is the fraction of incident solar radiation admitted through a window, both admitted through a window, both directly transmitted, and absorbed and subsequently released inward. SHGC is expressed as a number between 0 and 1. The lower a window's solar heat gain coefficient, the less solar heat it transmits.
- Visible Transmittance:
- Visible Transmittance (VT) measures how much light comes through a product. The visible transmittance is an optical property that indicates the amount of visible light transmitted. VT is expressed as a number between 0 and 1. The higher the VT, the more light is transmitted.