How to Read a Replacement Window Label

Each replacement window that you select for your home has a label from the National Fenestration Rating Council (NFRC) that provides ratings of energy performance. The NFRC is a non-profit organization that “administers the only uniform, independent rating and labeling system for the energy performance of windows, doors, skylights, and attachments.”   (www.nfrc.org)

1)      U-Factor

This measures how well a window is insulated and how energy-efficient it is. This includes the window frame, spacer and glazing. The lower the U-factor, the more energy-efficient the window is. For example, a U-factor of .30 is the minimum requirement for a window to be considered efficient. Anything above .30 is not efficient and will cost you more money in the long run. For instance, our windows have a U-factor of .25, one of the lowest and most energy-efficient rated windows on the market.

2)      Solar Heat Gain Coefficient

The (SHGC) measures how well the window blocks heat caused by sunlight from entering your home. This number is between 0 and 1, and the lower the SHGC, the less heat will filter into your home.

3)      Visible Transmittance

(VT) measures how much light is allowed to enter through the window and is expressed between 0 and 1. The higher the VT number, the more light will be able to filter through the replacement window.

4)      Air Leakage

The lower the Air Leakage rating, the less air flows through the openings of the replacement window assembly. This is not always shown.

5)      Condensation Resistance

The CR measures how well the replacement window repels condensation forming on its interior panels. The CR is indicated by a number between 0 and 100, and the higher the rating, the better the window is considered at repelling condensation. This also is not always shown on the label.

6)      C.E.C Air Infiltration Standards

CEC stands for the California Energy Commission, the state’s energy policy agency that through appliance and building standards, promotes energy-efficiency.

7)      WDMA

This stands for Window & Door Manufacturers Association and defines the standards of superiority for the window, door and skylight industry. The WDMA provides excellent resources and professional programs to help businesses in the industry provide greater value to consumers.

8)      Hallmark Certified

The WDMA Hallmark is considered a mark of superior work among contractors and architects and is accepted throughout the industry.

 

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