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 2005. It lists the manufacturer, describes the product, provides a source for additional information, and includes ratings for one or more energy performance characteristics.

NOTE: All energy performance values on the label represent the rating of windows/doors as whole systems (glazing and frame).

The information contained on the label is also available in the NFRC's online Certified Products Directory.

U-Factor

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 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 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 in the house.

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.

Air Leakage*

Air Leakage (AL) is indicated by an air leakage rating expressed as the equivalent cubic feet of air passing through a square foot of window area (cfm/sq ft). Heat loss and gain occur by infiltration through cracks in the window assembly. The lower the AL, the less air will pass through cracks in the window assembly.

Condensation Resistance*

Condensation Resistance (CR) measures the ability of a product to resist the formation of condensation on the interior surface of that product. The higher the CR rating, the better that product is at resisting condensation formation. While this rating cannot predict condensation, it can provide a credible method of comparing the potential of various products for condensation formation. CR is expressed as a number between 0 and 100.

Energy-Saving Window Design

Frame Building Supplies

Below are the  energy-efficient building materials used for ENERGY STAR qualified windows. Ja-Mar Exteriors will asses your window framing needs and choose the most efficient material.

Wood provides a quality seal and blends with the natural landscape present around many traditional residences.

Vinyl stands up to harsh weather conditions without breaking down--creating a long-lasting seal. Vinyl is often used in conjunction with other materials to achieve a unique style.

Composite building materials produce strong frames that require almost zero maintenance and will not allow air to evacuate around the edges of the window.

Fiberglass is a lightweight wear-resistant material ideal for window frames. Hollow pieces of fiberglass may be reinforced with additional insulation.

Find out more about how energy-saving windows are designed from the Efficient Windows Collaborative.

Energy-Saving Door Design