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ENERGY STAR® vs. NFRC: What Do The Labels Mean?

Replacement windows come with different ratings and certifications. In fact, window installation companies utilize the labels to signify that the products they offer are high-performing and of superior quality. When considering new windows or doors, there are two labels that you should look for: the National Fenestration Rating Council (NFRC) and ENERGY STAR®. To know more about what these labels mean, keep reading.

What the NFRC Label Means

NFRC is an industry-recognized certifying body for windows and doors. The nonprofit organization aims to inform consumers with energy performance ratings and other useful information about windows, doors, and skylights. NFRC labels provide performance ratings in five categories:

1. U-Factor

This measures the rate of heat transfer, therefore indicating how well a window or door insulates. U-factor values range from 0.20 to 1.20. You want to look for a product with the lowest number available because it means that it has superior insulating properties.

2. Solar Heat Gain Coefficient (SHGC)

This tells you how well the product blocks heat from the sunlight. The direct measurement relies on the fraction of solar energy transmitted. The values typically range from 0 to 1. Energy-efficient windows have lower numbers because it means less heat can pass through them.

3. Visible Transmittance

This measures the amount of light that passes through the window. The values range from 0 to 1, similar to SHGC. The lower the number, the less amount of light your room will see; a higher number means the space will be brighter.

4. Air Leakage (AL)

This measures the rate at which air passes through the joints in the window. The lower the number means the more airtight your window is. Industry standards and building codes usually require 0.3 (expressed cubic feet per minute per square foot of window) for AL.

5. Condensation Resistance

This category is scored on a scale from 0 to 100. The higher the number is, the less water buildup the windows allow.

What the ENERGY STAR Label Means

ENERGY STAR products are tested, certified, and verified by NFRC. The organization does not identify between “good” or “bad” windows or set minimum performance standards. However, with the ENERGY STAR label, the consumers can easily weigh their options and identify which products have superior energy performance. ENERGY STAR windows or doors use less energy, therefore reducing both your monthly utility bills and harmful emissions from power plants.

At Renewal by Andersen® of Memphis, we believe that every home deserves the best. We offer ENERGY STAR-certified windows and doors to ensure indoor air quality and overall comfort for homeowners. Call us at (901) 979-4460 or fill out our contact form to schedule a free consultation.


"We were very pleased with the process. Our windows are beautiful, and we are very happy we made the decision to choose Renewal by Andersen!"

Scott | Memphis, TN
November 10

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