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How to Read a Window Energy Efficiency Label

How to Read a Window Energy Efficiency Label

Window energy efficiency is an abstract notion for most people. It’s hard to know how energy efficient your window is. The good news is that you can understand this better by learning to read the energy efficiency label that exists on all new windows. After you read this piece, you’ll be able to get new windows that are incredibly energy-efficient, based on what the label says.

The National Fenestration Rating Council has created an energy efficiency label for windows, which serves as a single point of reference for both energy installment companies and homeowners to understand how energy efficient a window is

Window Energy Efficiency Label Explained

To understand the label, we need to understand all the numbers and codes that exist on the label. Let’s see:

  • In the upper left corner is the NFRC certified stamp that says the window’s manufacturer was licensed by the National Fenestration Ratings Council (NFRC). 
  • Under the label that says Energy Performance Ratings are two numbers: 1) To the left is the U-factor that measures how much the window keeps the heat from escaping a room. The range of the factor goes from 0.20 to 1.20, and the lower the number, the better the window is at keeping the heat inside. 2) To the right is the Solar Heat Gain Coefficient that measures how well the window resists heat gain. The range goes from 0 to 1, and the lower the number, the less money you’ll spend on cooling. 
  • Under the lower label that says Additional Performance Ratings are also two numbers: 1) To the left is the Visible Transmittance number that measures how well the window is designed to let sunlight inside. The number ranges from 0 to 1, and the higher the number, the more light the window lets in the house. 2) To the right is the Air Leakage number that measures how much air enters the room through the window. It ranges from 0.1 to 0.3, and the lower the number, the less draft you’ll feel.

The rest of what you see on the label is information like the name of the product, the manufacturer, etc. 

We at 1-800-HANSONS install only windows that are of the highest quality and of the highest energy efficiency as well. If you want to know more, feel free to contact us and inquire about our prices and our methods.

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