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A Minnesota Homeowner’s Guide To Understanding Energy-Efficient Window Labels

Your windows lose up to 25% of your home’s energy every year. This means that windows waste more energy than your doors, walls, and any other surface in your home. Save on your heating costs during Minnesota’s notoriously frigid winters (and reduce your summer cooling costs) by installing energy-efficient windows. Unfortunately, many homeowners find the definitions on window labels confusing. If you are on the market for energy-efficient windows, here is what you need to know to navigate your many options.

3 Steps to Choosing Energy-Efficient Windows

Step 1: Look for the Energy Star Label

The ubiquitous Energy Star icon means that the U.S. Environmental Protection Agency has tested and found the windows to be energy efficient. 

Step 2: Know Your National Fenestration Rating Council (NFRC) Climate

Every single Energy Star-rated window also has a label on it telling you its NFRC rating.

A window that is energy efficient in a warm state like Hawaii would perform poorly in a climate like Minnesota. That is where the NFRC rating comes in. It explains the exact performance of the window in Minnesota’s winters and summers. 

Minnesota is a “Northern Climate” in the NFRC’s index.

Step 3: Check the Window’s NFRC Performance

The NFRC label on your energy-efficient window will display four things:

  • U-Factor: This is important for the winter, and tells you how efficient the window will be at keeping heat inside your home
  • Solar Heat Gain Coefficient: This is critical in the summer, and tells you how well the window blocks out unwanted heat from the sun
  • Visible Transmittance: This tells you how well the window lets your natural light
  • Air Leakage: As its name suggests, this identification lets you know how drafty a window can be

For the best energy conservation, you want:

  • A U-Factor that is as low as possible (it will range from 0.20 to 1.20)
  • A solar heat gain coefficient that is as low as possible (it will range from 0 to 1)
  • A visible transmittance rating that is as high as possible (it will range from 0 to 1)
  • An air leakage rating that is below 0.3

Some windows may display the numbers for numerous climates. For Minnesota homes, look for the designation next to “Northern Climate.”

If you still find energy-efficient labels confusing or misleading, reach out to the experts at Minnesota Heating and Air Conditioning. With more than 30 years in the business, we can help you find the best windows for your home and your lifestyle. Contact us today for more information!