How To Find Energy Efficient Windows In The Minneapolis & St. Paul Areas.

Energy Efficiency Among Windows In The Twin Cities Varies Wildly. Here Is What You Need To Know To Select The “Best Of The Best.”

Similar to how cars have a Miles Per Gallon rating, windows in Minneapolis, St. Paul, and the surrounding areas have an energy rating to determine how efficient they are.

Fortunately, it’s easy to determine a window’s energy efficiency—almost everything you need to know about its efficiency is found on the NFRC label attached to it. This label appears on all windows and is the only measurement accepted by the US Department of Energy’s Energy Star program.

The NFRC label has multiple numbers that indicate different efficiency measurements. The most important number for replacement windows in areas like St. Paul and Minneapolis is U-Factor. U-Factor measures the rate of heat loss in a window. The lower the U-Factor, the better the window insulates and keeps your home warm in the winter.

Here is what else you need to know about U-Factor:

  • Optimal U-Factor for windows in Minnesota is 0.30 or less. For superior energy efficiency, select windows with a U-Factor of 0.25 or less.
  • The average existing window (8+ years old) has an average U-Factor of 0.32 to .035, which is considered below average to poor.
  • You may save approximately 7% to 14% per year in energy costs for every 0.10 you lower the U-Factor of your windows.
  • Example: 0.20 windows could save you up to 15% per year in energy costs compared to 0.30 ones. (Examples and estimates assume average conditions and can vary depending on many factors.)

While U-Factor is the most essential rating for replacement windows in the Twin Cities, other ratings are important too. Here is what you need to know about each rating:

Solar Heat Gain Coefficient (SHGC): Measures the solar radiation a window admits. The rating is expressed in a number between 0 and 1, with lower numbers being better. Optimal SHGC in Minnesota depends on the situation. When air conditioning isn’t a concern, you can choose windows with a SHGC of 0.35-0.60, as winter solar heat can help offset the heating energy need. If cooling is a primary concern for you—and no shading options are available—choose windows with a SHGC less than 0.32.

Visible Transmittance (VT): Indicates the amount of visible light transmitted, and includes the impact of the frame that does not transmit any visible light. The rating is represented as a number between 0 and 1, with the higher number being better. Most windows measuring between 0.3 and 0.7. A high VT is desirable if you want a lot of daylight in your home.

Air Leakage: Indicated by the amount of air that passes through a square foot of window. Lower numbers are desirable. 0.1 is considered outstanding (and is also the lowest published rating on any label); 0.2 is good; 0.3 is average; 0.4 or higher is unacceptable.

Condensation Resistance: This measures a window’s ability to resist condensation on the interior. Higher numbers are desired, and are expressed between 1 and 100. Anything under 50 is unacceptable; 50 to 60 is good; 60 or more is very good.

Zen Windows Have Won Energy Star Awards!

We’re proud to announce that Zen Windows’ Manufacturer Partner, Soft-Lite Windows, won the National 2014, 2015, 2016, 2017 and 2018 ENERGY STAR Partner of the Year by the EPA. Soft-Lite manufactures all our windows, so we are very proud that they have been recognized for highly energy efficient design and construction of the windows.

Want the most energy efficient replacement vinyl windows in St. Paul, Minneapolis, and the surrounding areas? Click here to complete our 5-Minute Quote process. We’ll provide you with an accurate, ironclad quote by email within one business day—no in-home appointment necessary! Have more questions? Visit our Window Installation FAQ page to see the most commonly asked questions about window replacement.