Coastal Virginia’s Window & Door Company

How to Read a Window Energy Performance Label

| CVP Windows & Doors |

Want to window shop like a pro? It’s as easy as learning how to read a window Energy Performance Label. In the same way a nutrition label can help you decide which foods to eat, the energy performance label can help you find the best option among several replacement window types and manufacturers.

Finding the Best Window Energy Performance Ratings

Before you place an order for new replacement windows, take a look at the Energy Performance Label.

1. Look for the ENERGY STAR logo

The ENERGY STAR logo means that the window meets U.S. governmental standards for energy efficiency in your region. Buying ENERGY STAR windows will save you money and protect the environment by cutting back on wasted energy.

In order to be ENERGY STAR certified, the window system must be independently tested, certified, and verified by the National Fenestration Rating Council, or NFRC for short.

The ENERGY STAR logo certifies that a window is energy-efficient. But, that’s just the beginning. Window performance varies widely depending on materials used, construction, and window type. To truly understand these differences, you need the ratings on the NFRC label.

2. Check out the Energy Performance Ratings

  • The U-Factor Rating indicates how well the window will insulate your home and prevent heat from escaping. The lower the number, the better the performance.

    For reference, the ENERGY STAR recommended range is between 0.25 and 1.25. Our CVP Double-Hung DH55 window with LowE 366, argon-filled glass carries a U-Factor of 0.30.

  • The Solar Heat Gain Coefficient indicates how well the window resists heat from the sun. The lower the number, the better the window is able to block radiant heat. In our hot, humid Coastal Virginia climate, a low SHGC is important to keep your home cool.

    For reference, the ENERGY STAR recommended range is 0.25 – 0.80. Our CVP Double-Hung DH55 window with LowE 366, argon-filled glass carries an SHGC of 0.19.

3. Understand the Additional Performance Ratings

  • The Visible Transmittance rating indicates how much visible light passes through the window glass (or glazing). For reference, the ENERGY STAR average range is 0.20 – 0.80. Our CVP Double-Hung DH55 window with LowE 366 glass is well within range with a Visual Transmittance of 0.48.

  • Air Leakage indicates how much air passes through the joints of the windows. For reference, the industry standard recommended by ENERGY STAR is 0.3 cf·m/ft². All CVP windows meet or exceed this standard.

Now, don’t overlook the installation…

Buying the best windows won’t guarantee that you’ll achieve a more beautiful, comfortable, and energy-efficient home. To see those benefits, your windows also need to be properly installed. 

Our Free Consultation Helps You Understand Window Energy Performance

At CVP, we pride ourselves on the quality of our product, our installations, and our commitment to “always do the right thing.” We look for solutions which not only make your home look great but also protect the long term value of your home. Choosing the right window and proper installation is essential to achieving desired results.

If you’re looking for the best windows for your home, call for a free estimate. Our sales and executive team has a combined 125 years of experience in the homebuilding industry. We’re happy to share our expertise. Give us a call at 1-757-887-3194 or request your free estimate.

CVP Windows & Doors

Written By
CVP Windows & Doors

CVP Windows & Doors
For 20 years and counting, CVP Windows & Doors has been the only company in Hampton Roads, Virginia, to manufacture, deliver, and install custom vinyl windows and doors. We’re proud to say that every window and door we sell is proudly made in the USA.
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