How the NFRC Ratings Help you Choose Replacement Windows

Purchasing new windows is a significant investment. These windows contribute to the comfort, security, and efficiency of a home. And choosing replacement windows complex purchase. There are a lot of factors to consider before making a final decision. Few homeowners really understand one of the keys to finding the right replacement windows in San Marcos, CA—the NFRC energy labels.   

The National Fenestration Rating Council (NFRC) is an independent, nonprofit organization that tests windows objectively. Their labels provide ratings so homeowners can better compare products and make informed decisions about important features like insulation, heat gains, air leaks, and condensation. Here are what the parts of the NFRC label tell you:   


This rating shows how well the window blocks non-solar heat transmission. It is the inverse of the R-value. Ratings range from 0.2 to 1.2. Lower numbers mean even better insulation from the outside in and the inside out. Acceptable U-factor ratings for our area generally fall between 0.4 and 0.5.   

Solar Heat Gain Coefficient 

The SHGC shows how well a window protects against radiant heat from the sun. This rating is especially important for windows you know will see a lot of sun exposure. Ratings measure between 0 and 1, and again, lower numbers mean the window blocks more heat. This is important in California where sunny days are common.   

Visible Transmittance 

This rating is not about energy savings, but light filtering through your windows. This is important when deciding how much natural light you want in each room. The rating is between 0 and 1, and the higher numbers allow more light to come through. If you are a fan of daylighting you want something around 0.7. If you want to limit glare in a television room it is better to find something around 0.3.   

Air Leakage 

No product will offer you a perfect seal. Even non-operable picture windows will have some air passing through, though the amount is minimal. As the name suggests, this rating shows how much air can be gained and lost through the cracks in the assembly. Measurements range from 0.1 to 0.3 cubic feet per minute per square foot. The lower ratings mean the windows are more airtight.   

Condensation Resistance 

Moisture buildup on the inside of windows isn’t uncommon and often has more to do with humidity on than the windows themselves. Yet there is a condensation rating you can use. These numbers run from 1 to 100 and the higher numbers mean the products have a better condensation resistance.   

If you still have questions about decoding the energy ratings on replacement windows in San Marcos, CA you should contact Pelican Replacement Windows. Our experts can walk you through all the basics of getting new windows, but also help you pin down the right types of windows for your home. They can also help you match the right style, material, and upgrades to your budget. Call (760) 598-6422 to talk to one of our experts today. Or visit 2210 La Mirada Dr., Vista, CA 92081.  

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