Understanding the NFRC Ratings on Replacement Windows

So many homeowners put emphasis on getting energy efficient replacement windows. But climates differ across the United States. A window that performs well in Texas will not have the same level of performance in Oregon. So before ordering replacement windows you want to make sure your window will help keep energy costs to a minimum. Fortunately the National Fenestration Rating Council (NFRC) has come up with a label. It helps guide consumers so they can find the perfect window for their home and climate. What do all those numbers and abbreviations mean? This small guide will help you out.

Energy Performance Testing, Certification, and Labeling
Windows and doors are the most vulnerable parts of your home. They can gain and lose heat through direct conduction, radiation of heat, and air leakage. The NFRC is a voluntary program. They test windows and doors, certifying and labeling them based on how well they prevent these types of gains and losses. Here are the ratings to look for in energy efficient replacement windows:

1. U-Factor
This rating is for the entire window, including the glazing, frame, and spacer material. Sometimes just the center-of-glass U-factor is also referenced, which is for the glazing alone. This measurement rates how well the product keeps heat or cool air trapped inside. Ratings range from 0.15 to 1.20. The lower the U-factor, the better the product insulates.

2. Solar Heat Gain Coefficient (SHGC)
If you are interested in energy efficient replacement windows, this is another important rating. It is similar to the U-Factor, but the SHGC specifically measures solar radiation. During different parts of the day certain rooms in your house will warm because of heat from the sun. A lower SHGC rating means the window works best to block this type of heat.

3. Air Leakage
No window or door is completely impervious to air leaks. This is because there will always be small cracks in the framing or window casings. However some replacement windows come close. Ratings go from 0.1 to 0.3. If you want a tight seal, letting no air out or in, then you want a low air leakage rating. You will experience fewer drafts in winter and less unwanted warm air in summer.

A Little About Other Ratings
The U-Factor, SHGC, and Air Leakage are not the only ratings you might see on your replacement windows. Energy labels can also include Visible Transmittance, Light to Solar Gains, and a Condensation Resistance rating. In turn these will tell you how much natural light gets into your home, the ratio between the SHGC and the VT, and how well your windows resist moisture. While these are also useful when comparing products, these ratings are not required. Many manufactures exclude them from the energy labels, but if they turn up you now know what they mean.

Find Energy Efficient Windows with EnergyGuard
If you are looking for efficient replacement windows in Tualatin, OR, go to the experts. Our name says it all! With over 40 years of experience we give you superior design and top quality products at a fair price. Call our office today at 503-554-5500 or drop by 516 E. 2nd St., Newberg, OR 97132 to set up your free, in-home consultation and estimate.