1-877-SWING CLEAN info@energyswingwindows.com FREQUENTLY ASKED QUESTIONS   4.  What’s the difference between R-value and U-value? R-VALUE R-Value is a rating given in construction to indicate how well a material insulates. The higher the number, the more insulation you are getting and the more money you are saving in energy costs.  Please be aware that a lot of window companies will say they have an R-Value of 25 on one component (say, just the frame of their window). However, you need to be sure to get the R-Value of the window as an entire unit, which is realistically between 2 and 4. U-VALUE U-Value is similar to R-Value, but there are two major differences. First, the U-Value rates an entire window or door unit, whereas the R-Value only measures specific materials. Second, the lower the U-Value, the more energy efficient your home will be (as compared to the higher R-Value being more energy efficient). This difference in scale exists because R-Value rates how much heat is retained, whereas U-Value rates how much heat is lost. Energy Swing windows meet Energy Star efficiency standards with a U-Value of .3.   Submit your questions to Steve Rennekamp, who has 40 years of experience in windows & doors. Back to Questions 3245 Miracle Drive Murrysville, PA 15668 724-387-2991 PA Contractor ID PA001856