PRL now has NFRC (National Fenestration Rating Council) Report #SIM140-048 available for our Max Slider Aluminum Sliding Glass Doors. The report is based on a 79″ x 79″ OX sliding door unit and evaluates the U-Factor, Solar Heat Gain and Visible Light Transmittance obtained using various insulated glass configurations.

For better understanding of what this report determines: U-Factor measures the heat from inside a room that can escape Lower number is better, Solar Heat Gain Coefficient (SHGC) measures outdoor heat entering a room Lower is better, Visible Transmittance (VT) refers to the amount of daylight entering through the window.

The best performance was obtained using ¼” SNX-6227 low e glass over ¼”solar grey glass with a ½” argon filled air spacer (.53 UF, .22 SHGC, .46 VT). Similar results with greater visible light transmittance can be obtained using clear glass in lieu of grey. For more information on PRL glass and aluminum products please feel free to call (800-433-7044) or visit our web site at