Windows & Doors

Windows and doors (also referred to as fenestration) are rated for energy efficiency. These ratings come in the form of U-factors, which is a measure of the equivalent insulation level, and the SHGC (Solar Heat Gain Coefficient), which measures the reflective value of the glass. As opposed to R-values, which utilize a numbering system from lower to higher with higher being better, U-factors and SHGC are the opposite. The lower number represented by the U-factor and SHGC measures greater resistance to heat, cold and solar radiation.

Acknowledgment: “The information, data, or work presented herein was funded in part by the Office of Energy Efficiency and Renewable Energy (EERE), U.S. Department of Energy, under Award Number DE-EE0006978, through the Energy Division of the Alabama Department of Economic and Community Affairs.”
Disclaimer: “The information, data, or work presented herein was funded in part by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.”