Building An Energy Efficient Sunroom
The good news is that you can have all of these great things sustainably and by working with contractors who specialize in Energy Star qualified sun rooms. ENERGY STAR qualified windows, doors, and skylights do more than just lower energy bills – they deliver more comfort, create less condensation, and protect furnishings and decorative accessories from sun damage better than conventional clear-glass double-paned alternatives. By lowering your energy use, these windows are also better for the environment: The less energy you use, the less air pollution power plants produce, and the lower your impact on carbon footprint.
You can learn a great deal about a sunroom’s energy performance by examining the window and door’s National Fenestration Rating Council (NFRC) label. Contained on that label is information about the U-Factor and Solar Heat Gain Coefficient performance. The NFRC is an independent, third-party certification organization with industry accepted standards for evaluating and certifying the energy performance of windows and doors. NFRC ratings for U-Factor and SHGC are used to judge the performance of windows and doors to determine qualification for ENERGY STAR. U-factor measures how well a product prevents heat from escaping. The rate of heat loss is indicated in terms of the U-factor (U-value) of a window assembly. U-Factor ratings generally fall between 0.20 and 1.20. The insulating value is indicated by the R-value which is the inverse of the U-value. The lower the U-value, the greater a window’s resistance to heat flow and the better its insulating value. Solar Heat Gain Coefficient (SHGC) measures how well a product blocks heat caused by sunlight. The SHGC is the fraction of incident solar radiation admitted through a window, both directly transmitted, and absorbed and subsequently released inward. SHGC is expressed as a number between 0 and 1. The lower a window’s solar heat gain coefficient, the less solar heat it transmits. Four Seasons Sunrooms is a national company that services the Chattanooga market and has an ENERGY STAR certified sun room program.
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This was a helpful article! I’ve always had a great interest in building a sunroom, but the energy efficiency factor has always held me back. I didn’t know how to tell how efficient any given window was, and frankly, never really think about the fact that there are different kinds that can allow for different efficiencies, so I’m glad that you pointed that out in this article! I’m glad that you included the U-value rating system of any specific window’s heat flow resistance. It’ll be a very helpful tool, should the dream day come when I’m able to build a sunroom!