Investing in Energy Star windows and doors can lead to long-term savings
Windows and doors ventilate air and natural light into the home. However, they are also where homes lose most of their energy efficiency. The good news is that they also present the best opportunity to save on heating and cooling costs by upgrading from a less expensive, single pane aluminum window to an energy-efficient vinyl alternative.
In the past ten years, the U.S. Department of Energy has done quite a bit to promote the Energy Star program. The Energy Star logo can be seen on dishwashers, HVAC systems, computers and, yes, even windows and doors. The logo by itself may signify an energy-efficient product, but what does that really mean to the homeowner in terms of dollars and cents?
The Efficient Windows Collaborative, operated by the University of Minnesota, publishes an independent web site with the sole purpose of differentiating window performance based on material type and glass package. The site is a real-time calculation tool that estimates energy use based on location and window configuration. This online tool makes it clear that a small investment in a more energy efficient, virtually maintenance-free vinyl window will truly pay dividends over the life of the home. In many cases, the investment pays for itself in less than two years. According to their site, an average family in San Antonio with single-pane aluminum windows will spend $1,000 to heat and cool their home each year. The same home with dual-pane vinyl windows containing Low-E glass with argon or krypton insulation would have annual heating and cooling costs of $475. By investing a few more dollars for vinyl, Energy Star compliant products, the homeowner can see an annual energy savings of more than 50 percent.
Performance variance in aluminum windows versus vinyl has more to do with the glass selection than the frame type. While vinyl is a much better insulator than aluminum, which conducts temperature very quickly, it is the Low-E glass that does most of the work by reflecting heat away from the home during summer and back into the home during winter. Argon gas insulation between the glass acts as an invisible blanket for advanced thermal efficiency.
For windows, Energy Star endorsements are based on two performance criteria: U-value (insulation properties) and shading coefficient. The solar heat gain coefficient measures how much heat transfers through a window. The lower the number, the less heat passes through. Reputable window or door manufacturers will have these numbers, frequently accompanied by the Energy Star logo, prominently displayed on the product’s NFRC label.
For more information about Energy Star performing windows and doors, check out the following Web sites:
