We put together the information below to help you make an informed decision but if you need more help or info on Rebates & Tax Credits you can visit http://energy.gov/energysaver/energy-efficient-windows
Choosing a Window Benefits of Efficient Windows
Low-E - Low emissivity or low-e glass is a coating that increases a window or door's ability to diminish heat transfer, thus saving heating and cooling costs. In addition to energy savings, Low-E also effectively reduces the amount of transmitted ultraviolet light which can damage carpets, fabrics, and drapes.
Low-E/Argon Gas Low-E Glass and Argon gas between the glass for superior thermal efficiency. Argon gas is much heavier than air, making it more difficult for warm or cold air to pass through. This glazing choice will meet or exceed most local building code requirements and provides ENERGY STAR® qualified performance.
U-Factor The rate of heat loss is indicated in terms of the U-factor (U-value) of a window assembly. The lower the U-factor, the greater a window's resistance to heat flow and the better its insulating properties
R-value, U-value or U-factor – R-value indicates the resistance to heat flow through a window. U-value, the inverse of R-value, indicates a window’s tendency to transfer heat. Both R-value and U-value are measures of heat flow through a window. The higher a window or doors R-value,the more energy that is saved.
Plastics are relative newcomers as window frame materials in North America. Vinyl, also known as polyvinyl chloride(PVC), is a very versatile plastic with good insulating value. Vinyl window frames do not require painting and have good moisture resistance. Because the color goes all the way through, there is no finish coat that can be damaged or deteriorate over time—the surface is therefore maintenance-free. Some vinyl window manufacturers are now offering surface treatments like laminates (wood veneer, paintable/stainable, maintenance free) and coatings. These products increase color selection and surface appearance options. Recent advances have improved dimensional stability and resistance to degradation from sunlight and temperature extremes.
In terms of thermal performance, vinyl frames are comparable with wood, while there are minor differences, depending on the frame construction. Small hollow chambers within the frame reduces convection exchange, as does adding an insulating material.
A variation of the wood-framed window is to clad the exterior face of the frame with either vinyl or aluminum, creating a permanent weather-resistant surface. Clad frames thus have lower maintenance requirements, while retaining the attractive wood finish on the interior. While vinyl and enameled metal claddings offer much longer protection to wood frames, they are generally available in a limited number of colors.
The traditional window frame material is wood, because of its availability and ease of milling into the complex shapes required to make windows. Wood is favored in many residential applications because of its appearance and traditional place in house design. From a thermal point of view, wood-framed windows perform well. Wood is not intrinsically the most durable window frame material, because of its susceptibility to rot, but well-built and well-maintained wood windows can have a very long life. Paint protects the exterior surface and allows an easy change in color schemes.
Many people put up storm windows in the winter, and they do help. But storm windows are typically fairly leaky. If you are deciding whether to buy storm windows or replace your existing ones, you're probably better off putting your money into new double-pane windows.
Energy & Cost Savings: Energy efficient windows can substantially reduce the costs associated with heating and cooling. Creating savings in both heating and cooling climates.
Lower HVAC Costs: High-performance windows not only provide reduced annual heating and cooling bills, they also reduce the peak heating and cooling loads The use of high performance windows can help in reducing HVAC equipment sizing.
Improved Comfort: Cold glass can create uncomfortable drafts as air next to the window is cooled and drops to the floor. Also, strong direct sunlight through window onto people and interior surfaces can cause overheating and discomfort. High performance windows, in different climates, help make home more comfortable.
Reduced Condensation: High-performance windows create warmer interior glass surfaces, reducing frost and condensation.
Increased Light and view are two of the fundamental attributes of a window. High performance windows help to reduce unwanted heat gain while still allowing light to enter into your home.
Reduced Fading of Materials: Materials such as carpet, fabrics, paper, artwork, paints, and wood may fade upon exposure to sunlight.
The Importance of Quality Window Installation Quite simply, windows are only as good as their installation. Proper installation will: