Taking the Window Pain out of Energy Bills
Windows can add a pleasing appeal to a home—they let in natural light, offer a view to the outdoors and add to a home’s overall appearance, but they can also be the culprits of costly air leaks. During the winter, many homeowners explain how they feel noticeably cold air near their windows. There can be several reasons for this. First, windows offer the smallest amount of protection from the weather conditions outside. If you think about it, your home’s walls are, on average, eight inches to one foot thick, and consist of wood, insulation and sheetrock, offering you several layers of protection from the elements. A window, on the other hand, does not offer much depth, or significant temperature resistant surface between you and Mother Nature.
Additionally, many people may feel cool air concentrated around windows due to drafts caused by gaps. These gaps can be large enough for you to see or so small, you don’t realize they exist. So what can you do to take the “pain” out of windows that allow outside air infiltration? One option is simply caulking around the window frame. Caulking windowsill gaps is a fast and inexpensive way to keep cold air out during the winter.
Another option to block the cold is to install insulated, or black out, curtains. These curtains aid by adding an extra layer of material against cold air, which can reduce heat loss through the window by as much as 25 percent. Throughout the winter, insulated curtains should be open during sunny days to allow the sun’s radiant heat to help warm the house and closed on cloudy days and at night to help keep the heat inside.
Many people often ask if replacing their windows is a good investment since they can be costly to upgrade. On average, it can take three to seven years or longer to receive a payback.
But if you do decide to replace your home’s windows, there are some features you should look for. Double panes (or two sheets of glass) offer a thicker barrier for your home from the outside temperatures than do single panes. Double-paned windows contain a type of gas in between the panes as well as a coating on the glass. The gas between the panes is heavier than air and reduces the movement of air. Low emissive coatings on the glass (Low-e) are used to block the heat from the sun and are another beneficial feature to request. The frame of the window also plays a role and should be constructed of either vinyl or fiberglass, both of which offer a higher value of energy efficiency than wood-framed windows, which can decay over time, allowing air leaks.
Also, look for Energy Star-rated energy efficient windows. These windows are double-paned and include two numbers showing the efficiency of that particular window: the U-factor and the Solar Heat Gain coefficient. The U-factor measures how easily heat can flow through the window and should be .35 or less, the lower the number, the more energy efficient is the window. The Solar Heat Gain Coefficient, which should be .30 or below, depicts the window’s ability to absorb heat from the sun, and is more important during Alabama’s long summer months.