Saving energy with new windows and green design
March 20, 2012
When it comes to energy efficiency, many Americans leap into homes that are doomed from the start. As utility bills continue to rise, some chase after costly retrofits or find ways to conserve energy. Green living is relatively new and our aging housing stock was never designed to adapt to this emerging technology.
Passive solar design is one of the best ways to create a home that conserves energy, and green strategies begin when the home is but a sketch on paper. The key to passive solar design, according to the U.S. Department of Energy, lies in the home's initial orientation and its ability to work in harmony with the local climate. New homes should be planned through conversations between homeowner and architect, with this goal in mind. Existing homes can also be adapted according to efficient passive-use principles, or upgraded with energy-efficient new windows.
New windows, new directions in passive heating
Orientation can spell the difference between building a power guzzler or an energy efficient home. The California Energy Commission reports that 30 percent of a home's heating and cooling evaporates out of leaky windows and doors. That makes home orientation and the quality of your windows especially important in home design.
The Efficient Windows Collaborative confirms that solar orientation has a significant impact on heating and cooling costs. If you're shopping for or building a home in North America, the accepted formula suggests that the south wall should face within 30 degrees of true south, and the length of the home should run east and west.
Homepower Magazine reports that the sun streaming through south-facing windows provides between 20 percent and 80 percent of the heat you need in the winter. That's a big range, but you can improve your percentage.
Ideally, windows on the south-facing side should take up from 8 to 12 percent of the total square footage of the home. In summer, you can cut back on unwanted solar heat gain through your south-facing windows by using awnings or roof overhangs. The rooms that get the most use in winter should be located on the south-facing side of the home.
When you're buying windows, look for low U-factor-rated products if you live in a cold climate. Choosing the right glass for new windows should be a top priority. New windows with low solar heat gain coefficient ratings are generally a good choice if you live in the South. Double-pane or triple-pane gas-filled windows offer year-round energy efficiency for most of the country.
Window treatments save energy
Don't overlook window treatments in your plan. Insulated shutters or blinds can keep wanted heat in the home during the winter. Depending on the seasons, you may want easy-to-swap sets of drapes and curtains.
On another note, Homepower Magazine recommends that you choose sun tubes -- rather than skylights -- in rooms that have no windows or are too dark. Skylights, the magazine says, are pipelines for unwanted summer heat and cannot be adequately shaded.
In an era when every penny of your utility savings counts, it's best to beat the devil by design.