Homeowners have long installed awnings as a way to shade windows, improve the appearance of their homes or provide a shaded area to sit outside on a warm, sunny afternoon. But awnings also can have a positive affect on your energy bill, according to a new study conducted by the Center for Sustainable Building Research at the University of Minnesota, in conjunction with the Professional Awning Manufacturers Association (PAMA).

The study found that in a cooler climate, such as Seattle, installing window awnings can reduce home cooling requirements by as much as 80 percent. And in a warmer climate, such as Sacramento, awnings can reduce cooling requirements by as much as 48 percent. The amount of energy saved varies, and depends on the location of the home, the number of windows, the orientation of the windows (east, south, west) and the type of glass in the windows.

The study measured the impact of awnings in seven U.S. cities, including Albuquerque, Boston, Minneapolis, Phoenix, Sacramento, Seattle and St. Louis. There were significant savings in all cities for all window orientations.

For a home in Phoenix, a warm climate, window awnings can reduce the use of home cooling energy by as much as 26 percent, compared to a home with unshaded windows, the study found. In St. Louis, a mixed climate, awnings can reduce the use of cooling energy by as much as 23 percent, while in Boston, a cold climate, awnings can reduce the need for cooling energy by as much as 33 percent.

"Depending on the region, awnings can save homeowners more than $100 annually [in energy costs]," says Michelle Sahlin, managing director of PAMA. She also notes that "when homeowners reduce their need for energy, there is less demand at the time of peak usage, resulting in overall savings to utility companies and the public."

The study measured energy performance for a typical new home of 2,000 square feet, with 300 square feet of window area. To view charts of specific energy savings in various cities or to locate a local awnings retailer or installer, visit the Awnings Today website at http://www.awningstoday.com.