January 29, 2001
Contact: Leona K. Hawks, 435-797-1529
Writer: Donna Falkenborg, 435-797-1363, donnaf@ext.usu.edu


LOGAN — “With the price of fuel skyrocketing, now is the time to think about energy-saving projects around the house, and the best place to start is with your windows,” advises Leona K. Hawks, Utah State University Extension housing specialist.

Hawks says that in an otherwise well-insulated home, single pane windows account for about 35 percent of the home’s winter heat loss. Even with storm or double windows, heat flow through windows is 10 times greater than the amount of heat loss through well-insulated walls.

“But you don’t have to board up your windows to save energy,” Hawks says. “There are many potential energy conserving indoor window treatments.” She suggests the following:

  • Window Shades. The familiar roller shade can make a considerable difference in winter as well as summer energy savings. They can save one quarter to one third of the indoor heat lost through windows in the winter. The key to maximum energy savings is mounting the shade inside the window frame with no more than one-fourth inch clearance on the sides.
  • Lambrequin: This is a wooden frame that surrounds the window. It may be painted, papered or covered with fabric. The lambrequin is used to reduce air leaks and the movement of the air into and out of the sides and top of the window area.
  • Covered Insulation Panels: This is one of the most energy efficient window treatments you can use. The amount of heat lost through the window is reduced in proportion to the insulating value of the material found within the covered panel. Similar to the other window treatments, the key to maximum insulation is a tight fit within the window frame. The trapped air space between the window and the panel adds important insulation value.
  • Insulated Roman Shades: These are made of batting and tightly woven fabric front and back. The insulation value is dependent on the materials used to make the shades. They are designed to fold when not in use.
  • Draperies: This is the most common type of window treatment. They are sometimes called pinch or French pleated drapery. For these to be most efficient they must be hung with a closed-top cornice, overlapped in the center, made of tight woven fabric, sealed to the wall on the sides and the bottom should come in contact with the window sill or the floor.
  • Closed-top Cornice: When an interior window is closed with draperies but not sealed at the top and bottom, warm air moves between the window treatment and the glass creating a wind tunnel effect. The warm air enters the top, cools as it falls between the glass and the window treatment and then leaves through the bottom as cold air. The closed-top cornice helps reduce these convection currents.
  • Curtain Liners: The simple addition of a liner of tightly woven fabric can aid insulation by forming an air pocket between the liner and curtain.