You can choose window treatments or coverings not only for decoration but also for saving energy. Window treatments can reduce energy use in your home, and are less expensive than purchasing new, energy-efficient windows. Some carefully selected window treatments can reduce heat loss in the winter and heat gain in the summer. 

BLINDS

Window blinds, vertical or horizontal slat-type, are more effective at reducing summer heat gain than winter heat loss. Because of the numerous openings between the slats, it’s difficult to control heat loss through interior window blinds, but the slats offer flexibility in the summer. Unlike shades, you can adjust the slats to control light and ventilation. For example, when completely closed and lowered on a sunny window, highly reflective blinds can reduce heat gain by around 45%. They can also be adjusted to block and reflect direct sunlight onto a light-colored ceiling. A light-colored ceiling will diffuse the light without much heat or glare.

SHADES

When properly installed, window shades can be one of the simplest and most effective window treatments for saving energy. Shades should be mounted as close to the glass as possible with the sides of the shade held close to the wall to establish a sealed air space. You should lower shades on sunlit windows in the summer. Shades on the south side of a house should be raised in the winter during the day, then lowered during the night.

For greater efficiency, use dual shades—highly reflective (white) on one side and heat absorbing (dark) on the other side—that can be reversed with the seasons. The reflective surface should always face the warmest side—outward during the cooling season and inward during the heating season, and they need to be drawn all day to be effective.

Quilted roller shades and some types of Roman shades feature several layers of fiber batting and sealed edges. These shades act as both insulation and air barrier, and control air infiltration more effectively than other soft window treatments.