How to Make Insulated Window Coverings
Whether coming in or going out, a substantial amount of heat moves through a window. Insulated window coverings can decrease heat loss in either direction. Some window treatments can do both, depending on the season, and some are specific to one-way insulation requirements. Knowing the type of insulation you need, and how to incorporate that into the window coverings you make, will result in a more comfortable room and reduced energy consumption.
Place a layer of lining between the decorator fabric and the window-side lining. Typically, black flannelette is used in this application, which also decreases the light-transferring capabilities of the treatment, resulting in insulation in both heat-loss directions.
Use blackout lining instead of regular lining. Blackout lining increases the R-value of the drapes by about 2 and helps prevent heat from leaving the room. (R-value is the resistance to heat loss of a substance. The higher the value, the less heat is lost. Most homes have insulation rated at an R of 12 to 24.) Blackout lining also insulates against heat from the sun entering the room in the summer.
Include a reflective-backed drapery lining as the final window-side layer in the treatment to deflect sun-source heat back out the window. Reflective-backed drapery lining is a lining with a reflective coating applied to one side, and is typically silver-colored.
Place vapor barrier between the decorator fabric and the first layer of the lining. Vapor barrier is any product that prevents vapor from crossing through to the adjacent material. This insulating layer reduces the amount of damp room air that can contact the cool window. Moist, room-temperature air against a cool window creates condensation and, in cool climates, can even result in ice buildup.
Include magnets in the side seams of the window treatments, attach a corresponding metal strip to the window frame or wall, and seal the window treatment to the wall or frame. Magnets are available individually or by the strip at hardware stores or in some fabric stores, and can be applied to the wall or fabric with two-sided tape (or the product may have a self-stick feature). The number and type of magnets you use is dependent on the thickness and style of your window covering. If using a strip of magnets, run the strip continuously down the side seam of the window treatment, attaching it per the manufacturer's instructions, and position a corresponding metal strip the same length down the wall or window frame.
Add a board-mounted valance above an inside-mounted window treatment, such as a Roman blind or manufactured shade. Ensure that the valance covers the top 4 or 5 inches of the window and add stationary side panels to cover the sides of the window frames. Used in conjunction with a Roman shade, and all components with blackout and interlining, this treatment can increase a window's heat-loss resistance from R-1 or R-2 up to R-15 or more.
Add pre-made blackout panels to the back of drapery. These panels attach to the drapery pins in the pleats of the drapes. They can be made of polyester, cotton, nylon, rayon, acrylic, to name a few materials, or a blend of fibers.
Linda Erlam started writing educational manuals in 1979. She also writes a biweekly newspaper column, "Design Dilemmas," in the "Lakeshore News" and has been published in "Design and Drapery Pro" magazine. Erlam is a graduate of the Sheffield School of Interior Design and is a practicing interior decorator and drapery workroom operator.