Thermal shades and draperies are very effective for insulating windows and improving comfort. Shades, draperies, or shutters are more effective if they are airtight or custom fitted, because they create a dead air space between themselves and the glass. The airtight seal also prevents warm, most indoor air from condensing on the window glass.
The energy efficiency of window coverings is measured in R-values, like insulation. The higher the R-value, the more it will protect your home from heat loss.
Benefits of adding efficient window coverings include:
Inefficient windows can add 10 to 25% to heating bills and up to a whopping 75% to summer air conditioning bills. Window coverings with a honeycomb or cellular construction can block up to 62% of the heat transfer through the window pane.
Standard window blinds have a R-1 value. Thermal or insulated window coverings can raise the R-value of a single-pane window from R-1 up to R-6, which will provide
Photo Courtesy of DOE/NREL, July 21, 2010- Light enters through louvered shades into the lobby and first floor of the new RSF (Research Support Facility) at NREL in Golden, CO
noticeably improved home comfort. A shading co-efficient is an important measurement for summer cooling, and it indicates the window covering’s ability to shade against heat gain. The lower the number, the more effective the shade will be in protecting your home from the summer sun.
Did you know that every kilowatt-hour (kWh) of electricity you avoid using saves over two pounds of carbon dioxide (CO2) from being released into the atmosphere?
Window treatments add another important benefit aside from insulation - UV protection. Ultra-violet rays can damage your home's interior, including furnishings, artwork and heirlooms, and floors.
Efficient window coverings include:
Photo Courtesy of DOE/NREL, University of Puerto Rico house
Cellular or honeycomb construction. The cells of a honeycomb shade actually trap the cold air, decreasing the intensity of the temperature as it enters the room. And this, in turn, helps minimize the amount of heat that's drawn toward your windows
Window quilts offer air and moisture-tight fabric along with 4-sided seals.
Draperies and Roman Shades can be thermally lined to increase efficiency
Hardwood shutters and wood blinds can improve the efficiency of your windows as well.
Questions to ask window covering installers:
If you decide to have window coverings custom-fitted for your home to maximize efficiency, make sure the installer has a thorough understanding of the energy efficiency properties described above. Determine the longevity of the company, and review the warranty information from the manufacturer and the installer to be sure you are covered both for product and installation defects.
References, licensing, insurance
It is always important to speak with previous customers, check with the Better Business Bureau and ask for verification of the necessary licensing and insurance requirements. Download a home improvement hiring checklist from the Federal Trade Commission (http://www.ftc.gov/bcp/edu/pubs/consumer/products/pro20.shtm).