While your windows to the world are necessary for light and to keep your home from looking and feeling cave-like, they are an energy drain. In the winter, inefficient windows can increase your heating costs 10–25 percent, and in the summer the sun’s intense rays can add as much as a whopping 75 percent to your AC bill.
Replacing your glassy panes is a good option because of the tax credits offered this year (30 percent of the cost, up to $1,500), but if that isn’t possible or if you’ve already replaced your windows and want even more energy efficiency, consider the way you cover your windows. The right coverings can add up to real savings, while still looking stylish. A suggestion: Before hanging up new window treatments, be sure to caulk and weatherstrip your windows for added energy efficiency and to keep out winter winds.
The right type
Your choice of curtains, blinds, shades, or other covering will most certainly depend on your personal preferences, but if you’re smart, you’ll also consider R-values when making your decision. The higher the R-value of the window covering, the more it will protect your window from heat loss. As a comparison, standard blinds have an R-value of 1.
Shades According to Energy Savers (U.S. Department of Energy), window shades can be one of the simplest and most effective window treatments for saving energy. Smart Energy Living estimates the R-values of these types of shades:
Honeycomb shades 2-4.8. According to Energy Savers, the dead air space within these shades provides insulation value but the shades provide only slight control of air infiltration.
Window quilts that offer air and moisture-tight fabric and 4-sided seal: 4.99.
Roman Shades 3-5, depending on the fabric, lining, and pleating. Roman shades can be thermally lined for greatest efficiency. Several layers of fabric contained within the shade can provide insulation.
Draperies As with Roman shades, these can be thermally lined to increase efficiency. R-values range from 3-5, with actual values dependent on the fabric, lining, and pleating. Energy Savers says that in winter, you can reduce heat loss about 10 percent; that’s why it’s important to close drapes every night. Keeping them open during the day, however, can let in sunlight and help warm your home.
Hardwood shutters and wood blinds These options offer R-values between 2.77 and 3.17.
Energy Savers recommends these purchasing and installation tips:
- Mount the shades as close to the glass as possible with the sides of the shade held close to the wall to make a sealed air space.
- For greatest shade efficiency, use a light, reflective color on one side and a dark color on the other side. Reverse the shades depending on the season. The light color should always face the warmest side (face out in the summer and toward the inside in the winter).
- Install draperies as close to the window as possible and let them fall to the window sill or floor. A cornice at the top also helps block air infiltration and offers greater efficiency. Using Velcro or magnetic tape to attach drapes to the wall at the sides and bottom may reduce heat loss up to 25 percent.
- Blinds and shutters are better at shading and preventing heat gain in the summer, so they are most effective when combined with draperies to help provide greater insulation.
- While not all draperies and shades list an R-value, look for clues on labels; terms such as blackout, light blocking, and thermal offer higher levels of insulation.
- Make your own inexpensive window solutions with instructions from Michigan State University Extension (includes a draft dodger, cornice, drapery seals, and more).
Read Super Energy Saver entry submitted by Blaine and Maricarol Hansen, members of Midland Power Cooperative, telling how they save energy with attractive window coverings.