How Do Window Shades Work?

Controlling Room Light

• Shades control light in a room by allowing you to adjust the collective position of the window treatment's slats or fabric extensions. By pulling on a cord or sliding a rod across a track, you can leave the shades at a fully open position to allow sunlight to enter the room unabated, or you can adjust the slat/ fabric extension position to eliminate sunlight altogether. If you desire varying amounts of light throughout the day, you can easily move the shade position to suit your needs as the sun moves.

Keeping Heat Out

• During the summer months, your shades can actually keep your home cooler by reflecting sunlight hitting your windows. According to Green Building Advisor's website, window shades reflect light energy from your home that would otherwise convert into heat energy once inside your property. This allows you to keep your home cooler and reduce the need to run your air conditioner, which lowers your utility bill. How much light your shades reflect depends on the color as well as the position of the shades. You need to close your shades to reflect sunlight from your home. Silver-colored drapes reflect the most sunlight, whereas black shades absorb the most.

Keeping the Heat In

• Just as shades can keep your home cool during the summer, these window treatments can also prevent warm air from escaping during the winter. According to the Green Building Advisor's website, interior shades can increase thermal comfort in a room by as much as 5 degrees Fahrenheit. When purchasing shades for your home, examine the manufacturer's thermal performance certification on the product packaging. A rating of R-8 is the best possible, though this rating is achievable only if the shades produce an airtight seal around your windows.

Windows Must Cooperate

• Window shades can achieve optimal performance only if the seals and glass panes in your windows aren't leaking air on a constant basis. Poorly insulated windows, broken glass panes or old seals can promote heat loss during the winter and allow hot air to creep into your home during the summer. A licensed professional should examine your windows to determine whether you need to replace the glass or install entirely new structures.