24/7talk Interior Design

Create cozy rooms and cut at the same time energy costs when buying new Window Shades.

Understanding R-value

Building materials are assigned an R-value according to the product’s ability to resist heat movement.

• Window Properties

• Window frames are typically metal, wood or vinyl. The R-value of a metal frame can be 5 to 20 percent lower than a wood or vinyl frame window. A single layer of uncovered window glass has an R-value of 1.75. Advances in glass coatings and assembly methods are improving the energy performance of new windows, but a window’s age, quality of construction, and the condition of sashes, weather stripping and caulking will impact how much air infiltrates or escapes your home.

• Window square footage

• Windows make up 20 percent of the typical home exterior and 40 percent in contemporary construction. Numerous large, uncovered windows can break your energy budget when they’re on a cold north exposure in winter or a sun-saturated west wall in summer.

• Window Coverings

• Heat moves towards cold. In the winter it’s drawn to cold glass to escape your home (see illustration). In the summer outdoor heat moves toward the window of your air-conditioned home. The white exterior backing on all Hunter Douglas proprietary products reflects the sun. Using layers and cellular construction treatments at your windows can increase R-value by 1 to nearly 5 points. In extreme climates, that could save more dollars than you would spend to install windows with a higher energy efficiency.