What is R-Value?

09 Mar What is R-Value?

Building materials are assigned an R-value according to the product’s capacity to withstand heat movement.  The higher the R-value the better it insulates your home.  Most windows have an R-value of 0.9 to 3.0 and can be responsible for 40 to 70 percent of heat or cold transfer for an entire home.  The heat loss or gain at your home’s windows is effected by the following:

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.  Improvements in glass coatings and assembly methods are increasing 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 gets into or escapes your home.

Window square footage

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

Window coverings

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

To find out which window coverings will work best in you home, contact Premier Shutters and Blinds.