You’ve likely heard of this term before, now you probably what do understand what does it mean?

To put it simply, R-Value sis a measure of a given material’s resistance to heat flow and how well it resists heat gain or loss. This means, the higher the R-Value you have, the better insulation it will provide for your home.

R-Value and Windows

Your windows themselves have an R-Value assigned to them. A typical window has an R-Value anywhere from .9 to 3.0. To put this in a bit of perspective, a modern home’s insulation has an R-Value in the low 40s.

Thermal Imaging & R-Value

The photos that were taken above were of a window in Vermont. A FLIR IR camera was used to take them. You can see that the temperature of the glass was at 28 degrees at 8pm when it didn’t have a shade. Once the shade was down, the temperature rose to 61.5 degrees at 8pm. Once the side tracks were in place, the temperature rose to 64. Degrees at 9:13 pm. The shades that were used in the photos were our double cell black out (link to product page) fabric.

Many Factors Influence the R-Value of Your Windows:

  • The installation process
  • Type of material that was used for glazing
  • How many layers of glass there are
  • The amount of air space between the glass layers

R-Value and Your Window Treatments

Windows are one of the greatest sources of wasted energy in your home. Heat always moves from warm to cold areas in your home. During the winter, warm air from inside your home is trying to escape through your windows. In the summertime, the suns heats up your home and its rays flow through your windows. In the end, you pay for all of this extra energy consumption.

To reduce your energy bills, use cellular window treatments. For these treatments to be effective, the treatment must trap air between your shade or blind and the glass on the window. Our cellular shade products act as a barrier and save you money in the long run.

How do other types of window treatments compare to Cellular Shades? For More info see our R-value comparison charts....

Compare R-Value by Fabric TypeShade Only Single Pane (+1)Double Pane (+1.8)Triple Pane (+3.5)
Double Cell Light Filtering  2.8 3.8 4.6 6.3
Double Cell Light Filtering With Tracks 3.3 4.3 5.1 6.8
Double Cell Black Out 4.0 5.0 5.8 7.5
Double Cell Black Out With Tracks 4.7 5.7 6.5 8.2
Single Cell Light Filtering  1.6 2.6 3.4 5.1
Single Cell Black Out  2.5 3.5 4.3 6
*Single Cell Shades Aren't Available With Tracks

*Based on statistical reported values of equivalent products with the same construction.

Single Pane - A single thickness of glass in a window or door; found in half of America's homes.

Double Pane - Two panes of glass, separated by an air space (sometimes gas-filled) to improve insulation against heat transfer, found in most new houses.

Symphony, BlackOut, and Virtuoso and are EnergySmart insulating cellular fabrics. EnergySmart insulating cellular fabrics can aid in keeping homes more comfortable year round while helping to reduce energy costs.

A Quick Guide to Window Treatment Energy Saving Effectiveness

Two numerical values can help you easily compare the relative energy saving strengths of any window treatment are their R-Value and Shading Coefficient.

R-Value is primarily used as a measure of comfort in winter and indicates a fabric's ability to reduce the flow of heat through it. The higher the R-value, the better its resistance to heat loss or gain. A double honeycomb cellular shade (like our Symphony line) with its high R-value has superb insulating values which can result in substantial energy savings, year after year.

Shading Coefficient is important in hot weather and indicates a fabric's ability to reduce heat flow from the outside through a window shade to inside your home. A shading coefficient of 0.35 means 65% of the heat stays outside. On a hot day, heat coming in through your windows can raise room temperature by 15-20 degrees and make your air conditioning work two to three times harder. A lower shading coefficient translates into less heat gain, more reflected heat, and lower cooling costs for you. More on cooling window shades...

Two other comfort-factors you might want to consider when selecting your shades or blinds:

  • Light Transmission, UV - Although, not visible to the human eye, ultraviolet light from the sun can fade wood floors, carpets, and furniture after prolonged exposure. UV blockage ratings measure a fabric's ability to keep these harmful rays from passing though the shade.
  • Light Transmission, Visible - A measure of the amount of light passing through a shade that you can see. The lower the value, the more "room darkening" the shade will be, and less likely that light will pass through it.