What Does It All Mean? Understanding the Terminology
You may have heard it before: R-Value. But what exactly is it and what does it mean?
Very simply, R-value is a measure of a given material's resistance to heat flow - how well it resists heat gain or loss. In short, the higher the R-value, the better the insulation it will provide for you.
R-Value and your Windows
Your windows themselves have an R-value. A typical window has an
R-value ranging from 0.9 to 3.0. (To put this in perspective, the insulation that is used to build a home today has an R-value in the low 40s).
These 3 pictures were taken of a window in Vermont using an FLIR IR camera. You can see that the glass temperature went from 28 degrees at 8 pm with no shade to 61.5 degrees with the shade down but no side tracks (9:13 pm) to 64 degrees with the shade down and with side tracks in place (9:16 pm). The shade in these photos uses our Double Cell Black Out fabric.
When down, the shade is sitting on the sill so it is interrupting the convection current thereby reducing that heat loss; and this kind of difference in temperature gradient certainly affects radiant and conductive heat loss. This amazing temperature difference will make the room significantly more comfortable - and save you a lot on your energy bill as you will not be driven to raise the thermostat.
Several factors influence the R-value of your windows:
R-Value and your Window Treatments
Adding cellular shades to your windows can as much as 62% of the heat transfer through a window pane (according to Alliant Energy).
Windows are the greatest source of wasted energy in your home. That's because heat always moves from warm to cold areas. In winter,
warm air from inside your home is trying to escape through your windows. In summer, the sun beating down conducts heat quite easily through your windows, heating up your home and straining air conditioners. In the end, you pay for this extra use of energy to heat and cool your home.
Energy efficient window treatments are one easy way to conserve energy and reduce your utility bills. To be effective, window treatments must trap air between the shade or blind and the window glass. Our
family of products has a wide range of insulation that act as a barrier to heat flow, helping you save money on energy costs. In particular, our EnergySmart shades provide superb insulating capabilities. Depending on your needs one or more of our products will likely provide you with your desired level of comfort, ambiance, and value.
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 Type
Double Cell Light Filtering
Double Cell Light Filtering with Tracks
Double Cell Black Out
Double Cell Black Out with Tracks
Single Cell Light Filtering
Single Cell Black Out
Note: Single Cell shades are not available with side tracks
*Based on statistical reported values of equivalent products with the same
Single Pane - a single thickness of glass in a window or door; found in half of merica'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...
other comfort-factors you might want to consider when selecting your shades or blinds: