What is R-Value?


  • Double Pane Window R- 1.8

  • Single Cell Light Filtering R- 1.6

  • Single Cell Black Out R- 2.5

  • Double Cell Light Filtering R- 2.8

  • Double Cell Light Filtering With Tracks R- 3.3

  • Double Cell Black Out R- 4.0

  • Double Cell Black Out With Tracks R- 4.7

R-value measures a material’s ability to resist energy transfer. The higher a material’s R-value, the better it insulates against heat or cold. A typical double pane window has an R-value of 1.8. The R-value depicted beneath each type of cellular fabric represents the insulating properties of the shade alone, not combined with the R-value of the window it may be covering

Cellular Shade R-value Comparison ChartShade OnlySingle Pane (+1)Double Pane (+1.8)TriplePane (+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*All R-Value data provided by Comfortex

Why You Should Value R-value

Quite simply, R-value measures how well a material reduces energy (heat) gain or loss. It’s a measure of thermal resistance, used most commonly in building and construction.

To put it in perspective, sprayed foam wall insulation has an R-value between R-14 and R-28, depending how thickly it’s applied. Your windows have an R-value, too. Double pane glass is around R-1.8 – roughly 9% as resistant to heat transfer as your walls.

Understanding R-value allows you to shop wisely so you can decide on the most efficient and cost-effective household resources. The higher the R-value, the more energy you save. Energy saved is money saved!

So, About Those Windows…

Now that you’re an R-value pro, you might be thinking about how much less insulating your windows are than your actual walls. You might be imagining how up to 50% of your energy bill is flying out the window, or how your living room turns into an oven in the summer. But don’t give up hope! There are energy-saving solutions to these drafty sheets of glass we’ve grown to know and love.

Cellular window shades are designed with R-value in mind: the honeycomb-shaped fabric uses air pockets to slow the movement of thermal energy. Air happens to be a fantastic insulator (a 3/4” pocket of air has an R-value of .87!). Between the air pockets of the shade’s honeycomb cells and the insulating shade material itself, energy loss doesn’t stand a chance.

Energy is always trying to expand. In the winter, the warm air inside your home naturally moves toward and out your windows, so that it can expand into cold, open air. In the summer, outdoor heat tries to make its way back inside your cooler home. Cellular window shades work as a barrier against both types of energy transfer, so you save year-round

Two of the most common types of insulating fabric are single cell and double cell, meaning there is either one row or two rows of insulating cells that make up the fabric portion of the shade.

You also have a choice between light filtering fabric and blackout fabric. Double cell light filtering cellular fabric allows natural light to pass through, but still maintains a nice, high R-value of 2.8. Double cell blackout fabric is lined with a thin, flexible foil that works to block out 99% of the sunlight and also amplifies the energy savings even more with an R-value of 4.0.

The final feature that makes our shades so energy efficient is the option to use energy-saving sidetracks alongside your cell shade. Sidetracks are plastic pieces that run the length of the window frame and intersect with the sides of the shade. They close the gap between the shade and the window frame, effectively “zipping up” your window for an even greater R-value. Sidetracks are available with all manual double cell shades.

Working the Sun with Insulating Shades

Another energy-efficiency catchphrase you should get to know is Solar Heat Gain Coefficient (SHGC). This represents the amount of solar heat that is transmitted through a window.

We all love that solar heat gain streaming in during the winter. Free heat! But once summer rolls around, it’s better to leave all the solar gain to outdoor enthusiasts and plant life. Your house should be an escape from the heat, not a sweat lodge!

What’s awesome is that it’s really easy to maximize your SHGC in the winter and minimize it in the summer when you have insulating window shades.

In the summertime, cellular shades reduce the amount of heat that penetrates through windows so your cooling unit doesn’t work as hard to maintain a comfortable temperature. Blackout shades block virtually all of the sun’s rays, and light filtering shades help soften the sun’s impact. If you don’t mind leaving the windows covered throughout the day, you’ll feel a huge difference, and your air conditioning will require a lot less energy to keep things cool. At the very least, use your shades strategically by lowering when the window receives the most direct sunlight.

In the wintertime, let in as much sunlight as you can by leaving the windows that receive direct sunlight uncovered. Let that solar heat seep right in! Once the sun isn’t shining in, lower the shades to keep the heat inside. Cellular window shades act as a barrier that not only contains drafts, but keeps heat from escaping outside. Your home will stay warmer longer.

The Department of Energy and the Environmental Protection Agency created the ENERGY STAR designation for products that meet high-performing energy efficiency criteria. If you’re interested in learning more about window criteria specific to your climate and location, you can start here!

Working with the sun

Show me the Money

So, let’s say you suited your home with some incredible, energy-saving window shades. Ten years go by, and with just the shades alone, you’ve saved $5,000 on your energy bills. What are you gonna do with that money? Here are some ideas:

  • Take a cross-country road trip!
  • Install a nice big solar panel and save forever!
  • Order 300 large veggie pizzas!
  • Buy window shades for a few other houses!
  • Invest in a wild new invention! Or invent something yourself!
  • Just rest easy knowing you’re $5K richer by saving natural resources every day!

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