Fight the Heat Wave with Energy Efficient Window Treatments
As Discussed on the Pete and Brenda Radio Show, July 14th and 15th, 2010, 12:40 and 9:40pm, PST
The Benefits of Window Coverings
Most people may not realize how much window treatments can impact energy efficiency…. Not only do window coverings help protect against UV damage to furnishings, block the light for sleeping, computer/TV screens and provide privacy, but they can also add insulation at the window to reduce heating costs, moderate the sun’s heat in summer to reduce cooling costs, and improve the quality of natural daylight to reduce the costs of electrical lighting.
The earth receives a large amount of solar energy… In summer, we don’t want that powerful energy entering our interiors and raising the heat even more— which is why if you live anywhere where summers are hot, you need window treatments that effectively reduce solar heat gain.
In this blog I discuss the energy efficiency and decorating qualities of:
– Shades and blinds
– Custom fabric window treatments
– Outdoor options
Shadings and Blinds:
Some people might be shocked when they purchase blinds and shades for a new house for the first time. It is an important investment that is always good to plan and budget for. The biggest reason people invest in window treatments is for privacy purposes, however another HUGE important reason is for energy efficiency. Fortunately today shades and blind products are much more than fashionable. According to Hunter Douglas, “They are tools to save energy resources, valves to control the flow of energy, and important contributors to reducing energy use, utility costs and greenhouse gas emissions. In fact, window coverings are one of the easiest ways to go green.
When choosing products with louvers, slats or vanes, opt for white or light colors. In summer, it’s important to reflect as much solar energy as possible right back out the window before it becomes heat.”
Click on images for larger views
Not only do the proper window treatments retain heat in the winter, they also help keep rooms cool in the summer. And for those who might be too busy or lazy to open and close their window treatments every day, they can be remote controlled for your entire home!
Highest Energy Efficient Ratings
Honeycomb shades have been out for a while, and they have always rated high in energy efficiency, however there have been new product innovations taking place that bring them to the top of the energy efficiency ratings. The Hunter Douglas brand called Architella takes energy conservation to a whole new level, and they have gone to great lengths to provide us with the energy efficiency measurement factors. (Discussed further below.)
Hunter Douglas’s Duette Architella® honeycomb shades, incorporate a patented honeycomb-within-a-honeycomb design that forms three air pockets to dramatically reduce heat flow at the window. If installed in every window of every American home, these shades have the potential to cut our annual energy consumption by 2½%. That may not sound like much, but it’s the equivalent of a 33% increase in fuel mileage for all passenger cars on U.S.
Below: In the infrared photo (center), the window covered with a Hunter Douglas Duette Architella shade (right) is shown to allow much less energy loss than the bare, bright red window, (left).
Solar Heat Bad in Summer, But Good in Winter
In winter, to reduce heating energy consumption, take advantage of as much free heat energy from the sun as you can. This means raising or opening the window covering whenever direct sunlight is shining on the window — in the morning for east windows, in the afternoon for west windows and most of the day for south windows.
Not only are the Hunter Douglas Luminette sheers exquisitely beautiful, when vanes are closed they offer excellent protection against solar heat gain and UV rays. With the vanes open, the sheer fabric softens and diffuses incoming light, bringing it deeper into a room. Combine them with custom window treatments, and not only will your windows save you in energy bills, but they will become beautiful focal points in your rooms!
Energy efficiency and savings on windows can be beautiful…
I love providing Hunter Douglas products because their information is an excellent resource. Here is how their shades and blinds stack up on fighting solar heat gain…
Solar Heat Gain Coefficient Solar heat gain is measured by a coefficient from 0 to 1 that tells us what fraction of solar energy hitting the window actually enters the home. Lower numbers are better. Standard double-pane windows have a solar heat gain coefficient (SHGC) of 0.76 — meaning 76% gets into the home. Add Luminette® Privacy Sheers and the number drops to as low as 0.20; only 20% of the solar energy enters the home to become heat.
Above: The lower the coefficient rating, the better the energy efficiency. Duettes are honey comb shades. As you can see above, shutters are also an excellent window covering to block out summer heat. Additionally with shades, the more opaque the fabric, the more energy efficiency you will receive. Here are photos of the other Hunter Douglas products that are great for blocking out the heat:
Above: The Hunter Douglas Pirouette shades are a newer and innovative shade style. They are very fashionable because they look like Roman shades when they are closed. However, what is really amazing about this product is that you can open the veins with sheer fabic inbetween them to let in or filter light while maintaining privacy, or you can pull them up all the way!
Woven shades are another newer trend for shades that provide a rich and highly decorative look. You can increase their energy efficiency levels by adding the privacy lining option as shown below…
Mixing textures is really hot right now, and it’s very fun to mix woven woods with other textures such as silk or faux silk draperies!
The Value of R-Values
R-values measure resistance to heat flow. The walls of a contemporary home typically have an R-value of 19, while standard double-pane windows only have an R-value of about 2. Window fashions like Duette® Architella® honeycomb shades can add up to four points to a window’s R-value, tripling the energy efficiency of a standard double-pane window and cutting heat loss through it by up to two-thirds. Imagine the impact of this much increased insulation on your utility bills!
Above: In measuring the resistance to Heat Flow, the higher the rating, the better.
If you live in a cold climate with significant heating required for more than half the year, you should select a window covering that adds at least one point of R-value to your window (the more the better). When a product is chosen for its insulating qualities, be sure to specify that it be inside mounted and fully recessed within the window casement. If mounted outside the window opening, cold air between the shade and the glass can too easily flow around the sides and bottom — greatly reducing the effective R-value of the window covering.
Depending on what your energy efficiency needs are, you can use the two charts above to determine which window covering choice is best for you. I have clients who haven’t had to worry about both blocking heat from coming in and keeping the cold out. Your specific needs are dependant on the climate where you are located.
**Limited time offer for Hunter Douglas federal tax rebate!** Purchase select Hunter Douglas Duette Architella honeycomb shades from Decorating Den Interiors now through December 31st and you may qualify for a federal tax credit of up to $1,500. Act before December 15th and you’ll also get a $25 mail-in rebate per shade. Insulating Duette Architella shades can even help lower your heating and cooling bills! Ask for rebate and tax credit details.
On next week’s radio show and blog, we’ll discuss additional types of window coverings that can provide energy savings.