The Science Behind the Hunter Douglas Products
At Hunter Douglas, we’re an industry leader in making a big energy savings difference at the window. In 1985, we invented the highly energy-efficient Duette® honeycomb shades in response to the energy crisis of the late 1970s. More recently, we’ve introduced Duette Architella® honeycomb shades, which offer superior energy efficiency thanks to their patented honeycomb-within-a-honeycomb construction, and Vignette® Tiered Architella Shades, featuring rear fabric air pockets that trap air and create an extra layer of insulation.
Without energy-efficient window treatments, as much as 50% of a home’s heating and cooling energy can be lost through its windows. All Hunter Douglas window fashions provide window insulation, offering your home increased protection against heat loss during the winter, as well as minimizing the sun’s heat or “solar heat” during the summer. More specifically, here’s how Hunter Douglas products help conserve energy at the window in these three significant ways:
Our window fashions reduce heat flow (both heat loss and heat gain) through the windows. Without energy-efficient window treatments, as much as 50% of a home’s heating and cooling energy can be lost through its windows. All Hunter Douglas window fashions provide window insulation, offering your home increased protection against heat loss during the winter, as well as minimizing the sun’s heat or “solar heat” during the summer.
It’s a scientific fact that heat is attracted to cold. In winter months, indoor heating moves toward and escapes through windows to the outdoors, while in summertime, the outside heat flows into your home through these same windows. Many Hunter Douglas window fashions help insulate homes; helping reduce energy consumption, save on heating and cooling costs, and creating a more comfortable room setting. The illustration right showing a window split – one side without a window shading and with an Architella honeycomb shade. The uncovered section is displaying very poor insulation and heat escaping thru the glass. The covered section (a green cooler color) is demonstrating the insulation provided by the window shading.
Solar Heat Control
Our window fashions help to control solar heat (heat generated from the sun) by allowing it into your home in the winter and minimizing the amount that comes in during the summer. Without energy-efficient window treatments, as much as 50% of a home’s heating and cooling energy can be lost through its windows. All Hunter Douglas window fashions provide window insulation, offering your home increased protection against heat loss during the winter, as well as minimizing the sun’s heat or “solar heat” during the summer.
The warmth provided by the sun, its solar energy, may be desirable during the winter to help heat your home, yet it can make a room overly hot and uncomfortable while driving up air conditioning costs in the summer. Many Hunter Douglas products are designed to reduce the amount of solar heat that passes through the window, which is known as the Solar Heat Gain Coefficient (SHGC). The lower the SHGC, the more protected your home is from the sun’s heat. To enjoy the sun’s warmth when desired, simply raise or open the window fashion and invite it in.
Our window fashions enhance daylighting (the use of natural light) by diffusing and dispersing sunlight deep into a room, reducing your need for electrical lighting. Without energy-efficient window treatments, as much as 50% of a home’s heating and cooling energy can be lost through its windows. All Hunter Douglas window fashions provide window insulation, offering your home increased protection against heat loss during the winter, as well as minimizing the sun’s heat or “solar heat” during the summer.
Daylighting is the practice of lighting rooms with natural light rather than generating illumination from electricity. With Hunter Douglas window fashions, you can control how much natural light comes into your room. Our sheers and other select styles actually diffuse light as it enters and help to draw it deeper into the room. You can also direct incoming light where it’s needed most by tilting the louvers, slats, vanes, blinds and panels. By drawing natural light into a room many of our window treatments reduce your energy needs for other types of lighting.
What does this mean for me?
- Window treatments can reduce energy use in your home, and are less expensive than purchasing new, energy-efficient windows.
- In addition to saving energy, window treatments can be aesthetic additions to your home.
You can choose window treatments or coverings not only for decoration but also for saving energy. Some carefully selected window treatments can reduce heat loss in the winter and heat gain in the summer. Window treatments, however, aren’t effective at reducing air leakage or infiltration. You need to caulk and weatherstrip around windows to reduce air leakage.
Window awnings can reduce solar heat gain in the summer by up to 65% on south-facing windows and 77% on west-facing windows. You can use an awning to shade one window or have an awning custom-made to shade the entire side of your house.
In the past, most awnings were made of metal or canvas, which need to be re-covered every five to seven years. Today, awnings are made from synthetic fabrics such as acrylic and polyvinyl laminates that are water-repellent and treated to resist mildew and fading. Whatever the fabric, you should choose one that is opaque and tightly woven. A light-colored awning will reflect more sunlight.
Awnings require ventilation to keep hot air from becoming trapped around the window. Grommets (eyelets) or other openings along the tops and sides of an awning can provide ventilation. The awning may also open to the sides or top to vent hot air.
You can roll up adjustable or retractable awnings in the winter to let the sun warm the house. New hardware, such as lateral arms, makes the rolling up process quite easy.
Window blinds—vertical or horizontal slat-type—are more effective at reducing summer heat gain than winter heat loss.
Because of the numerous openings between the slats, it’s difficult to control heat loss through interior window blinds, but the slats offer flexibility in the summer. Unlike shades, you can adjust the slats to control light and ventilation. For example, when completely closed and lowered on a sunny window, highly reflective blinds can reduce heat gain by around 45%. They can also be adjusted to block and reflect direct sunlight onto a light-colored ceiling. A light-colored ceiling will diffuse the light without much heat or glare.
Exterior roller blinds are usually made of wood, steel, aluminum, or vinyl. They’re mounted above the window, and side channels guide them as they’re lowered and raised. When you lower these blinds completely, their slats meet and provide shade. If partially raised, the blinds allow some air and daylight to enter through windows.
A drapery’s ability to reduce heat loss and gain depends on several factors, including fabric type (closed or open weave) and color. With such a wide variety of draperies available, it’s difficult to generalize about their energy performance.
During summer days, you should close draperies on windows receiving direct sunlight to prevent heat gain. Studies demonstrate that medium-colored draperies with white-plastic backings can reduce heat gains by 33%. Draperies also stay cooler in the summer than some other window treatments because their pleats and folds lose heat through convection.
When drawn during cold weather, most conventional draperies can reduce heat loss from a warm room up to 10%. Therefore, in winter, you should close all draperies at night, as well as draperies that don’t receive sunlight during the day.
To reduce heat exchange or convection, draperies should be hung as close to windows as possible. Also let them fall onto a windowsill or floor. For maximum effectiveness, you should install a cornice at the top of a drapery or place the drapery against the ceiling. Then seal the drapery at both sides and overlap it in the center. You can use Velcro or magnetic tape to attach drapes to the wall at the sides and bottom. If you do these things, you may reduce heat loss up to 25%.
Two draperies hung together will create a tighter air space than just one drapery. One advantage is that the room-side drapery will maintain around the same temperature as the interior space, adding to a room’s comfort.
When properly installed, window shades can be one of the simplest and most effective window treatments for saving energy.
Shades should be mounted as close to the glass as possible with the sides of the shade held close to the wall to establish a sealed air space. You should lower shades on sunlit windows in the summer. Shades on the south side of a house should be raised in the winter during the day, then lowered during the night.
For greater efficiency, use dual shades—highly reflective (white) on one side and heat absorbing (dark) on the other side—that can be reversed with the seasons. The reflective surface should always face the warmest side—outward during the cooling season and inward during the heating season, and they need to be drawn all day to be effective.
Several manufacturers have designed two- or three-cell pleated or cellular shades with dead air spaces, which increase their insulating value. These shades when measured & installed correctly can present the highest R-Values & Summer Cooling for your window. Hunter Douglas Duette Architella holds the highest industry energy rating as an inside mount treatment.
Window shutters—both interior and exterior—can help reduce heat gain and loss in your home.
Interior plantation shutters need a clear space to the side of the window when they’re opened. They also require hardware that is fastened to the window jams or trim.
Solid shutters will decrease both heat loss and summer heat gain. These insulating shutters consist of wood panels, a vapor barrier, and sometimes a decorative covering. If you fit them tightly against a window frame, they’ll provide an insulating air space between the shutter and the window.
You can combine shutters with other window treatments such as draperies for greater insulating ability.