Regulars and Shorts

Eco House: Awnings & Window Film

By James Dulley

Save energy and keep sun damage and heat under control with adjustable awnings and efficient window films, both available in DIY kits.
by James Dulley
The sun's heat and glare are pretty intense through our windows and my furniture is fading. I have seen some attractive adjustable awnings. Are decorative window awnings really very effective?

-Kay M.

New awning designs are effective for shading windows, blocking 60% of heat. Awnings with decorator fabrics are becoming quite popular for use on homes, both for shading windows and for protection over doors.

Installing awning kits will lower your air-conditioning costs and improve your comfort. It can also increase the life of your furniture, carpeting, books, artwork and drapes. The same ultraviolet (UV) rays that cause fading actually degrade and weaken fibers.

The new lightweight awnings, with strong aluminum frames (hidden under the fabric), require little maintenance. An occasional brushing of the awning fabric and rinsing with water and Ivory Flakes keep it looking like new. Many awnings have a five-year warranty on the hardware and the fabric.

The basic design choices are adjustable and fixed. Adjustable awnings give you precise control over the level of shading year-round. In the winter, you may want to let more sun in for free heat. Keep in mind, though: Furniture fading occurs in the winter, too.

From indoors, using a pull tape or a switch, you adjust the awning position to cover as much glass as you wish. A half-inch hole is  required. For the ultimate convenience, install a remote-controlled electric motor. The motor is hidden in the awning fabric tube.

As you open an adjustable awning, two spring-loaded arms keep the fabric taut for an attractive appearance. For privacy, security or during storms, some models (like the Solaro and Perma System) adjust nearly all the way down (160 degrees) so the awning lays almost flat against the window.

Fixed designs, because of their simplicity, are less expensive. They are also the easiest to install. When choosing one, be sure it's sized properly. The correct size depends on the window size, your area's latitude and the window orientation.

One new design, Poncashade, is delivered in a flat box with a preassembled hinged frame. The acrylic fabric is already attached to the frame. You just drill four holes to attach the awning to your house. It took me about 10 minutes to install one over my own back door.

If you are primarily interested in the appearance of awnings, English-style canopy designs are a good choice. These are available in three-, four- or five-rib, ellipse or circular designs. Retractable canopy designs are available, but they do not adjust. They are either fully up or extended.

The sun's heat and glare are uncomfortable coming through the windows and it is also fading my furniture and carpeting. Will applying clear inexpensive insulating window film minimize these problems?

-Jack N.

dullywindowfilm.jpgNew insulating window films can reduce heat and glare by more than 50% and block nearly all the sun's ultraviolet fading rays through your windows. True insulating window films also reduce heat loss during winter and make sitting by a window more comfortable year-round.

Insulating window films are not totally "clear," but the tint in some is so slight that when applied to the window glass, it is barely noticeable. All window film makes glass more shatter-resistant. Some heavier films can also enhance security against window break-ins.

Window film is available in rolls or single window boxes for do-it-yourself (DIY) application or from professional installers. Installing it yourself can save up to 75% compared to  professionally installed film.

Residential window films are considered permanent because, with proper cleaning, they can last 10 years or more. If you decide to remove the film at a later date, the manufacturers offer removal solutions that quickly dissolve the adhesive. The window glass surface is not harmed.

The primary difference between DIY and professional films from companies that offer both is the type of adhesive used. On all but the largest windows which require more installation skills, DIY application looks as good. Professional installation does have the advantage of  a long warranty.

True insulating window films derive their energy-saving/comfort properties from a low-emissivity (low-e) coating in the film. This is the same low-e technology used on new super-efficient replacement window glass.

This low-e coating is a microscopically thin layer of metal on the film's inner layer. Visible light passes through this layer. Heat energy from the sun and reflected from walkways, patios, and other surfaces is a different wavelength than visible light; the low-e film blocks it. During winter, this film also keeps heat indoors.

Energy-saving qualities vary widely for different window films, so don't just buy the cheapest film on sale. Compare the film properties first. The emissivity is a key property to determine year-round insulating/comfort value. Shading coefficient indicates how much heat/glare are blocked.dullywindowfilmgraph.jpg

If you can wash a window, you can easily install insulating window film yourself. You purchase the film, in pieces from a roll or in boxes, and a simple installation kit. Most films have a water-activated adhesive on one side. 

Download (from Update Bulletin No. 736-buyer's guide of adjustable and fixed window and door awning kits (canopies, small and large adjustable awnings, adjustable vertical awnings), widths, projections, fabrics, features, suggestions on measuring for an awning, recommended cleaning of acrylic awnings, benefits of a fabric awning, explanation of how awnings save energy, prices and illustrations. $3.

Download (from Update Bulletin No. 617-buyer's guide of do-it-yourself and professional window film manufacturers (34 films) listing colors, properties (total solar transmittance, total solar reflectance, total solar absorption, visible light transmittance, ultraviolet rejected, U-factor, shading coefficient, emissivity, total solar energy rejected), prices, definitions/technical terms of the properties and installation instructions. $3.

Send questions to James Dulley c/o

This article was originally published on May 31, 2007.