Volume 9, Issue 8 - September 2008
Are residential aluminum windows a thing of the past? Or, with the recent emphasis in the building market on green products and sustainability, are they the wave of the future?
“Either [consumers] want wood or [they] want vinyl, and aluminum has pretty much gone to commercial applications like curtainwall,” said vinyl window manufacturer Viwinco’s president, David Barnes on a recent radio program (see related story on page 54).
However, according to the aluminum window manufacturers interviewed for this article, the residential aluminum window market is alive and well. And, with the introduction of the new green building programs, their use is increasing at a fast rate.
“Aluminum windows have been a standard for years and years in construction, and they’ve continued to evolve to meet the structural and energy requirements as time has gone on,” says Terry Newcomb of Thermal Windows, an aluminum window manufacturer based in Tulsa, Okla. “They’re the only solution for many constructions where high structural needs are required.” Why Aluminum?
Aside from their structural stability and the sustainability programs’ recognition of aluminum window products, manufacturers and distributors always have a marketing strategy. So, how do they convince customers to go with aluminum? What are the benefits?
Most manufacturers will quickly give you a lengthy list. Longevity is usually at the top.
“You’ve just got a very resilient product that stands the test of time,” says Mark McCoy, vice president of sales for Fleetwood USA of Corona, Calif.
William Jordan, president of Georgia Palm Beach Aluminum Window Corp. in Bainbridge, Ga., concurs.
“[Aluminum windows] will be stronger in 100 years from now than they are today, as aluminum gets harder and harder as it ages,” Jordan says.
Builders appreciate this as much as the end-user does, says Mark Gallant, vice president of marketing for the Dallas-based Atrium Companies Inc.
“Our builders appreciate the stability of the frame material,” he says. “It can withstand a little more moving around [and] a little more rough handling.”
The precision of aluminum also is a plus.
“With vinyl, you can work in terms of a one-hundredth of an inch, and aluminum is stiffer, [so] you can get within one-thousandth of an inch, and you can get better performance,” says Dennis Lane, president of Thermal Windows.
One of the factors in an aluminum window that often is considered a negative is actually what makes it last so long, McCoy says.
“Aluminum does conduct energy— nobody’s disputing that,” he says. “That’s one of the reasons it’s so resilient—it doesn’t trap energy. Wood and vinyl trap that energy, and they deteriorate over time.”
But the list of aluminum’s benefits doesn’t end with strength and longevity. Many manufacturer representatives also note that customers appreciate the appearance and customization of aluminum windows.
“You can go to the very dark colors [with aluminum], which is more difficult for vinyl because of the heat gain and distortions that [can occur] when very dark colors are applied,” Gallant says.
The coatings that can be applied to aluminum also provide an environmental benefit, Lane says.
“We use a powder coat, which contains no volatile organic compounds [VOCs] at all,” he says. “Our pre-treat process is non-chromate—chromate is a nasty chemical that we do not have on our premises and is required with wet paint.”
The powder coating also has aesthetic benefits. “The spray powder coat is very attractive, and it doesn’t have the ripples that a wet paint can,” Newcomb adds.
Aluminum window manufacturers also have made advances over the last 50 years that have increased their value to consumers. The main advance on this front was the development of the thermally broken aluminum window, which are made by separating the outside aluminum portion of the window from the inside portion with a polyurethane barrier, which decreases the amount of heat or cold transferred through the frames.
“With aluminum thermally improved windows, the inside [temperature] stays inside and the outside [temperature] stays outside,” Newcomb says.
What About Green?
“If you look at the U-value prescriptive test on a double-hung thermally broken aluminum window, it might be .46, on a vinyl window it might be .40, but that test doesn’t taken into account how much air leaks around the sash,” Lane says. “That’s where a thermally broken product will outlast a vinyl product.”
“ENERGY STAR doesn’t take into account long-term performance,” Newcombe adds.
Gallant adds that with the upcoming changes to the ENERGY STAR criteria, he expects it to become even tougher for aluminum window manufacturers to meet the DOE’s qualifications for this program.
“There’s a lot of changes going on there that will place more challenges on aluminum,” he says, but notes that ENERGY STAR is “a goal, not a mandate.”
While aluminum windows are long-lasting, if they are removed or replaced, they’re also recyclable— and often are made from recycled content as well.
“Once mined and produced, aluminum is used perpetually,” says Newcombe. “It goes right back into a scrap pile and right back into a furnace and it’s reproducible.”
Thermal’s windows are made up of 40 to 45 percent recycled content, and the company recycles all of its scrap. When it comes to green, lifecycle analysis also is an important factor. “Aluminum can be 100 percent recycled and it has a potentially much longer life cycle,” Gallant adds. “So when you look at the whole life cycle of aluminum, it has a good compelling story, because of the overall sustainability.”
The LEED for Homes Program is just one of the programs that recognizes aluminum’s sustainability, along with its ability to be recycled.
For aluminum window manufacturers that have struggled with the ENERGY STAR criteria, this is a welcomed benefit.
“We’re really kind of excited about [LEED] because in the past ENERGY STAR has dominated the standards,” Newcomb says.
McCoy also points out that it’s important to stress that aluminum windows are sustainable—not “green.”
“A wood window is very green, but it’s not sustainable—unless it is made from a tree from a forest that was grown 50 years ago,” he says.
Both Thermal Windows and Fleetwood have been approached by numerous architects and designers wishing to achieve the highest number of LEED points for windows in their projects by using aluminum windows. Twenty-two of Thermal’s aluminum windows and two terrace doors were used recently in the first LEED Platinum structure in Oklahoma, the Tulsa Green Lofts project (see sidebar on page 30).
“The architect came to us about a year ago and he was wanting this building to have the highest number of LEED points available, and he realized if he put vinyl windows or wood windows in it, he couldn’t get as many points,” Newcomb says.
Fleetwood recently was involved in the Living Homes project, and Project 710, both of which are located in Santa Monica, Calif., along with the Pasadena EcoHouse—all LEED projects.
While Atrium makes both a thermally broken aluminum window and a standard aluminum window, Gallant says the advantage for Atrium has been that both LEED and the NAHB programs allow trade-offs for various products.
“What [architects will] do is they’ll use the aluminum windows and will increase energy performance in the ceiling. They’re able to enhance other areas of the energy envelope, which will allow them to take a step down in the windows in using aluminum windows,” he says. “There’s more of a prescriptive path where you can make trade-offs.”
The American Architectural Manufacturers Association (AAMA) also recently began developing a green certification program, which aluminum window manufacturers expect to be accepting of them and their products.
“We’re really excited about the green certification program,” Lane says. “It would take into account a company’s policies and procedures and we would appreciate that, because it would put us on a level playing field with others.”