Volume 9, Issue 9 - October 2008
FTC Explores how
Never in a million years … Maybe that’s what some people thought 30 years ago about low-E glass—a glass that could actually absorb the sun’s heat and re-direct it to its source. And look where we are now. Low-E glass is a mainstream product found on just about all windows produced today.
Just as low-E glass may have seemed like a far-off concept so many years ago, there are early development technologies today that could also be used to create energy-efficient windows, but have yet to reach their full commercial potential. High costs, production and even installation challenges have hindered such products from reaching mass market acceptance.
In order to increase the market acceptance of these products, the Department of Energy (DOE) and its Office of Energy Efficiency and Renewable Energy’s (EERE) Building Technologies Program (BTP) solicited proposals as part of a research funding project (applications were due July 8). The DOE has made funds available that will be put toward the development/selection of innovative new technologies, accompanying production design and engineering and commercialization that will advance market adoption of highly insulating windows for residential buildings in cold climates. According to the DOE’s funding solicitation, a key requirement of this opportunity is the ability of the product to achieve energy-performance targets (R5 or better) at a market-acceptable cost premium (less than $4/square foot). By doing so, the hope is to increase adoption and national energy savings. The DOE estimates that approximately $2 million will be available for up to three awards and projects will be 50-50 cost shared between industry and the federal government. DOE also expects to notify applicants accepted to receive the awards by November 2008.
“The goal of the BTP is to create technologies and design approaches that enable the construction of net-zero energy buildings at low incremental cost by 2025,” LaFrance said during the presentation. “In order to get there, we need R5 windows.” LaFrance explained that the technologies most commonly used today for energy-efficient windows are low-E glass and insulating glass units (IGU). While the products do very well, the market is stuck in terms of reaching an R5 value. “That’s really going to take something like a triple-glazed unit to get there,” said LaFrance.
According to information from the DOE, most of today’s highly insulating products are expensive, sometimes heavy and not widely available; they also have less readily apparent consumer benefits and manufacturers have been reluctant to invest in expensive production lines without clear market pull.
“In order for them to become more available it requires engineering and manufacturing investments to bring the costs down,” said LaFrance.
Through this research-funding
project, the industry and consumers
may find these products
“We need cost-effective products to get to these zero-energy buildings,” said LaFrance. “To get there, there has to be an investment in technology.”
Triple-glazed units may be a main focus area of this particular research funding project, but there are other products and technologies being developed that could also be used in the construction of a window with an R5—or even greater—rating. While advanced technologies are not the focus of this project, they could be considered so long as they provide the near commercialization required by this funding project. Looking even further toward the future and considering increasingly high energy costs, technologies such as vacuum insulating glass (VIG) and dynamic glazing, are just starting to emerge and could very well make their way into the conventional usage.
Vacuum Insulating Glass
“With VIGs you eliminate everything between the lites of glass and that creates a vacuum, which generates the highest possible insulating value,” says Andy Russo, market development manager for Guardian. “The bare essentials are the glass and the vacuum; because there is a vacuum you typically need something to keep the glass from collapsing on itself, so a spacer and some way to hold the glass together at the edges.”
According to Russo the technology behind VIGs is not new; in fact the technology is the same as that used in products such as thermoses.
“The concept is the same—it keeps hot things hot and cold things cold,” says Russo. “It’s the same idea, you’re just applying it to a window.”
Hurdles to Cross
“The industry is pretty conservative and doesn’t accept change very readily,” says Russo. “Because the technology itself is generally more expensive than a traditional glass assembly, something like the [increasing] price of energy is what will draw interest.”
He continues, “I think interest has been building over the years, especially if you look at what’s going on in Europe and the amount of triple glazing that’s used there. Here, we’re starting to see more triple glazed units, especially in aftermarket applications.”
The technology will have to overcome other obstacles as well, including high costs. In fact, one source says producing a VIG would double the cost of a standard IGU. But according to Russo, exactly how the technology will affect the cost of a window is uncertain.
“The cost of the material might go up a little bit, but [as far as] the actual sales price of the window, that’s kind of up to the people who are first bringing it to market,” Russo says. “If you’re the first on the market you could charge whatever you want. It doesn’t necessarily mean that the market will buy it across the board. If the window manufacturer has an exclusive he might charge more; if the company has three or four competitors it might charge less.”
Cost is not the only challenge. There are also technical issues that have prevented the product from coming to market. These include the ability of the glass to maintain a vacuum over time and the structural and thermal performance of the window in total. Russo explains, “You can create the IG assembly to perform a certain way, but when you put it into the frame or structure in the wall it might act a different way.”
Overall aesthetics may also be a disadvantage for some, because a VIG has a different appearance than a typical IGU; VIGs are very thin.
“The look is going to be different and the spacer may or may not be visible. If it’s visible that might be a negative for some,” says Russo.
“The first thing is to make a product that uses components that are not prohibitive,” says Russo. He explains that if a product required a very exotic material, for example, the cost would likely be extremely high. “The idea behind the VIG is a good one because you start with materials that are readily available and generally proven and inexpensive. It’s basically glass, the material to bond the glass and a spacer. If you put those things into an assembly, the assembly cost itself will be relatively inexpensive. What you have to do is figure out a way to make it and make it relatively inexpensively.”
If energy costs continue to increase, products such as VIG windows can help consumers offset their energy bills—but first there has to be widespread acceptance.
“The premium [consumers pay for the windows] could be outweighed by the savings. I don’t know what the payback would be … but if you double or triple the performance of a window, depending on where you live, that generates a tremendous amount of savings on an annual basis,” says Russo. Because people are sometimes skeptical about new technologies, the challenge will be getting the word out to consumers in a way that they are willing to adapt. Russo says having the whole market behind the new technology would help make it easily adaptable.
“Of course, there are different material types, but it’s done in a manner that very much mirrors the way low-E is produced,” said Van Dine. “[Our technology] is applied to the second surface of the IGU and then when you supply low-voltage power to it you can take the glass from a hightransmission condition to a very low transmission—all the way down to 3-percent visible light transmittance—and move the solar heat gain coefficient (SHGC) down to .09,” says Van Dine. “You still maintain the view and have connection to the outdoors but the glass has stopped all of the direct solar heat gain and the glare without the use of shades or blinds. Then when the environment outside changes (when it’s cloudy, for example) you can untint the glass and harvest a great deal of natural daylight.”
According to Van Dine, his company first delivered products commercially in 2004 in a very limited way.
“We did that exclusively with Velux in a limited manner. In 2006 we brought online a larger manufacturing capability here in Faribault, and have been delivering products since then,” he says, adding that the company also has plans to expand those capabilities.
“The only reason we have not been more proactive in the residential market is because as a growing company with a new product there is only so much we can do,” says Van Dine. “We felt as though we wanted to get our delivery logistics into a different place before we approach that market more proactively. We do residential work from time to time; we’re just not proactively targeting that audience as of today.”
He adds, “The value of our product is its ability to help the design community gain points within the LEED accreditation system. The product falls into four categories and with the changes happening to the LEED program … we believe we may be able to garner more points for the design community in the future.”
Challenges and Considerations
“Because we are a low-volume format, at this time we have a fairly high price point and production limitations,” says Van Dine. “We need to get the product out into a larger format; our current operations limit us to a maximum size and the design community would like to see larger sizes. Those are the main obstacles to broaden our use.”
Though the company has not yet fully ventured into the residential market, the product does offer at least one feature that may be particularly attractive to some window manufacturers. Considering the DOE’s proposed revisions to its ENERGY STAR® program, some window manufacturers may like the fact that the technology allows consumers to control the SHGC of their windows. Van Dine says employees from his company have attended some meetings involving these changes and “it is very clear that the real answer to the conundrum is[that] we need a glazing that can respond to different conditions,” he says. “If you just pause and ask yourself ‘why do we put windows in a building … in a home …?’ there’s only one reason, and that’s because people occupy buildings. If people did not occupy buildings there are other materials that have an R-value of 30 and these materials don’t need maintenance like windows do. We use windows because people want the natural light and they want the connection to the outdoors,” Van Dine says. “Unfortunately, when the sun comes around we have to pull shades and blinds to block it and that negates the reason we used the glass in the first place. Electronically tintable glass allows consumers to use the window to stop the energy when they need to, but still maintain the view and connection to the outdoors. It’s a product that deals with the urgencies of reducing energy consumption and it responds to the desires of those who occupy the buildings.”
Into the Mainstream
“New technologies that increase the insulating values of the windows will allow [consumers] to have houses with more windows and more light without impacting their comfort level and energy bill,” says Russo. “The industry has to move forward with these products in order to make our lives better.”
Van Dine agrees.
“If you look at the energy consumption of a building the weakest link is the envelope (doors/windows),” he says. “Dynamic technologies can respond to the current situation of the sun, whether it’s sunny or cloudy and adjust the SHGC of the window.”
He continues, “The environment in which we live is constantly changing—day by day, seasonally, it changes for different orientations of a building and it’s different for different geographies. The glazing industry today is based upon glass that is static. We now need a glazing that can respond to the parameters and the changes that take place throughout the day and geographies. So I don’t think we really have a choice but to move in that direction if we really hope to make an impact on reducing the energy consumption of buildings.”