Are Windows Entering An Electronic Age?

The commercialization of smart glass technologies is beginning, with suppliers targeting high-end buyers
Christina Lewellen
April 15, 2005
FEATURE ARTICLE | Products, Materials & Components

Glass is developing a “coolness factor.” Like cutting-edge electronics, smart glass products that switch from clear to tinted states or heat up to chase cool drafts away are beginning to attract the attention of consumers willing to pay a premium for the best technology for their homes. These types of glass technologies, which have been confined thus far to research and development labs and a few niche applications, are starting to find their way to the mainstream market. And based on the initial response, there is evidence to suggest that more widespread commercialization is beginning. “We’ve had great feedback on this technology when we present it,” says Joe Patrick of Velux America Inc., a company that offers skylights with glass that electronically darkens to block sunlight. “People ‘get it’ immediately. It has a coolness factor.”


Electrochromic Glass

In the battle against the sun’s heat, glare and UV damage, today’s arsenal includes shades, miniblinds and other after-market window coverings. Electrochromics, a technology that uses a low-voltage electrical current to control the tint of a coating applied to glass, has the ability to block the sun without covering the window or door opening, says Mike Myser, vice president of sales and marketing for Sage Electrochromics Inc., Faribault, MN.

Sage Electrochromics forsees tintable glass enjoying popularity in offices and media rooms, where people want to reduce the effects of the sun's glare for viewing televisions and computer screens.
Myser reports that traditional low-E coatings can block about 65 percent of the sun’s rays. In the clear state, Sage’s product can block about 82 percent of the sun’s energy; in a darkened state, it can block about 98 percent. “That’s a huge driver for people to reduce fading of carpet, artwork and fabric,” he says. “Today’s traditional solar-control method is to put a shade on it. We’re going to give people back their view, which is really the purpose of putting in a window in the first place.”

Sage produces its electrochromic glass by buying regular glass from a manufacturer and coating it with five thin-film ceramic layers, similar to how low-E coating is applied to glass. The company then fabricates the coated glass into a dual-pane configuration using an insulating spacer. It sells the IG unit and a control panel to window and door OEMs.

Electrons and ions in the coating applied to the glass are controlled with a low-voltage electrical current that enables the glass to go from an untinted state of 62 percent light transmission at its center to the most highly tinted state of 4 percent light transmission, Myser reports. “There’s a wide, dynamic range of how much light and heat the homeowner is able to control without ever losing the view.”

Sage partnered with Velux America Inc., Greenwood, SC, to produce high-end skylights with electrochromic glass. The product went to the marketplace more than a year ago when it was introduced at the 2004 International Builders’ Show.

Velux’s VSE line is a remote-controlled skylight that opens and closes with the push of a button. The product even has sensors to automatically close when it starts to rain. “This is the most sophisticated skylight on the market,” explains Patrick, product manager of skylights and flashing for the company. “This glass was a natural fit for this product. With the same remote control used to open and close the skylight, you can also darken the glass.”

Velux officials knew of Sage’s technology for a long time, Patrick says, and have been watching as the company has evolved and passed government testing. After solidifying the relationship in 2004, the companies did some test marketing and released their limited product offering at the start of this year. “We’re pleased and confident they have the most durable technology on the market,” Patrick says of Sage.

Currently, the VSE skylight with Sage’s glass is available in only one standard size. Company officials expect several additional sizes will be available in the final quarter of this year.

Patrick says the skylight with switchable glass is popular among buyers for its light and heat control and for reducing glare, especially in media rooms or offices. Still, most people who buy the product do so for its “coolness factor,” he points out. “Most people want it because it performs these functions and it’s cool.”

Myser believes that—like most technology—Sage’s electrochromic product will continue to evolve given more time and market acceptance. “What we’re introducing today is not the Pentium 4 technology. What you’ll find as time goes on is you’ll get clearer transmission in the ‘off’ state, darker in the tinted state and maybe a palate of colors. Everything gets better and better as time goes on.”

A long development cycle of a decade or more is necessary to work out the manufacturability and durability of the new product so it gains traction in the marketplace, Myser says. The result, he predicts, will be a revolution in the window industry. “What’s really changed in the window industry in the last 30 years? That’s not to say they haven’t gotten better. But from a homeowner’s perspective, is this a whole different industry? We believe that switchable, dynamic windows is a major change for the window industry.”

From a cost standpoint, however, it may take 20 years or more to be affordable to average homeowners, he admits. “Mainstream product manufacturers are not an appropriate customer for us today. Like any new technology, it’s often expensive when first introduced.”

Patrick expects that the technology will contribute to a good year for both Velux and Sage. “I expect [Sage] to announce several more relationships with notable companies in our industry. When you really get a number of companies like Velux promoting it, I think it’ll get a lot of play in the marketplace and there will be more sales.”

Myser’s not sharing pricing structures for Sage’s dynamic glass. But he will say that with the combination of easing costs as the product matures and the Department of Energy’s desire to see all homes become “zero energy” buildings by around 2020, more consumers may see the value in this type of technology. “Energy has never been that important to Americans. But that is changing. I don’t think anybody thinks energy pricing will be going down in the next 10 to 20 years. Energy consumption is going to become more and more important to the homeowner.”


Suspended Particle Devices

Like electrochromic glass, suspended particle devices—or SPDs—offer a variable tint that goes from a shaded to a clear state. The difference, however, is that SPD technology allows for an almost instantaneous change. “It’s the fastest switching, tunable smart glazing available,” says Greg Sottile, director of market development for Research Frontiers Inc., Woodbury, NY. The company is a research and development and licensing group that says it holds nearly all rights to SPD technology.

SPD is a film technology, Sottile explains. The product consists of five layers, of which layers one and five are plastic, two and four are a conductive coating and the middle layer is SPD emulsion—random microscopic particles that absorb light. When the SPD film is unenergized, it behaves much like a shade. When an electrical voltage is applied, the particles align and light passes through. “The particles are very dynamic and easily adjusted.” Electrical leads are located between the “sandwich” of layers and connect the film to the power source. For this reason, SPD film can be an after-market item, but only if the existing glazing is replaced with the layered technology, he explains.

Sottile says SPD film takes about one second to switch from dark to clear, or to go from unenergized to energized. The reverse process takes one to three seconds. Those change times do not increase as the size of the opening increases, he notes. With electrochromic technology, a skylight might take eight minutes to change, but a large panel might take 45 minutes, he says.

The speed at which the product darkens or lightens, according to Sottile, is a significant market advantage. “In the past year, I’ve presented this technology to at least 50 architectural firms across the country. This is an important feature.”

The power needed to utilize the technology is very low, Sottile says. “Our internal data indicates that if you have 100 square feet of SPDs fully charged, or clear, for one month, you’d use about 40 cents worth of electricity. When they’re not powered, they go to the default state, which is dark.”

Research Frontiers has 34 licensees, of which about two-thirds are end-product manufacturers. They sell to various markets, including architectural, aircraft, automotive and marine. On the residential side, the SPD film is finding its niche in exterior windows, skylights, sunrooms and home theaters, Sottile reports.

Like Sage Electrochromics, Research Frontiers is not sharing its pricing. But also like Sage, Research Frontiers expects pricing will drop as the technology becomes more accepted. “The category on a per-square-foot basis is absolutely more expensive than traditional windows or other types of shading equipment,” Sottile says. “But if smart glazing and SPDs follow the very typical technology path, we’re looking at prices right now being at their highest point. If the market adopts them, there’s no doubt in my mind that prices will drop.”

So the real question, then, is will the market latch on to the technology?

That is exactly what Research Frontiers set out to answer in its 2000 survey of 50 window manufacturers across the country. “Five years ago, we were gearing up for the commercialization of SPD film. What we wanted to do is get a sense of how window companies felt about smart glazing, what they knew about it and what they wanted to see from it.”

The general result, according to Sottile: Most manufacturers are aware of smart glazing and switchable products in concept, but are unclear as to how they work and the full range of benefits they offer. “We thought, if these senior vice presidents of window companies don’t know about the technology, how can we expect architects and consumers to know about it?”

Research Frontiers and its licensed companies are marketing the technology by giving presentations and attending industry trade shows. “We’ve got a stable of companies talking to potential buyers all across the country and the world in a number of industries,” Sottile points out.

He says of window manufacturers and architects, “I can only describe their attitudes as bullish.” With enough promotion and customer awareness, he believes SPD films will become a commonplace option available to the end buyer. “I’m 100 percent convinced that this technology will be the glass of the 21st century. We’re all making some history here.”

Used as a towel warmer in luxury hotels, Hot Glass is now finding a home in the residential window market, especially in cold climates. 

Heated Glass

Electronic glass options are not limited to products that change appearance and light transmission. Another concept is heated glass. Using a conductive coating, it has been used to eliminate condensation on refrigerator doors for a number of years. Now, companies are looking at using similar technologies to eliminate drafts caused by convection cooling. The goal is to make the area near the window more comfortable by heating the interior pane of glass to room temperature or warmer, thus making homeowners less likely to hike up the thermostat. In Europe, heated glass is available as an option on conservatory products in place of more conventional heating systems.

The appropriately named Hot Glass by Engineered Glass Products, Chicago, features a metal oxide coating on a basic piece of glass. Film conductors provide uniform heating across the entire glass surface, says Jim Runnells, vice president of marketing and new products for the company. Electronic controllers allow the user to manage the flow of energy to maintain a certain temperature. The coating is applied to the inside pane of an IG unit only to increase comfort for those inside the structure. “When people are able to walk up and touch both sides of the IG display units, they can feel for themselves that the outside is cool and the inside is warm. Literally, the look on people’s faces is worth a thousand words. It has an immediate impact, and they can understand what it can do for them.”

Unlike wired heating technologies, Runnells notes, this product does not have any detectable wires running in the glass and does not offer inconsistent heating. “With this coating, you get uniform heating across the whole surface, not spots of heat.”

Pointing to long-time use in the food service industry and the fact that the product can be found in many convenient store displays, Runnells says his company is interested in looking at new opportunities. One product it has developed are towel warmers, popular in luxury hotels.

In the window and door arena, Runnells reports his company’s technology has found a market among homeowners in the Rocky Mountain region who have big picture windows to accommodate the views—and the cold-air drafts to prove it. Research and development officials also see potential among restaurant owners who suffer from dwindling floor space in the wintertime thanks to the uncomfortable cool air coming from large windows. “We’ve taken a different path than regular IG fabricators. Rather than adding more glass or finding different glass, we’ve heated the inside pane so that the glass can be at the comfortable temperature you want,” Runnells says.

The new launch into the window market has resulted in several high-end residential projects in the Colorado mountainous areas. The company also is working on two U.S. commercial applications, Runnells notes. “We’re looking to sell to the IG folks. The IG manufacturers are always looking for ways to build their business, and this is a new way to add dimension for their customer.”

Engineered Glass Products just recently moved into the residential window market, having introduced Hot Glass to attendees of this year’s International Builders’ Show in Orlando. The company is focused on signing up distributors of the technology and then will support joint marketing efforts, Runnells explains. It has teamed up with Busick Insulated Glass in Denver—also known as Colorado Warm Windows—and expects similar partnerships with other IG fabricators as demand for the technology grows, he says. “In the next three to five years, if an IG fabricator does not have access to this technology, they’ll certainly not be as on the cutting edge as everybody else. Something will be missing from their product portfolio.”

Runnells says one of the biggest challenges in introducing this technology to the marketplace is wiring the glass during installation. In fact, the company is putting together a certification program to educate installers specifically about Hot Glass. “We’ve been challenged with how we can make it easy for the electricians to put this in and for glaziers to install the glass. That’s why we’ve been so careful of how to go to the market.”

The company also wants to maintain a reasonable rate of growth as it enters a new market, he says. “Our challenge is to follow our plan so we don’t get too overwhelmed. That’s why we chose one IG fabricator to start with. We’re testing everything to death to understand it and want to make sure we fully characterize this technology. At the same time, we don’t want to go so slow that people are disappointed.”

While the natural birthplace for Hot Glass is in northern climates, Runnells also expects that in time there could be some demand in southern regions. “I grew up in Florida, and one of the biggest problems down there is condensation. We will focus on northern regions but fully expect in the longer term to be pushing this in southern markets as well.”

The company has already sanctioned one research project to investigate the energy use-versus-savings associated with the technology. The findings were that, at the very least, the technology is energy neutral, Runnells explains. “But the study didn’t take into consideration people turning down the thermostat because of increased comfort levels.”

Cost and pricing questions are met with similar responses by Runnells as by the makers of other new glass technologies. “Initially, it’ll be high end because of cost of development and initial installations. But with anything, the more experience you get, the more cost management you get. We should be able to move pretty easily into the mass market.”

Runnells adds that there are always new ideas and concepts in development that could fit well with heated glass technology. “Because the technology passes electricity through the glass, it can also be used as a security device, for example. When the glass breaks, you break the electrical current. The controller could be set to sense that and send a message to an alarm center.”


I now pronounce you…

Makers of new glass technology are confident that there’s room for everybody in today’s marketplace. While shading and sun protection may be more important in one climate, more comfortable interior temperatures may take precedence in another. An additional possibility is that these new technologies will eventually work together.

“I fully expect that these technologies may marry,” Runnells says, citing heated electrochromic glass as an example. “I don’t see where a lot of people are going to want to use both of these, but there may be areas where they cross over.”

Sottile agrees, noting that just like the various glass and frame options available in the window and door industry today, different technologies fill different needs. “The glass industry is a very big market. I think what you’re going to find is that the market’s going to discover there are various needs out there and there are a variety of products that can meet those needs.”

Although Sottile sees potential for blending different glass technologies, some are so new that he’s hesitant to guess what the future market will look like. “I do see some combining. I don’t see how the shares are going to shake out over time, but I do see a lot of room [for growth], especially because of the values of these things. These are really innovative technologies.”

Traditional suppliers of glass and IG products expect these products will eventually make their way into the market, but are cautious about predictions. Ric Jackson of Truseal Technologies, Beachwood, OH, says he believes most people in the window and door industry are keeping an eye on new glass technologies to see how they perform, what manufacturing requirements they have and how the price structure will evolve. Buyers of the technology in the short-term will be high-end users who want the technology for the sake of technology, he suspects. He cites an outdated price quote, more than three years old, of $100 per square foot for electrochromic glass. “That’s an incredible premium to pay. There are very unique elements to it, but with a conventional IG unit with a life expectancy of 20 years, there certainly isn’t a payback.”

“The key is, can the technology advance to a point where it becomes cost competitive?” Jackson concludes. “When low-E was created, the cost was considerably high. Now it’s down because of efficiency in the process and it offers cost benefits to the consumer. Whether new technologies can do the same thing through volume is hard to say.”

Contact Christina Lewellen, senior editor, at