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Volume 7   Issue 1               January 2006

Special Spacer Report 
Warm-Edge Appeal is Anything but Lukewarm 
by Alan B. Goldberg 

While much has changed since Thomas Stetson received a patent in 1865 for “certain improvements in the manufacture of window-glass” (which became known as insulating glass), the role of the spacer has not. A far cry from Stetson’s wood bar, spacers are now are an integral part of sophisticated systems, whether rigid or non rigid, organic or inorganic.

“We started making spacers in the mid 1960s, initially with cold-rolled steel, based on the future growth of insulating glass,” says Denny Raske, director of international sales for Allmetal Inc.

He says aluminum became another material of choice because it was easier to fabricate than other materials. While aluminum continues to be used in residential and commercial applications, materials and technologies keep changing in the interest of energy efficiency.

According to Raske, in the mid-1980s high-performance glass was beginning to take hold. Many factors had to be considered as spacer materials—organic and inorganic—were being evaluated. Thermal performance, compatibility with sealants, expansion and contraction and longevity of an insulating glass unit were among them. 

Warm-Edge Technology

Mike Gainey, Warm-Light business manager for Azon USA, says several factors are responsible for the emphasis on the edge conditions of insulating glass units. One of them is building codes that prescribe an overall U factor. Most commercial glazing applications have already been improved thermally with thermal barrier in the frames and high-performance glass in the opening. 

“The only portion that has not changed in 30 years of making commercial IG units is the spacer. This has created a weak link in the systems. It is the only spot that you can find improvement for the U factor.”

Technoform, based in Cleveland, Ohio, recently introduced its high-performance warm-edge spacer system. President Mark Silverberg says markets are moving more quickly toward warm-edge spacer products because global energy codes are getting stricter with the increasing cost of energy.

“Two of the largest IG manufacturers in Europe, who exclusively use our product, are producing five times the amount of warm-edge spacers they projected to produce in 2005 with continued growth in 2006,” he says.

Another factor, says Gainey, is that the coated glass industry is at a plateau for performance. The emissivity of double silver low-E products is so low that the U factor cannot be improved any further. 

Referring to condensation and mold, Gainey says that anything that can be done to control these conditions is welcomed by architects and building owners. 

“The resulting improvements in condensation resistance values (CRF) with warm-edge spacers cannot be achieved with anything else.” 

For Allmetal, the material of choice became stainless steel, “which we had been using since 1978,” says Raske. The market was demanding higher performance and heat conductivity was substantially lower than aluminum. 

TruSeal Technologies, which had been serving insulating glass manufacturers since the late 1960s, introduced its all-in-one warm edge spacer in 1979.

According to Pat Kreider, advertising and PR specialist, it was the first flexible insulating glass spacer to be marketed as warm edge, offering the industry a dramatic alternative to the cold-edge aluminum spacer.

Edgetech IG started making warm-edge spacers in 1989.

“We compete on durability, argon retention, service, quality and marketing support ... items that low-end spacers cannot furnish,” says Larry Johnson, executive vice president.

INEX Spacer has been serving the Canadian window and door market with its thermoplastic product for more than 10 years.

“More than 10 million IG units have been produced with our material,” says Sylvain Dubé, president. 

Cardinal Glass Industries introduced its warm-edge technology, a stainless steel spacer, in 1992, 30 years after it began serving IG manufacturers, according to Jeff Haberer, technical service engineer.

Entering the market in the late 1970s, with energy-efficient products, Azon introduced its warm-light spacer in 1995, as did Saint-Gobain Bayform.

“In Quebec, where it is much colder (than many parts of the United States), energy efficiency is certainly a factor because of high cost. But there are other factors which have contributed to the popularity of warm-edge spacers,” says Roger Lewington, director of sales for Saint Gobain Bayform. He pointed out that there are visual and aesthetic issues as well. Because of weather conditions, condensation around windows is a common problem. This, in turn, becomes a selling feature of warm edge. The appeal of color spacers to match the color of a window frame is another significant benefit. 

According to John Raycourt, sales representative for Saint Gobain Bayform, warm-edge spacers are very manufacturing-friendly.

“They work well with bending equipment, they are easy to assemble, they lend themselves to dual-seal operations and they have good adhesion.”

Future Markets

Ric Jackson, director of marketing and business development for TruSeal says the driving force behind what type of spacer is best suited to customers’ needs are equipment platforms. He believes that virtually all spacers are performing well in the market, but the main concern of window fabricators is production effectiveness. At a recent glass show, he pointed out that automation (regarding spacers) was the theme.

“Every major warm-edge spacer was demonstrated on automated equipment,” he says. “Increasing labor efficiency is a key opportunity that fabricators see as a way to try and offset rising raw material prices increases brought on by rising oil prices. We see this trend continuing as price pressure continues to increase.”

Marcel Bally, director of marketing and sales for Bystronic believes there will be a continuation of developmental emphasis on improvement in thermal insulation, gas retention and durability, mostly in commercial applications.

“Although I see incremental improvements in the residential fenestration market, I believe there is vast room for improvement in the commercial area. The focus will be warm-edge products for structural glazing,” he says.

Challenges Ahead

One challenge that continues to generate much concern is globalization. This can mean different things to different people. Bally views it as harmonization of codes and certification requirements. He says IGMA and ASTM are looking at adopting elements of the ISO/European standard. But globalization has another meaning as well.

“Chinese imports threatening North American IG manufacturers who are not efficient or not flexible enough to prosper in a changed environment is certainly a concern,” he says.

But Johnson sees it differently.

“I think foreign imports will only take a very minor part of the market in the next five years. Quality and lead times will be the determining factors,” he says. “Getting window manufacturers to look at building quality at the beginning [is the challenge]. Replacing an IG unit in the field is considerably more expensive.” 

Haberer points out that another challenge is the increase in customization. 

“We must be able to offer custom products and not be eaten up by labor,” he says.

Bally comments on the effects of the standard 20-year warranty.

“Considering the litigious nature of our culture, U.S.-based material suppliers should recognize the latent risk of being implicated, should inordinate IG failures occur for any reason during the 20-year warranty period. European material suppliers unable or unwilling to back IG manufacturers with warranties of their own in support of the 20-year IG warranty, will have a problem,” says Bally. 

Silverberg sees the role of the spacer manufacturer expanding.

“Progressive, customer-focused, spacer manufacturers have more involvement than ever before in providing integrated production solutions to their customers,” he says.

He says that includes every aspect of spacer processing from bending tolerances, sealant application and adhesion, to system knowledge for precise, repeatable machine-controlled location of muntins. The result is higher productivity, quality, unit durability and continuous improvement of IG manufacturing systems for fabricators.

Raske projects a bright future for warm-edge technology, especially stainless steel.

“As the evolution of thermally-performing inorganic products continues, stainless steel will play an important part in our industry,” he says. 

He says that with its thermal qualities and longevity, stainless steel is considered one of the best warm-edge spacers in the industry. 

Silverberg pointed out that some of the newer spacer systems offer dramatic improvements in CRF. He says that only simulation and physical testing by an independent lab make it possible to get a true comparison of relative thermal performance of spacer systems. Composites, which offer the benefit of reduced thermal conductivity, must be thoroughly tested by independent labs to ensure that all relevant industry testing requirements are satisfied.

Warm Edge Worldwide

The use and acceptance of warm-edge technology outside of North America varies.

According to Mike Hovan, president of Edgetech IG, the UK market is the most recent to jump on the bandwagon, mostly due to its need for thermally efficient windows. He says the situation is compounded with the UK’s attempt to comply with the Kyoto Accords and the tie-in with U values and energy savings. He pointed out that in Asia, there is a small percent of the market that is looking for high performance. As examples, he cites China, Malaysia and Indonesia. With an awareness of energy benefits, the desire and demand for warm edge is growing rapidly, particularly in China, which is preparing for the Olympics in Beijing and the World Trade Fair in Peking.

“They want high performance for many reasons, mostly to show the world that they are to be taken seriously,” says Hovan.

He points out that the European market is much more conservative. 

“At this point, they are insisting on metal in a window so it will take longer for warm edge to be accepted although we are beginning to see warm edge being offered as an option,” he adds.

“Our initial exposure to the European market has proven that the thermal benefits and energy savings from warm edge have very wide appeal, in residential as well as commercial applications. We are very encouraged by the reaction to warm edge technology,” says Dubé.

Hovan says the potential for warm edge in Korea is interesting because it is one of the most receptive to the importance and notion of thermal efficiency. 

“They have been using insulating glass for residential and commercial applications for years in an effort to be more energy efficient. This contrasts with Japan where there is a wait-and-see attitude. It is difficult for them to go from low cost to warm edge. Everyone is investigating but no one is pushing it.” 

Warm Edge in North America

Ten years ago, warm-edge materials represented 25 percent of the North American residential IG market, according to Raske. Five years from now, it could be 100 percent he says.

“It is estimated that over 80 percent of all new IG units in residential applications have some type of warm-edge spacer (anything other than aluminum),” says Gainey. “Over the next few years, the idea of warm edge will become standard for the commercial business as well.”

In Quebec, warm edge is a high percent of the residential market according to Lewington.

“I don’t see much of a change in the next five years,” he says. “There will always be a market for aluminum because of the lower cost. We could see a 5-10 percent gain [in warm edge] five years from now.”

Dube estimates the overall market share for warm edge in Quebec to be 35 - 40 percent.

For North America, Hovan estimates the residential market at 80 percent and believes warm edge could reach 100 percent in five years.

“The marketplace will demand it and legislation will require it because of energy savings,” he says. 

Alan Goldberg is a contributing writer for DWM. He has 31 years of experience in the insulating glass industry. 

© Copyright 2006 Key Communications Inc. All rights reserved. No reproduction of any type without expressed written permission.