Defining warm edge in the commercial market

Homes and buildings have a profound impact on our natural environment, economy, health and productivity. According to the U.S. Green Building Council, Washington, D.C, buildings in the United States account for 25 percent of electricity consumption, 36 percent of energy use and 30 percent of greenhouse gas emissions-the primary contributor to climate change. 

These realities have resulted in more stringent energy regulations from state and federal government agencies, as well as the governing bodies in the fenestration industry.

For example, the National Fenestration Rating Council, Greenbelt, Md., has approved a mandate that will require insulating glass certification as a prerequisite for Energy Star labeling. The group is finishing the language for certification program approval and expects to have this completed by its next meeting July 28-31 in Chicago. This government-backed program forces many manufacturers who are not certifying their IG-about 30 percent to 40 percent of companies-to change their designs to include low-E coatings and true warm edge spacer technology to achieve the performance and durability necessary for certification.

Some state energy regulators, such as those in California, are setting deadlines for homes and buildings to become net zero, meaning they will produce as much energy as they consume.

Such regulations have inspired or forced architects and window manufacturers to re-examine the ways they design window and wall systems. Windows are getting much of this attention because they have such a large impact on energy loss in a building envelope. Many are embracing warm edge spacer technology as part of their design for improving the energy performance of buildings, but are they getting what they expect?

Defining warm edge
In fenestration terms, warm edge only means the spacer is warmer than traditional cold edge aluminum spacers. As long as it improves thermal performance, even a relatively small amount, it is considered warm edge.
Using this definition, stainless steel spacer systems qualify as warm edge, even though they are made entirely of metal. While stainless steel and other metal-based spacer systems can offer some improvement over traditional aluminum spacers in terms of condensation resistance and U-values, it's undeniable that all warm edge spacers are not created equally. Stainless is still 80 times more conductive than other true warm options.

By choosing true warm edge technology for commercial applications, your design can reap additional benefits that are not possible with metal-based spacer systems.

And then there's the myth: It has to be metal to be strong.
That's a simple one to debunk. Today's true warm edge spacers have the strength needed to support large commercial IGs, even curtain walls, in some of the most challenging climates. The strength, performance and durability of these systems have been proven in the field for many years.

Getting ahead, not just keeping up
In European markets, which have been entrenched in the green movement for some time, IG producers are anticipating even stricter environmental regulations in the near future. Many commercial IG manufacturers are experiencing heightened pressure to create even better performing window systems to meet new energy regulations, especially in the United Kingdom, Norway and Germany.

These looming regulations are forcing producers to take a hard look at their designs. Many conservative design professionals are adding more materials to create triple-pane IG with stainless steel spacers. This often helps to make the system more energy efficient. It might not be the wisest and most economical way to meet the new regulations.

Another more logical school of thought is to consider quality over quantity. Producers need to re-examine the components they put into their systems and consider responding to the regulations with dual-pane systems that incorporate high-performance glass coatings, gas filling and true warm edge technology. Many European companies meet the highest demands for performance and durability with this approach. It is obvious that simply adding more conductive material to increase energy savings is not the most effective or efficient solution.

The United States is catching up with Europe in terms of tightening energy regulations. The green movement is alive, well and lucrative to many in the fenestration industry. Many companies have jumped on the green wagon feet first and, by making a few simple claims and a few nice ads, they consider themselves to be environmental stewards. But can their claims be substantiated?

Regardless of the industry, no one wants to be accused of green washing, yet they want to be part of a greater good. Building products need to be energy efficient and sustainable to thrive in our industry. We need to be sure our products and processes will still work when environmental regulations become increasingly stringent.

Research has shown that the selection of the right warm edge and commercial facade materials can make a significant difference in reducing overall energy consumption of buildings.

Therefore, claims of warm edge are not enough. 
Making the right warm edge choice includes calculating the life cycle cost for their systems. Automation options for flexible, true warm spacer systems can dramatically improve efficiencies while offering the best available long-term sustainable performance.

Those who are truly interested in making a difference and staying ahead of the curve should put the right fenestration products and processes in place. This will position you for the more stringent energy requirements of tomorrow. The road to net zero energy buildings is short. Be proactive now.


The author is product manager for Edgetech I.G., Cambridge, Ohio,, 740/439/6412.