Tripe Insulated Glass - A Fad?

Not too long ago Henselstone attended a podium discussion with three representatives of the largest window and door manufacturers in the United States (which will remain unnamed) in front of a group of architects. The topic was energy efficiency and sustainability. The discussion turned into a three against one melee since our company was the only one promoting triple insulated glazing. "Nothing but a fad," commented one. "Unstable and bound to fail because the glass is so thick," piped in another. "Insulated glass is efficient enough, insulating the rest of the structure is far more important," was supposed to be the knock out blow against triple insulated glazing. Our representative remained quiet until they were done. Then he raised a cut-out sample of a 3 1/4" sash profile with a 1 1/2" triple insulated glass in it.

The glass had an R-rating of 11 (industry average is R3). The sash and frame had an R-rating of 6. Put together in a standard size window (3 feet by 5 feet) the units achieved an R-rating of 8. Counter intuitive to most, the larger the glass area the more efficient the window or door becomes. Consternation in the audience. Self satisfied smiles on stage. Then a question from the audience... It was all over for the big three after that.

Why do American manufacturers continue to spend more money on lobbying against energy regulations than on product development to create an R8, R10 or better window? Because American manufacturers are stuck with 1 3/4" thick sashes. They cannot accommodate 1 1/2 inch glass because their sashes can't support it. The only other option is to use a different gas in between the glass panes that would allow the glass to be as efficient but thinner. This gas (Krypton), however is very expensive. They could not compete against a European window with thicker sashes.

Here you have it! Sorry, we made our competitors angry. They are just the foot soldiers of an industry that has been milking products for cash that they developed 25 years ago. Meanwhile, the rest of the world spent a lot of money and resources on truly energy efficient products. Triple insulated glazing has not only become the standard in most European countries, it has proven to be a stable, reliable product with low failure rates, and easy manufacturability. Agreed, selling some weatherstripping to a homeowner 25 years ago would have increased the energy efficiency of his or her home by 100%. However, today buildings are generally much more efficient and tight. Better insulation materials, improved construction processes, and highly efficient HVAC systems have all taken a modern building to new heights when it comes to energy efficiency.

Why not deal with the last bastion of inefficiency? Over 60% of energy loss occurs through windows and doors. So, dear architects, builders, and homeowners. Don't be snowed by arguments supporting ancient technology. Your customers deserve better and will demand better. Energy efficient construction raises the attractiveness of a project, reduces the long term cost of ownership, and increases the resale value. Those are facts. Would that not be worth 10% more for your window and door package?

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