The latest cover of Door & Window Market ([DWM]) magazine didn’t mince words regarding ENERGY STAR 7.0: “It’s go time.”

The new criteria for the prestigious EPA label will hit in just about a year, and the significant changes for U-factors and solar heat gain coefficients (SHGCs) will be driving manufacturers to make major alterations to their ENERGY STAR systems. As [DWM] notes: “The ability of double-pane glass to raise the sum performance of finished products has narrowed to a degree that in some cases necessitates moving to triple-pane, vacuum insulating glass (VIG) or thin-triple IG.”

A note here: High-performance, energy-efficient vinyl framing can likely hit the criteria with a well-made double. However, changing your framing system is a lot more complicated than changing your insulating glass (IG), which has left most manufacturers exploring the latter road.

So, if you’re not looking to change your vinyl, what are the options? Exploring that question brings us to today’s tip:

Consider the implications for your manufacturing process.

While traditional triples have long been a standby in Canada due to its considerably colder climate, American manufacturers have been satisfied to continue to eke as much performance out of a traditional double as possible, with good reason: Making triples adds a significant amount of more work to your production process. It also consumes significantly more raw materials in terms of the extra glass and spacer you’ll need to complete the units. Finally, triples are larger and heavier—and that can be a challenge if you’re trying to fit them into your existing vinyl system.

Vacuum Insulating Glass (VIG), meanwhile, is a new technology. And as we noted back in March, it’s expensive. VIG’s current price may not have your customers biting on what you’d need to charge to profit on such a design. It’s likely VIG will become more cost-effective over the long term but not in time for ENERGY STAR 7.0. Its newness also means the learning curve for manufacturing it effectively may be steep for your production crews, nor does the technology have an established track record for long-term performance. Again, that may change, but it’s something to think about.

Thin triples, meanwhile, have a few things going for them that these other options don’t. First, the manufacturing process for a thin triple broadly compares to that of making a traditional double and won’t require you to reconfigure your existing production process. Considering that your ENERGY STAR product line probably doesn’t represent the majority of the units you’re making and shipping on a given day, fabricating thin triples as needed on a manual hand table aside from your main line should be sufficient to keep up with your demand for such units.

You will need a spacer technology that can effectively accommodate the thin center lite that makes a thin triple unique. Warm-edge options with secure channels for the center lite — which are applied similarly to those in a traditional double — are available and shouldn’t create much of a learning curve for your technicians.

With a few other more minor modifications, thin triples represent the path of least resistance to hitting ENERGY STAR 7.0 criteria, at least when it comes to your manufacturing process. And that’s something to consider as we get closer and closer to the standard coming into official effect.

John Ryba is Technical Services Manager for Quanex. Doug Hauck is Senior Technical Services Representative for Quanex.


  1. Informative and timely article. Thank you.

  2. Whay V.I.G technology is expensive.. ??.. when comparing with layer of glass 4mm; spacer and adhesive as materials. Plus operation cost.. we found vacuum insulated glass in cost effective better than triple. At same isolation ratio.

    We in Egypt use refrigeration compressor to vacuum.

    Sorry Energy Star 7.0

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