A Challenge Within the Industry

      I have been in the architectural window and curtain wall industry for almost 40 years and for the last 5 of those years I have focused almost exclusively on designs that involve improved thermal performance. Why have I done this? Because 5 years ago I started to see articles and white papers written about sustainable buildings and how buildings account for more than 50% of energy usage in this country. The 2030 challenge was starting to take hold, an initiative by Edward Mazria and Architecture 2030 to make all new buildings and renovations carbon-neutral by 2030. Architects were looking at lighting controls, high-efficiency HVAC systems, better-insulated roofs, and walls. What I didn’t see were any major improvements in the products being offered in my industry, even though 50% of the energy used literally goes out the window due to inefficiency.

      So, I decided I wanted to make a difference. I am not a tree hugger or an environmentalist, but I want to try and leave this world in better shape than it is today. The effects of climate change are real and cannot be discarded. We see it in not just temperature increases but also in larger and more destructive wildfires, less rain, less snow, more hurricanes, and the list goes on. We have about 5 years left before the effects of climate change are no longer reversible, so I felt now is the time for our industry to make a major contribution to help everyone meet the 2030 challenge, and when I say major impact, I mean major. For years there have only been incremental improvements in the thermal performance of window and curtain wall systems. I wanted to make gains in thermal performance that would be industry-changing and make an impact on climate change.

      I needed to determine where the industry was currently, so I started to run simulations using Windows 7.2 simulation software and the NFRC 100 gateway size. I have run 100’s of thermal simulations of systems that use 1” insulated glass, fat triple, vacuum insulated glass, and thin triple, all with single Low E, double Low E, Argon filled, Krypton filled, warm edge spacers, and the list goes on and on. I have run simulations with every glass make you can think of using every type of frame available. What did I learn? Well, no matter what glass I used, the frame was always the weakest link. The industry still uses the same thermal barriers it did 40 years ago; poured and debridged urethane, polyamide struts, and gaskets. Sure, they have added different profiles and larger struts, but in the end, they have only made marginal gains in performance.

      I also learned that the industry was so focused on the center of glass (COG) performance that, for the most part, the edge of glass and frame were ignored. No matter what framing system and glass combination we analyzed, the results were always the same, the assembled U values were significantly higher than the COG. For instance, when analyzing a 1” insulated unit with a COG U factor of 0.29 placed in a strutted curtain wall, the assembled U factor increases to 0.41. This is a delta of 0.12 and represents a huge loss of energy. And this delta did not get any better as the glass performance improved. We analyzed a VIG hybrid (VIG assembled on the inside of an insulated unit) in a strutted system. The glass has a COG U of 0.059 (an R17) and the system assembled U factor was 0.17 (an R5.9). When the glass cost alone is $40/square foot and you lose more than 50% of the insulated value, is it worth it? For the record, the edge of glass performance of the VIG was the worst case we found. Two pieces of glass separated by a .3mm piece of metal, or some type of non-insulated material, does not provide any insulated value.

So, what did we do?

      We focused first on the framing system because this would make the largest impact and the finished product needed to have the same appearance as all current systems. We also realized we had to think outside the box and look at materials currently not in use in the industry. We developed a new way to insulate the interior frame from all exterior elements and the delta between the COG and assembly the old systems of 0.12 was reduced to 0.05. But we did not stop there. We have continued to improve the system performance and today we can achieve an assembled U factor of 0.142, a R7, on a unitized curtain wall at the same cost as a standard strutted system. This is the major impact we wanted to bring to the market, and it is available now.


With benefits like:

  • R7 versus R3 at the same cost
  • Reduction of carbon emissions of up to 60%
  • Savings of up to 50% on energy costs
  • Upfront reduction costs on HVAC systems
  • Improve occupant comfort
  • Elimination of condensation concerns
  • Savings in both cold and hot climates

Who would not want to put this on their building?

I can hear the excuses now and have for the last 4 years:

  • It’s too new (it’s been fully tested and around for 5 years)
  • Not sure about the material (the material has been around for years)
  • Don’t want to be the first (you won’t be)
  • Don’t need per the codes (the codes are behind and will not catch up in time to impact climate change)
  • It’s too expensive (even though I just said it’s the same cost)


      And the list goes on. All I have to say to all of that is put up or shut up. Either you want to strive to meet the 2030 challenge, The Climate Pledge co-founded by Amazon, the Green Building Initiative, or reverse climate change, or you don’t… but don’t be a hypocrite. If you want to stay with the old products and the lower performance that is your choice but be honest about the fact you do not want to change. Just remember that no matter the product, all improvements come with change.

To those that want to move forward into the 21st century and save money, give us a call. We can help you.

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