If you’ve been in the building science, glazing, or architecture fields for any length of time, you’ve probably noticed the varying degrees of inadequacy characteristic of transparent envelope thermal performance. Frustrating, isn’t it ? It’s like we’re always stuck in THIRD-GEAR even though we’d swear we had a SIX-SPEED!¹

Although some curtain wall systems are certainly better than others in terms of thermal performance, few are what we’d call “good.” In an industry where “normal” curtain wall is second-gear (double-glazed Kawneer 1600, U_cw=2.2) and “high-performance” is third-gear (triple-glazed 1600UT System 2 with an aluminum pressure plate, U_cw=1.5), it’s not hard to see that “high-performance is broken,” to paraphrase Mosaic Centre² founder Dennis Cuku.

But what if there were a curtain wall system that could actually offer high performance fifth- and sixth-gear solutions (U_cw>=0.9) ? What if there was a system that could rightly eschew those pesky “high-performance” air quotes altogether ? What is there were something like, well, GlasCurtain ?

While GlasCurtain is often compared to fourth-gear systems (Kawneer 7550 or Alumicor 2600 with fibreglass pressure plates, U_cw=1.2), these systems aren’t as commonly used as you might imagine. Chances are, even if you’ve been in the industry for a decade or more, you’ve only seen such fourth-gear systems a handful of times. Instead we’re sold “high-performance” aluminum systems like 1600UT System 2 that use… aluminum pressure plates! But that’s still only third-gear!

So what’s the difference between even fifth-gear (GlasCurtain)³ and third-gear (Kawneer 1600UT System 2) ? Nothing less than 35% energy loss through your transparent envelope or 10%+ in total building energy use and commensurately larger HVAC systems to accommodate that delta. Not to mention greater ease complying with Building Codes and more LEED v4 points…

Suffice to say that high-performance curtain wall exists.

We just have to find the right gear.

1. You guys learned to drive manuals, right ?

2. The Mosaic Centre for Conscious Community and Commerce was just awarded LEED Platinum certification by CaGBC this week. A big congratulations to Manasc Isaac and their highly capable team on this incredible achievement!

3. GlasCurtain is certainly capable of sixth gear, as we’re demonstrating on the Nunavut Arctic College Learning Centre in Iqaluit and we only need slightly better glazing (eg. Solera) to get there, but even aiming for fifth gear (GlasCurtain with conventional triple-glazings and two low-e coatings) would be a huge step in the right direction for most projects!