Newer insulation products and technologies mean new options for enhancing energy efficiency while still maintaining design aesthetics and solving practical execution issues—and that includes glass. That was the overarching takeaway from yesterday’s webinar, “Improving Building Enclosure Thermal, Performance and Design Freedom with High-Performance Insulation,” from the Construction Specifications Institute.
A truism ever since the time that “energy efficiency” became part of the industry lexicon, of course, has been that energy efficiency and design are usually divergent goals. That’s becoming less the case, it seems.
“New technology such as vacuum insulation panels (VIP) offers a great deal of potential for design freedom,” said Stanley Yee, building design specialist at Dow Corning, who presented the webinar.
Of the products discussed, the topic of VIP particularly resonates from a glass-industry perspective.
While VIP have been around now “for some time,” as Yee said, they deserve close consideration for a number of applications, thanks to their flexibility and other advantages. VIP-enabled spandrels, for example, can enhance performance for curtainwall, with VIP-integrated façade modules (e.g., for commercial buildings dominated by spandrel glass) not only translating into efficiency benefits but also enabling high-vision share as well. For such architectural insulation modules, VIPs are installed between two pieces of glass, forming a double-insulating glass unit.
VIP also offers freedom to achieve low U-values and meet window-to-wall ratio targets.
“This is an architectural product, or needs to behave like an architectural product,” said Yee.
Yet it also delivers on performance. VIP’s R-value numbers are meaningful, to say the least. VIP provides a per-inch R-value of between R-32 and R-35, according to material provided on the webinar. Compare that to mineral wool, for example, which comes in at R-4.2.
Other upsides that Yee pointed to include VIP’s moisture resistance, its thin profile (mineral wool must be between eight and 10 times thicker to deliver an equivalent R-value), and its inner core’s high degree of fire resistance.
As for disadvantages, VIP—which consists of the differentiating pressed fumed silica core along with a core bag and an aluminized multilayer barrier to contain vacuum and provide environmental protection—must be handled carefully because its seal cannot be broken; otherwise, the thermal properties will be severely reduced. In addition, VIP can’t be cut to size; panel customization is required.
If the goal is to be efficient and sustainable, hopefully such technologies can be used not just in new buildings. As Yee said, “The most sustainable thing we can do is not level [a building] but perhaps retrofit it.”
A case in point: a building in the U.K. that called for a façade retrofit without full replacement. The challenge was to maintain the aesthetic of an aging contemporary (yet historical) building while increasing the thermal performance, all in the context of prevailing space constraints. The solution found was a 17-millimeter VIP installed in glass spandrel.
In another scenario described, spandrel glass was used in the curtainwall of a contemporary building in the harsh climate of Alaska—a building that boasted dynamic natural light streaming through its glass. The application eliminated the need for thermal insulation on the interior.