New Invention for Energy-Efficient Steel Framing

A primary weakness of light-gauge steel framing for houses has been its severely compromised thermal integrity. In general, the simplest way to get a steel-framed wall to perform like a 2x6 wood-stud wall is to use 2x4 steel studs and add 2” (50 mm) of insulating foam sheathing. Now, researchers at Oak Ridge National Lab (ORNL) are seeking a patent on an invention that accomplishes the same thermal integrity with a lot less foam insulation (and presumably less expense).

Most details about the new “studsnuggler” are still under wraps, but the lab’s parent company, Lockheed Martin Energy Research Corp., has released a general description in hopes of identifying parties interested in licensing and commercializing the product. Essentially, the studsnuggler is a “foam C-shaped profile” that fits around and insulates each steel stud individually rather than the total wall area. The foam also extends beyond the studs by two inches, so that a 2x4 steel stud creates a 51⁄2” (140 mm) wall cavity, like a 2x6 stud. The end result, according to Jeff Christian, one of the product’s inventors, is a steel-and-foam combination that performs comparably to a 2x6 wood stud.

According to Christian, a steel-framed 2x6 wall insulated only with batts has an R-value of about 7.4 (RSI-1.3) at the clear wall area (not accounting for additional losses due to added framing at rough openings and corners). The same wall fitted with studsnugglers attains a clear wall area R-value of 16.3 (RSI-2.9). It isn’t clear how this new product would be detailed at problem areas such as corners and rough openings and how energy performance would be affected, but given the attention ORNL researchers have paid to that subject in recent years, it’s likely that they have addressed such areas effectively.