Inspired by its work on the Empire State Building's 6,514 windows, Serious Materials has introduced a new product -- a window retrofitting system that can be installed in about 20 minutes.

Ian Sullivan, vice president and general manager of Serious Materials' SeriousWindows unit, says the new iWindow system allows companies to improve the energy efficiency of their building envelope in a fraction of the time and cost, using facilities staff rather than hiring an installation crew, and without displacing office workers while the job gets done -- all of which can bring down the cost of a window retrofit.

By how much? By 50 to 75 percent, according to the company, and in some cases by as much as 80 percent, according to Sullivan, who calls the savings potential "just massive."

Generally, a retrofit project involving the replacement of entire windows would "run north of $100 per square foot, before you blink," Sullivan said. "Just to replace the glass from single pane to dual pane, materials and labor are still going to run you a total $60, $70, perhaps even $80 a square foot depending on (labor costs) where you are doing the work." The return on investment for such retrofits typically exceeds five years.

In contrast, installation costs for the iWindow system is about $20 per square foot of the retrofit, according to the company. "It's simple to install, it's easy, low cost and non-disruptive," said Sullivan. "This is something the maintenance department can do."

The estimated return on investment for an iWindow system is five years or less, with the best ROI and greatest improvements in thermal performance occurring in older, single-paned, aluminum-framed wall systems, he said. Here are company's stats for iWindow performance in such a situation: "Improv(ed) full-frame R-value from R-0.8 up to R-3.9 (U-factor 1.2 to 0.25) and center of glass R-value from R-1.0 up to R-7.2 (U-factor of 1.0 to 0.14)."

An iWindow system is installed inside the building in the existing window frame (the top photo was taken during an installation). At its core is SeriousGlass, which has a spectrally selective suspended film system that is the key to the performance of SeriousWindows' products.

Based on measurements submitted by the customer, fully assembled iWindow panels made with SeriousGlass are shipped to the work site along with mounting tracks to hold each iWindow in place.

Installation consists of four key steps diagramed below -- (1) installing the mounting tracks in each window frame, (2) sliding the iWindow into the frame and onto the tracks, (3) screwing it in place, and (4) installing screw covers.

In the Empire State Building, Serious Materials retrofitted 6,514 double-paned, double-hung windows as part of the extensive greening project undertaken by owner Anthony Malkin, Johnson Controls and Jones Lang LaSalle in collaboration with the Clinton Climate Initiative and the Rocky Mountain Institute.

The company set up a mini-factory on a floor of the historic building, removed the windows, created super-insulated SeriousGlass units using the existing panes of glass and installed the retrofit product -- a sandwich of the original glass and advanced materials. All the work was done on site, with the most involved steps done at night to minimize work disruption for tenants.

The iWindow system shortcuts that process by several steps and makes the ones that remain easier for customers contend with, said Sullivan. "This is something as simple as popping the things in, going window by window and floor to floor," he said.

Why is the product called iWindow? As a shortcut for innovative window, apparently. Yet one can't help think the name is a sly salute to two famous game-changers -- Cupertino-based Apple, which like Sunnyvale-based Serious Materials is headquartered in California's Silicon Valley, and Microsoft.

Images courtesy of Serious Materials.