Powering Glass To Do Double Duty

Colorado company developing windows that heat and insulate, providing new opportunity for increased energy savings
By Jenni Chase, Editor, Glass Magazine
August 11, 2010

With increased interest in energy efficient windows, Radiant Glass Industries is throwing its hat in the ring with Power*e glass, a radiant-heat window technology that heats and insulates home interiors. The Denver-based company has installed the glass in about a dozen projects.

Offering the appearance of a standard double-pane IG unit, the Radiant glass produces heat, while reducing energy consumption from 35 to 40 percent compared to traditional alternatives, such as forced air natural gas, says Gino Figurelli, RGI product development.

Nineteen of 33 windows in the Keystone House, an RGI pilot project in Colorado’s Rocky Mountains, incorporate Power*e glass. Using the windows as the primary heat source for the 2,800-square-foot home has reduced the heating costs by half, the company reports.

“By adding an efficient heat source such as Power*e glass, [homeowners] will reduce their reliance on conventional heating because the radiant heat works to distribute heat throughout the room and its objects for improved comfort with reduced power usage,” says Larry Johnson, executive vice president, Edgetech I.G., whose SuperSpacer is part of the Power*e glass window design.“The fact that Radiant Glass Industries’ IG is efficient and durable to begin with [means] heat loss through the window is minimal.”

Power*e units incorporate Pilkington TEC-15 tempered low-E glass on the interior in combination with any tempered clear, tinted, patterned or opaque glass option on the exterior. The units also feature two bus bars or conductors, and a stainless steel retainer. The windows produce heat via a low-voltage current that runs across the metallic coating on the interior of the glass, resulting in a uniformly heated surface capable of reaching temperatures between 60°F up to 140°F depending on the application. Safe to the touch, the heated windows utilize temperature controllers and thermostats. All electrical heating components are sealed within the unit, except for electrical and control wires that extend from one corner.

It is these electrical wires that intimidate some dealers and installers, but they do not pose a problem for installation, Figurelli says. “The electrical components in the window don’t greatly affect how they glaze in the window frames because the controllers don’t go in the frames and usually are located where the homes electrical panels are, they can be placed in the basement or closet if needed.

At this phase in the product’s development, an RGI-trained technician takes over the electrical configuration after the Power*e glass is in the window frame. “We would make terminations to the wires at the window, and commission the project, explain to the customer how the system works, etc.," notes Figurelli. "Any window company can install Power*e glass into the frames, and we'll handle it from there.”

The window’s electrical components should not discourage window manufacturers looking to add Power*e glass to their product lines, Figurelli adds. Window manufacturers can easily and inexpensively dedicate a small portion of their facility to manually adding the heated glass, he reports. “What I would suggest, is they look at it like a value-added product. Tempered glass, coated glasses are very common, so there is no change there. We're just adding a few simple components. We will also work with manufacturers to provide automated solutions.

“The biggest benefit that Power*e glass offers is human comfort,” says Radian't Gino Figurelli. As these pictures demonstrate, the windows can maintain a comfortable interior environment even when temperatures outside drop well below freezing.

Applications and availability
RGI foresees the glass being used in both residential and commercial windows, as well as glass walls and interior partitions. Figurelli expects demand to increase as product awareness and the need for energy efficient window options grow. “Right now, we’re targeting residential and commercial applications,” he says. “We think that the impact for providing the best level of human comfort during the winter months would suit these markets”

Power*e glass units currently are available through RGI and its sister company, Busick Insulated Glass Inc., also located in Denver. Dealers must provide window shape and size specifications so the company can calculate power requirements for the home, prior to window fabrication, Figurelli explains. “We can then tell the dealer if the customer needs to upgrade their electrical service.

”Homeowners who invest in radiant-heated windows from RGI are essentially making an investment in their future,” says Edgetech’s Johnson. “The energy savings will be exceptional, enabling them to save on energy bills and do their part to protect the environment.”