Experts from the U.S. Department of Energy’s (DOE) associated research organizations discussed energy-saving tactics, such as emerging technologies for highly efficient windows and building envelopes, at the meeting of the Window and Door Manufacturers Association (WDMA) held last week in Minneapolis.

“The purpose of the meeting was to present the latest information on the program’s goals, research agenda and current R&D activities, while receiving feedback from stakeholders on program needs and priorities,” said Walt Zalis, market transformation lead for Energetics Inc.

Alexis Abramson, emerging technologies supervisor for the DOE’s Building Technologies Program, was first to speak during the session, providing an update on the program, which partly focuses on developing window technologies in order to push them to the market.

The program prioritizes research, development and marketing investments in new and existing technologies by estimating “potential energy savings and costs of conserved energy,” she said.

The program also deals with the building envelope and its energy consumption. According to Marc LaFrance, DOE technology development manager for the program, building envelopes have an impact on building energy consumption sectors such as ventilation, water heating and lighting. About 133 billion is spent per year on buildings’ energy consumption, which is 13.9 percent of U.S. energy.

LaFrance said the program intends to “develop a cost-effective R-10 window and bring dynamic insulation with more than 20 percent peak load reduction” to markets.

He said for current technologies in windows (residential and commercial), roofs, walls, infiltration and foundations have ready-now technologies available to save energy. He added, however, that “enabling research can help” consumers access more efficient products in the future—such as shifting from simple daylighting and window-to-wall ratio strategies in commercial buildings to utilizing dynamic windows and light redirection technologies.

“The U.S. had initiated unprecedented investment in envelope and window research, this will decline sharply, and could end up with less than 25 percent labor buying power compared to 2002,” LaFrance said. “New technology will be essential to achieve low carbon, low energy buildings, and to develop more affordable solutions for the existing building stock.”

Dan Gaspar, technical group manager for the Materials Chemistry and Surface Research Group in the Energy and Efficiency Division at Pacific Northwest National Laboratory (PNNL), discussed the organization’s efforts in windows technology development and deployment.

According to Gaspar, PNNL has recently been researching developing technologies for daylighting and vacuum insulated glass (VIG) products. With new advancements in window coatings for daylighting, he says light can be redirected to different points of a room, which increases the naturally lit area and eases reliance on electric lighting.

“The objective is to develop window coatings that allow double daylight penetration into buildings to save energy,” Gaspar says. “The next steps are to demonstrate the proof of the concept and to optimize performance.”

Gaspar says that VIG glazing research has consisted of “developing materials and techniques to produce low-cost, durable and highly insulating evacuated glazing.”

He says there have been challenges in regards to transparency, standoffs, edge seals, assembly, evacuation and longevity of the glazing products but thus far PNNL researchers have produced VIG prototypes.

National Renewable Energy Laboratory (NREL) research scientist, Robert Tenent, provided an update on the organization’s windows program, which he says consists of experts specializing in building technologies, chemical and materials science, technology transfer and strategic energy analysis.

According to Tenent, NREL conducts “research and support to mitigate the risk associated with the development of improved fenestration solutions.”

He said, there are four sectors supporting window product development, which include “[energy efficient building] modeling, development of improved materials, low-cost manufacturing process development, and advanced fenestration testing.”

Additionally, Tenet said NREL is focusing on electrochromic dynamic windows that act similarly to lithium ion batteries and can change color if charged and discharged. The improved materials for this product include faster switching speeds; enhancements in color; and advances in film durability and thickness.

Stephen Selkowitz, group leader for the Windows and Envelope Materials Group of the Building Technologies Department at Lawrence Berkeley National Lab (LBNL), discussed the organization’s current activities in regards to window technologies.

“[LBNL’s] multi-year goals are to develop energy‐efficient dynamic windows of the future in collaboration with industry partners, improve performance and cost effectiveness of the most advanced concepts of dynamic windows, and to provide market-viable solutions for advanced materials, and coatings and device fabrication processes,” Selkowitz said. (For more from Selkowitz, see related story).

Pathways to reaching net zero, according to Selkowitz, can be broken in two parts: Increasing the rate of adoption of existing or emerging technologies such as utilizing low-E glazing everywhere and developing new technological options.

The four big areas in terms of steps to take include highly insulating systems, dynamic glazing for solar control, daylighting and air flow. Advanced glazing systems even could become net energy producers, he said.

“If you use the right windows, you get happy people and more efficient buildings,” Selkowitz said. “If you step back and look at how things move, we tend to overestimate the speed at which we move but underestimate the impact we’ve made.”

by Erica Terrini,

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