"Smart" Alloy Could Make Cooling Systems 175% More Efficient

• thermoelastic refrigeration

If a new "smart" metal could help cool your home or refrigerate your food 175 percent more efficiently than current technology, imagine what that would do for your electric bills.

Department of Materials Science and Engineering (MSE) professors Ichiro Takeuchi and Manfred Wuttig have received a $500,000 Department of Energy (DOE) Advanced Research Projects Agency—Energy (ARPA-E) grant to develop a new "thermally elastic" metal alloy for use in advanced refrigeration and air conditioning systems. The technology promises far greater efficiency and reductions in greenhouse gas emissions.

Takeuchi and Wuttig have partnered with Dr. Frank Johnson and Dr. Ching-Jen Tang (General Electric Global Research) and MSE adjunct professor Dr. Jun Cui (Pacific Northwest National Laboratory) on the project.

"Air conditioning represents the largest share of home electric bills in the summer, so this new technology could have significant consumer impact, as well as an important environmental benefit," says Professor Eric Wachsman, director of the University of Maryland Energy Research Center (UMERC).

"[The team's] approach is expected to increase cooling efficiency 175 percent, reduce U.S. carbon dioxide emissions by 250 million metric tons per year, and replace liquid refrigerants that can cause environmental degradation in their own right," he adds.

Takeuchi, Wuttig and their colleagues have developed a solid coolant to take the place of fluids used in conventional refrigeration and air conditioning compressors. Their system represents a fundamental technological advance, they say.

In the next phase of research, the team will test the commercial viability of their smart metal for space cooling applications. The 0.01-ton prototype is intended to replace conventional vapor compression cooling technology. Instead of fluids, it uses a solid-state material—their thermoelastic shape memory alloy.

This two-state alloy alternately absorbs or creates heat in much the same way as a compressor-based system, but uses far less energy, the team explains. It also has a smaller operational footprint than conventional technology, and avoids the use of fluids with high global warming potential.

The team's ARPA-E grant—one of only 43 awarded nationwide and the first awarded to the University of Maryland—is part of a program designed to spur U.S. innovation by bringing "game-changing" technologies to market. The grants are funded with money from the federal American Recovery and Reinvestment Act, and stem from a recommendation contained in the 2006 National Academies report Rising Above the Gathering Storm, co-authored by University of Maryland President C.D. Mote, Jr.

"These grants are highly competitive and require a demonstration that the technology has genuine commercial potential," Wachsman explains. "This represents a significant investment in the state of Maryland and the development of its 'green' economy."

The solid-state, thermally elastic cooling technology was recently featured in the Popular Mechanics article "3 Next-Gen Air Conditioning Concepts." Read the story online »

Takeuchi, along with other ARPA-E grant winners, was also invited to attend an event hosted by Vice President Joe Biden.

Story adapted from the original University of Maryland press release by Neil Tickner.

Learn More:

Visit Professor Takeuchi's homepage »
Visit Professor Wuttig's homepage »

Published July 16, 2010