Be cool for less - cheaper refrigeration technology

Researchers at the University of Maryland are developing a 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.

The Maryland team will soon begin testing of a prototype system, with economic stimulus funding from the US Department of Energy.

"The approach is expected to increase cooling efficiency 175%, reduce US carbon dioxide emissions by 250 million metric tons per year, and replace liquid refrigerants that can cause environmental degradation in their own right," says Eric Wachsman, director of the University of Maryland Energy Research Center (UMERC).

The lead researchers on the project, Ichiro Takeuchi, Manfred Wuttig and Jun Cui, materials science engineers in Maryland's A James Clark School of Engineering, 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 now test the commercial viability of their smart metal for space cooling applications. The 0.01-ton prototype is intended to replace conventional vapour 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 Maryland team explains. Also, it has a smaller operational footprint than conventional technology, and avoids the use of fluids with high global warming potential.

General Electric Global Research and the Pacific Northwest National Laboratory are partnering with the University of Maryland on the project.