Elastic Metal Alloy Refrigerants

Elastic Metal Alloy Refrigerants

College Park, Maryland
Project Term:
10/01/2010 - 03/06/2017

Critical Need:

New and more efficient cooling methods are needed to reduce building energy consumption and environmental impact. Residential and commercial buildings currently account for 72% of the nation's electricity use and 40% of our carbon dioxide (CO2) emissions each year, 5% of which comes directly from air conditioning. In addition, the typical refrigerants used in air conditioners are potent greenhouse gases (GHGs) that may contribute to global climate change. Because the majority of cooling systems run on electricity, and most U.S. electricity comes from coal-fired power plants which produce CO2, there is a pressing need to support improvements that increase the efficiency of these technologies and reduce the use of GHG refrigerants.

Project Innovation + Advantages:

The University of Maryland (UMD) is developing an energy-efficient cooling system that eliminates the need for synthetic refrigerants that harm the environment. More than 90% of the cooling and refrigeration systems in the U.S. today use vapor compression systems which rely on liquid to vapor phase transformation of synthetic refrigerants to absorb or release heat. Thermoelastic cooling systems, however, use a solid-state material—an elastic shape memory metal alloy—as a refrigerant and a solid to solid phase transformation to absorb or release heat. UMD is developing and testing shape memory alloys and a cooling device that alternately absorbs or creates heat in much the same way as a vapor compression system, but with significantly less energy and a smaller operational footprint.

Potential Impact:

If successful, the UMD's technology could help displace traditional cooling systems that rely on polluting refrigerants.


Increased energy efficiency would decrease U.S. energy demand and reduce reliance on fossil fuels—strengthening U.S. energy security.


Eliminating refrigerants with polluting emissions could account for up to 10%-20% of global warming by year 2050. UMD's technology could eliminate the use of these refrigerants.


Widespread adoption of this technology could increase energy efficiency of air conditioners and refrigerators—providing consumers with cost savings on energy bills.


ARPA-E Program Director:
Dr. Christopher Atkinson
Project Contact:
Prof. Ichiro Takeuchi
Press and General Inquiries Email:
Project Contact Email:


United Technologies Research Center

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