Technology

Better compression for a lasting impression

 By RP Siegel

A Delaware company called Xergy is working with GE to market a new type of electro-chemical compressor that could replace conventional mechanical vapor compression systems at roughly 25% higher efficiency. These could be used across a broad range of HVAC systems, not only saving energy but also eliminating the need for the fluorocarbon refrigerants that are harmful, both to the ozone layer and to the climate. The first application will be for a heat pump water heater. Tony Bouza, Technology Manager for HVAC, Water Heating, and Appliances at DOE’s Building Technologies Office (BTO) said, “Electrochemical compression has the potential to truly transform the market away from today’s vapor compression solutions. This the Apple 1 of electro-chemical compressor technology…”

Major home appliances such as washers, dryers, refrigerators, dishwashers and air conditioners use a great deal of energy — especially when you consider the addition of hot water. Much work has been done to improve the efficiency of these devices, through careful design, improved motors, fans and other components, along with smart controls.

A new technology called electro-chemical compression (ECC) developed by a Delaware company called Xergy, promises some potentially major impacts across this space. The technology can replace the conventional compressors used in the mechanical vapor-compression systems found in refrigerators, air conditioners and heat pumps. Instead of using a motor to drive the compressor, it relies on an electro-chemical process not unlike that used in a fuel cell.

Each cell has two electrodes, an anode and a cathode. When hydrogen gas at the anode hits a catalyst layer, it splits off a proton and an electron. When it re-forms back into hydrogen at the cathode, it does so at a higher pressure. The compressed hydrogen, along with water vapor, can then be used as a highly efficient refrigerant, which is compressed and then expanded, picking up heat in the expanded state and the giving heat off when condensed, just like conventional refrigeration systems.

The difference is, this compressor, and indeed the entire system, has no moving parts. According to Bamdad Bahar, Xergy’s President, this type of compressor is 20-30% more efficient than the mechanical type, which is huge considering the millions of them that are out there.

Commenting on Xergy’s delivery of a working system, Tony Bouza, Technology Manager for HVAC, Water Heating, and Appliances at DOE’s Building Technologies Office (BTO), who helped support the development, said, “If you’re not in the heating and cooling technology industry, it may be hard to appreciate the significance of this milestone. Electrochemical compression has the potential to truly transform the market away from today’s vapor compression solutions. This prototype is the Apple I of ECC technology.”

According to DOE, annual energy savings from widespread adoption of the technology in the water heating market could total 1 Quad, equal to the electricity used by 28 million homes in a year

Another benefit of great importance is the elimination of hazardous refrigerants.

In 2011, the company entered the GE Ecomagination Challenge as a leading edge technology and won. Says Bahar, “the first application they [GE] suggested was this hybrid hot water heater for residential use.”

Heat pump water heaters are relatively new to the market, boasting higher efficiency at a somewhat higher cost compared with conventional gas or electric systems. But new ECC-based water heaters will be far more efficient, and quieter.

According to DOE, annual energy savings from widespread adoption of the technology in the water heating market could total 1 Quad, equal to the electricity used by 28 million homes in a year.

“It’s no longer a matter of if,” says Bahar, “but when, this technology will enter the market. We’ve proven that electrochemical compression is a viable alternative to traditional water heater technologies. Now it’s just a matter of refinement to get the package smaller and cheaper so that it can see widespread adoption in the U.S. residential market.”

After that, it’s only a matter of time until these compressors begin to show up in refrigerators and air conditioners, bringing even greater energy savings to the world.

about the author
RP Siegel
Skilled writer. Technology, sustainability, engineering, energy, renewables, solar, wind, poverty, water, food. Studied both English Lit.and Engineering at university level. Inventor.