NEWS

PARC has developed a proprietary thermoacoustic refrigeration technology that can achieve double the efficiency of the best current residential and commercial air conditioning and refrigeration systems.

Cooling applications represent 25% of all electricity use in the United States, consuming over 7 quadrillion BTUs of energy and generating nearly 600 million metric tons of CO2 emissions annually.

The predominant technology for air conditioning, the vapor-compression cycle, despite its maturity and ubiquity, can reach efficiencies of only 12% of the theoretical maximum. Achieving significant energy savings and CO2 emission reductions requires a fundamentally different approach to cooling.

PARC has developed a technique to enable thermoacoustic cooling technology for air conditioning applications. Wide adoption of PARC's technology could lead to dramatic energy savings and greatly reduced CO2 emissions. PARC's approach could:

• Double the efficiency of air conditioning
• Save 4 quadrillion BTUs (13% of total U.S. electricity use) per year
• Reduce CO2 emissions by 311 million metric tons annually

How does it work? Gases are inserted into a tube filled with mesh membranes called regenerators. As the sound wave passes through the regenerators, a low-pressure, low-temperature/high-pressure, high-temperature gradient begins to form. One end gets hot while the other gets cool. Heat exchangers can then be used to extract and exploit the heat or cooling power

While thermoacoustic refrigeration is a well-established technology for cryogenic cooling, it has not been effectively applied at room temperature due to limitations of current techniques. Overcoming this deficiency with a novel acoustic power-recovery technique, PARC's design can achieve a coefficient of performance (a standard measure of air conditioner efficiency) of 9-more than double that of today's best vapor compression systems.

If widely deployed in the U.S., the technology could reduce energy consumption for cooling from 7 BTUS to 4 BTUs, which translates to a 13 percent reduction of electricity consumption in the U.S., according to PARC.PARC is currently building prototype systems, and will have a full-scale demonstration unit within a year.

It is seeking strong commercialization partners who have deep market penetration in the air-conditioning or refrigeration industry or who are interested in displacing current cooling approaches.

Like some other green projects at PARC, the thermoacoustic coupler can be traced back to printers and copiers.  (This place used to be Xerox's internal lab before it got spun out as an independent subsidiary in 2002. It's where the PC was invented.)

PARC had once conducted research on exploiting sound waves to focus ink-jet droplets, said Elrod. The idea was to develop photo quality imaging. Although promising, Xerox did not commercialize the technology.

Research on controlling toner powder has lead to a spiral that could one day be used in water purification or separating algae from water to make biofuel

A global center for commercial innovation, PARC (Palo Alto Research Center, Inc.) works closely with enterprises, entrepreneurs, government program partners and other clients to discover, develop, and deliver new business opportunities. Previously known as "Xerox PARC." PARC was incorporated in 2002 as a wholly owned subsidiary of Xerox Corporation. For more information about PARC please visit www.parc.com.

See also "Can-sound-waves-whack-power-consumption"