Thermoacoustic engines, or acoustic heat engines,are energy-conversion devices that achieve simplicity and concomitant reliability by use of acoustic technology. Their efficiency can be a substantial fraction of Carnot's efficiency. In the rnoacoustic prime movers, heat flow from a high-temperature source to a low-temperature sink generates acoustic power(which may be converted to electric power using a transducer).In thermoacoustic heat pumps and refrigerators,acoustic powe r is used to pump heat from a low- temperature source to a high-temperature sink.

Our Thermoaacoustic Refrigerator consists of an air-filled resonator,a loud speaker, a stack of plates, and two heat ex changers.When deiving the speaker with an acoustic power of 0.628W at 600Hz, the temperature of the cold-exchanger drops to -24.5C, and it takes 9 minutes to reach a value of 63% of the final temperature difference.