The emergence of acoustic compressors has been made possible by the development of a new technology called Resonant MacroSonic Synthesis (RMS). RMS allows the creation of macrosonic standing waves in acoustic resonators. The shape of the resonator controls the nonlinear fluid dynamic processes by which energy is transferred to higher harmonics. Through this process resonators have been designed that allow high-amplitude shock-free waveforms. A variable reluctance driver is used to transfer energy into the resonator. The entire resonator is oscillated along its axis at the fundamental acoustic resonance frequency. This process is called entire resonator drive. The valve technology used in these compressors is similar to that of conventional reciprocating compressors. Acoustic compressors are inherently variable capacity and oil-free. Other unique characteristics are flexible orientation and low profile packaging option. Development focuses on vapor-compression applications. The application discussed here is spot-cooling.