Stulz of North America, Inc.'s (Frederick, MD) ultrasonic humidifiers are designed to operate at 93% less electrical energy as compared to electrode boiler or infrared systems. Ultrasonic operation is based on generating mechanical energy via a piezoelectric transducer. This energy creates a cavitation in water; vapor droplets are formed, forced to the surface, and fine droplets are then quickly dissipated in the air, says the manufacturer. Unlike other systems, no heating or boiling is involved; rather, a cooling effect is generated, further reducing energy consumption in year-round cooling applications, it says.