Abstract: A spray apparatus includes a pump, a reservoir and an atomizing unit in fluid communication within a fluid circuit. The atomizing unit comprises a housing enclosure defining an enclosed interior space. An aperture is defined a front wall of the housing, and an ultrasonic atomizer is disposed within the interior space proximate to the aperture. A fluid supply port extends into the interior space, arranged to deliver a fluid pumped by the pump to the ultrasonic atomizer. An overflow return port extends from the interior space, and is arranged to return fluid from the interior space to the reservoir. The fluid supply port may be arranged to deliver a fluid into a fluid receiving space such that the atomizer becomes at least partially immersed within a fluid during operation. Alternatively, the fluid supply port may be arranged to direct a stream of fluid against a surface of the atomizer.