In this Letter, we present an electrohydrodynamic atomization (EHDA) technology that generates and delivers charge reduced nanoparticles to open space without a collector electrode. The backward ring-nozzle ac EHDA system driven at sub-kHz frequencies generates alternatively charged particles, which exert electric force and recombine in the vicinity of the spraying electrode. This unique configuration creates a stable jet stream of charge reduced nanoparticles, contrary to classical dc EHDA systems. Experiments indicate that nanoparticles are emitted through a wide range of voltages and frequencies, matching up to the hydrodynamic time of the cone jet model. These unique advantages of the new system would empower the nanoparticle EHDA devices for aerosol drug delivery in bio and health care applications.