Vacuum Bubbling introduces the background and applications for generating bubbles under a vacuum condition, accomplished through depressurization without the need to heat water. It presents the advantage of utilizing vapor bubble in deaeration applications because the diffusion for degassing happens between the water body and micro vapor bubbles without the need of membrane or packing. Instead of relying on massive heating, vacuum bubbling focuses on depressurization down to the level of saturated vapor pressure or below to secure vapor bubbles with virtually zero dissolved non-condensable gases, including oxygen. The book considers prospective applications, such as extracting high-oxygen-content air from water for underwater breathing, pretreatment of aircraft fuel before being pumped into a fuel tank system, and probable desalination applications through massive bubbling combined with low-grade renewable energy. The book is intended for researchers in thermal fluids, heat and mass transfer, process engineering, and water treatment fields and industry professionals working in power generation, plant and process engineering, transportation, and energy.