I'm working on a project with several others to create a flying device much like a blimp, but smaller and more agile. Our method of life is eighther a light gas like helium or preferablly, a Vacuum system that ajusts the % of vacuum inside a set space to provide lift and control decent. The system itself has been planned and construction has began, but for our computer guidance sytem I need to know exactlly how much lift a Square foot of Vacuum can provide so we don't end up crahing. Does anyone know the figure or the equation to find it. I've seached, but have always been directed to scuba sites. Please help.