Embodiments of the invention include a system and a method for purifying and storing water produced from atmospheric air to provide a safe, inexpensive source of potable water. Improvements over prior systems and methods include the use of two isolated air chambers, one for ambient air used to capture moisture from the atmosphere, and another for clean rechargeable air to convert the captured moisture into condensate and using a rotating mass of hygroscopic material and a condensation unit, each of which is periodically sterilized by heat.