Portal:Technology/Selected articles/54
An air well or aerial well is a structure or device that collects water by promoting the condensation of moisture from air.[1] Designs for air wells are many and varied, but the simplest designs are completely passive, require no external energy source and have few, if any, moving parts. Three principal designs are used for air wells: high mass, radiative and active. High-mass air wells were used in the early 20th century, but the approach failed.[2] From the late 20th century onwards, low-mass, radiative collectors proved to be much more successful.[2] Active collectors collect water in the same way as a dehumidifier; although the designs work well, they require an energy source, making them uneconomical except in special circumstances.