They were typically found on desert planets such as Tatooine where water was scarce. Moisture farmers collected water using moisture vaporators for sale or for use in hydroponic gardens. Owen Lars, for example, was a moisture farmer.
Moisture vaporators were relatively tall and slender devices, used to harvest water from a planet's atmosphere. Costing up to 500 credits, moisture vaporators came in various different models, and could reach up to 3.5 meters in height. The devices were stationed at ground level and coaxed moisture from the air by means of refrigerated condensers, or chilling bars, which generated low-energy ionization fields. Captured water was then pumped or gravity-directed into a storage cistern, which adjusted its PH levels. Vaporators were capable of collecting 1.5 litres of water per day, even when the relative humidity of the air was only 1.5 percent. Higher-end models, such as those manufactured by Pretormin Environmental, were equipped with computers, which could adjust the strength of the ionization and refrigeration fields to compensate for changing wind speed and temperature. Patch-in droid units were used for communication with the binary brain unit of moisture vaporators, and could also interface with external droids. [Source: wikia]
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