Harvesting water out the ambient air is not very complicated. In fact, it is rather simple.
There are three ways to gain the water out of the air:
1. Condensation. The systems cools the ambient air below the dewpoint. The water vapor in the air will condensate. Gather the condensated water. Filter the water it and you have drinking water. When the temperature of the air is high and so is the relative humidity, the air per cubic meter air contains more water compared with cold and dry air. The factors relative humidity and temperature determines the dew point. In oother words, the climate circumstaces determine s the quantity of the required energy to cool the system enough. That is why in the humid tropical aereas this way of harvesting water out of the air works best against the cheapest price per liter produced drinking water.
2. Absorption. There are materials which have the property that they atract water out of the air. And when you heat that material the water escapes the material as water vapor again. When this water vapor condensates against a colder surface, one can gather this water. A good example is Silica Gel. This principle is not depending temperature.
3. Fog nets. These fog nets works only under special circumstances. It needs an up going humid foggy air stream against a slope of a mountain. These fog nets catches the water in their nets. Just like a spider net does.