Solar humidification

The Solar Humidification-Dehumidification-Method (HDH) is a thermal desalination method. It is based on evaporation of sea water or brackish water and consecutive condensation of the generated humid air, mostly at ambient pressure. This process mimics the natural water cycle, but over a much shorter timeframe. The most simple configuration of that technology is the solar still, evaporating the sea water inside a glass covered box and condensing the humidity on the lower side of the glass cover.

More sophisticated designs separate the solar heat gain section from the evaporation-condensation chamber.

An optimized design comprises separated evaporation and condensation sections. A significant part of the heat consumed for evaporation can be regained during condensation. An example for such an optimized thermal desalination cycle is the Multiple-Effect-Humidification-Method (MEH).