The concept of getting water from air is not a new one; evidence of fog and dew collection systems have been found in ancient civilizations in South America and the Middle East. Several man-made devices such as antique stone piles in Ukraine, medieval “dew ponds” in southern England or volcanic stone covers on the fields of Lanzarote have all been thought to be possible dew-catching devices.
Gleaning water from the air follows well-known laws of chemistry and physics, namely via a process known as condensation – atmospheric water vapour from the air naturally condenses on cold surfaces into droplets of liquid water known as dew.
There are essentially two types of air to water devices; machines that operate by condensation of water vapour on a lower temperature surface and devices that use a concentrated brine solution to absorb the water vapour, which is then evaporated and condensed in a later step.
Condensation systems are basically like dehumidifiers; a fairly standard air to water system consists of a particulate filter for incoming air, evaporator/condenser, purification system including cartridges and disinfection (UV), a collection tank, storage tank, cold storage tank and a tap.
While methods differ slightly from device to device, the basic premise is simply taking advantage of water vapour in the atmosphere to harvest clean and potable water through condensation on a cold surface, a passive process that allows water particles to return to the earth in a pure form.
Vapour is gathered on fog nets or in other receptacles, condensed into a collection tank; the water is then cleaned of all contaminants such as dust, bacteria, viruses, microbial components, and other contaminants to make it safe for drinking, and then transferred into storage tanks. Cleaning generally consists of some type of disinfectant as well as filters to remove particulates and dissolved chemicals. Ultraviolet (UV) light disinfection is also sometimes utilised to disinfect the water.