Here's the bad news: Even though the Earth is made up of around 71% water, 97% of it is undrinkable salt water, leaving just 3% fresh water. Two thirds of that is locked inside glaciers and polar ice caps. Our planet may be blue, but strangely enough that doesn't necessarily mean we have enough drinking water.
What with climate change, industry polluting our water with chemicals and a global population increase, scientists believe if nothing is done then, at our current rate of consumption, by the year 2025 we'll have pretty much no water left to drink at all. Predictably it's the third world countries who will be the first to suffer. And it's not like they're drowning in water right this moment.
So what's the good news? Well, AWGs, or Atmospheric Water Generators to give them their full name, are literally designed to extract water from the air around us. Even in the hottest deserts on Earth, there are water molecules in the air that can be filtered down into clean, drinkable water.
AWGs work very much like normal dehumidifiers, in that a compressor circulates refrigerant through a coil or chiller array before a fan pushes air over the water reaction area and condenses it into water. Dehumidifiers are used primarily to cool indoor environments whereas AWGs focus on extracting water for drinking, but they too can regulate room temperature.
Getting water from thin air has been practiced with varying degrees of success over the last 2000 years. We've all seen Ray Mears, Bear Grylls and other desert explorers making dips in the sand and laying a sheet of plastic over the top so that moisture will condense into water that'll drip down into a cup beneath the plastic.
These are called Air Wells and they've been tried in various shapes and forms throughout history, most notably by Russian Friedrich Zibold, Frenchman Leon Chaptal and Belgian Achille Knapen. Their attempts were low tech, involving huge piles of stones on the ground or buildings that had holes in the walls to let hot air pass through and cool on another wall inside.