Design of an atmospheric water generator: Harvesting water out of thin air

Abstract

Water scarcity affects 1.2 billion people on a global scale, representing nearly one fifth of the human population. In some regions, current water sources are being depleted faster than they are renewed and the majority of this depletion is being used for irrigation and agricultural purposes. At any given time, the atmosphere contains 3400 trillion gallons of water vapor, which would be enough to cover the entire Earth in 1 inch of water. Herein, we describe the design of an innovative solution to water scarcity in regions with medium to high humidity - Atmospheric Water Generators (AWG). This device converts water vapor into liquid water and is designed for agricultural and irrigation purposes in regions where water scarcity exists. More specifically, two AWG concepts were developed by our team, one utilizing Peltier devices and the other a heat exchanger, in order to allow multiple design alternatives to be considered. The Peltier-based concept works by applying current to induce a temperature gradient in order to cool and condense the surrounding air. The heat exchanger concept works by cycling a coolant that is cooled by a lower ground temperature. Both AWG concepts were designed utilizing sustainable engineering principles to minimize energy consumption and cost (particularly when compared to AWGs currently on the market). The designs are estimated to create enough water daily to grow 2 fruit trees (1 gallon a week) at an example test condition of 60% relative humidity and 85°F.