Atmospheric Water Harvesting from Low-Humid Regions of Hail City in Saudi Arabia

Abstract

Atmospheric water harvesting (AWH) is emerging as a promising technique of water production in remote and isolated areas away from natural water resources. The present study describes potential of the AWH from low-humid regions under the climatic conditions of Hail city (27.64° N, 41.75° E) in Saudi Arabia. Trapezoidal prism solar still of 5-shelves is developed, where the shelves are filled with black cotton cloth bed saturated with calcium chloride solution. The solar still is opened during night hours, enabling the descant to absorb humidity from humid air (absorption process) and closed during day hours causing desorption of water under higher temperatures (regeneration process). The vapor condensates on a glass surface and is collected in a bottle. Under low-humid conditions of the Hail city, the desiccant balanced approximately at 48% saturation concentration. The water production of the device reaches 1.06 l/m2day by consuming 22.96 MJ solar energy/l of water with a cost of $0.055 per liter. The present study has demonstrated high potential of the AWH technique from low-humid regions up to 26.5%. The proposed device is standalone with promising performance, which needs neither the natural water resources nor the infrastructure. The device is suitable for remote and isolated small communities.