The HE team was a small, interdisciplinary team made up of scientists, development experts, engineers, geospatial analysts, user researchers and industrial designers who have long been passionate about the challenge of access to clean water. Drinking water access is often hindered by a range of complicated factors and structural challenges that vary from place to place, including proximity to existing water resources, local community infrastructure, governance issues and more. This is partially why in many places, piped water infrastructure could still be decades away.
Atmospheric water harvesters — devices which pull water from the air — have often been overlooked as a potential solution because of their relatively low outputs in comparison to other technologies, like desalination. One of their benefits, however, is that they can be built to be small, modular and renewably powered — decoupling them from some of the more systemic barriers to access. The team knew that such devices would never be the only solution needed, but their hope was that it could help fill a critical gap in places where safely managed drinking water was needed most.
To understand how the device worked, it’s helpful to go back to how condensation works in nature. When warm, humid air meets cooler air, or hits a cooler surface, the molecules in it slow down and cool into liquid. This is how clouds are formed in the atmosphere, or beads of water collect on a cold can of soda on a hot summer day. HE’s prototype basically replicated the natural process of condensation, but on a much smaller scale. This was made possible through a variety of processes and components — namely, constantly recirculating air, solar energy, and a desiccant (a material that absorbs moisture, like the silica gel packets you find in a new pair of shoes). The below illustration describes the process in more detail:
After various iterations and user research studies, the team eventually built their most recent prototype model. This prototype ran on solar heat and was made from vacuum-formed parts — a manufacturing technique typically used to make small, disposable items, like takeaway food containers. Light and low cost, the team realized vacuum-forming also had the potential to form many of the larger parts of their device too.
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