Engineering Innovation into Atmospheric Water Generation
At Clade, some of the most interesting engineering challenges come from applying heat pump technology in ways that go beyond conventional heating and cooling. Our work with Ahbstra is a good example.
Engineering water from air
Ahbstra has developed ARK™, an Atmospheric Water Generation system designed to produce drinking water from moisture in the air.
Designed to address water scarcity, ARK has been developed over seven years to be the first commercially available atmospheric water harvesting system using Metal-Organic Frameworks (MOF) technology, as opposed to conventional dew-point or dehumidification technology. It can generate up to 500 litres of water per day, delivering independent access to clean drinking water. The system is designed to operate in demanding environments and can continue producing water at relative humidity levels as low as 10%.
Clade’s role has been to engineer a bespoke heat pump and controls solution that forms a critical part of this process.
How does the system work?
Ambient air is drawn into ARK and passed through the MOF reactor, where the porous material captures water molecules from the air. Once the MOF has absorbed moisture, it needs to be regenerated so the water can be released. The Clade heat pump provides the heat required for this stage, producing heated air at approximately 80°C to release the captured water vapour.
The vapour is then cooled and condensed, with the heat pump also providing the cooling required for this part of the process.
The resulting water is collected and treated to produce drinking water.
This means the heat pump is involved in both sides of the thermal cycle: supplying heat for MOF regeneration and cooling for condensation.
Why was a bespoke heat pump needed?
This was not an application that could be met by simply selecting an off-the-shelf heat pump. The system had to operate as part of a highly specialised process, and we had to consider the thermal requirements of MOF regeneration, the temperature needed to release moisture, the cooling required for condensation and the interaction between each stage of the cycle.
The heat pump we designed and built is engineered around the specific requirements of the process. It uses R600a (isobutane) refrigerant, providing a low Global Warming Potential (GWP) solution for the thermal management of the system.
Bespoke controls for a bespoke process
Clade’s engineering contribution extends beyond the physical heat pump.
We developed and wrote our own controls specifically for ARK. These allow the heat pump to operate around the needs of the water-generation process rather than relying on a standard heat pump control strategy. This is important because the process is cyclical. The system captures moisture, regenerates the MOF, releases the water vapour, condenses it and then returns to adsorption.
Clade’s bespoke controls coordinate the heating and cooling cycles with the wider ARK process, helping the heat pump respond to the requirements of each stage.
This places Clade’s involvement well beyond equipment supply. We have provided an integrated heat pump and controls solution that forms part of the core technology within ARK.
Going beyond the norm
The Ahbstra project shows how heat pump engineering can be applied far beyond conventional space heating or hot water applications. Here, Clade’s technology is helping enable a completely different process: turning atmospheric moisture into drinking water. It’s exciting, innovative and delivers a solution to the increasing problem of water shortages in an increasingly hot world.