Design and Build of an Atmospheric Water Generator

What it does

Water scarcity will be a top priority in the upcoming decade. Our design project involves the development of a working Atmospheric Water Generator prototype to produce an adequate supply of drinking water for the average person within developing countries.

Your inspiration

Our team of highly motivated chemical engineering students at the University of Waterloo are very interested in sustainable technologies and entrepreneurial innovation. For our capstone design project we have wanted to tackle a current global issue such as the problem of global water scarcity. The United Nations has stated that water scarcity will be a top priority in upcoming decades and based on the fact that current strategies such as desalination and the use of water wells have their multiple drawbacks, our team strongly believes there is a dire need for an alternative cost-efficient technology to alleviate this burden.

How it works

Atmospheric water generation is the process of the collection of water through cooling warm, humid air leading to the condensation and separation of the water vapour. Our solution involves the use of a Peltier device to perform this condensation. The Peltier device is a thermoelectric cooler: by running a current through two different conducting materials a temperature gradient is generated leading to the exposure of a Cold Side and the Hot Side. By taking advantage of this effect, we can use the cold side as our condensing surface and build an air multiplication system around the hot side to reject the waste heat as fast as possible. Based on various iterations with regards to the optimisation of our working lab prototype, our unit was found to be capable of producing up to 3L of drinking water within a 24 hour period, meeting the outlined project objectives. Our next steps involve additional optimisation strategies for the production of 40L of potable water.

Design process

The experiment was set up to allow testing in a closed system while manipulating the variables of humidity and ambient temperature to maximise water production. The apparatus involved the use of a closed environmental chamber, in which the prototype was placed inside. Water vapour was fed into the system at a controlled constant flux to mimic atmospheric climate conditions. Using a constant 12 V power supply the prototype was placed under operation for a period of 1 hour. The monitoring equipment involved the use of a hygrometer for measuring ambient temperature and relative humidity, as well as thermocouples for measuring the temperatures of each side of the Peltier device. This allowed us to collect data and determine experimental observations with regards to optimisation of the prototype. A total of 4 prototype configurations were achieved during the research and development phase of our capstone project. Each successive prototype involved configuration updates to improve the heat rejection and surface area properties by incorporating fans, fins and a closed-vacuum closed chamber for optimal heat rejection, and drop-wise condensation. A 5th and final prototype was designed to incorporate the addition of a blade-less fan model for potential generation of up to 40 L/day.

How it is different

Current strategies involve desalination as well as the use of water wells. However, these methods have their drawbacks where desalination is an energy intensive process with produces a lot of brine waste by-product and water wells suffer from contamination issues which arise due to long aquifer replenishment times. An alternative source involves the water present within the air, a global volume equivalent to 11 billion Olympic sized swimming pools. Our technology combines the novel aspects of the Peltier device as well as the blade-less fan together, optimised through chemical engineering concepts developed through our undergraduate experience to produce an extremely cheap product within a noncompetitive market. Our unique solution of an Atmospheric Water Generator using Peltier condensation is a truly evolutionary and unique innovation that has the potential to make a dramatic impact for developing countries around the world.

Future plans

In addition to our accomplished work, a 5th prototype has been designed through the incorporation of a blade-less fan and a larger scaled unit to advance our project scope in order to meet the daily average water requirements for a household in a developing region. Additional strategies involve the use of solar power to reduce operational costs. Next steps involve working with local governments and not-for-profit organisations to conduct on the ground testing. Further analysis will be conducted with regards to filtration and mineralisation for human consumption.

Awards

1) Norman Esch Entrepreneurship Award 2) Engineer of the Future Trust Fund 3) GM Innovation Award for Chemical Engineering