Atmospheric Water Generator

Author: Subham Sarraf ,BME 074

An atmospheric water generator (AWG) is a device that extracts water from atmosphere. Water vapor in the air can be extracted by condensation – cooling the air below its dew point, exposing the air to desiccants (drying agent: calcium chloride), or pressurizing the air. Unlike a dehumidifier, an AWG is designed to extract the water potable. AWGs are useful where pure drinking water is difficult or impossible to obtain, because there is almost always a small amount of water in the air that can be extracted. The two primary techniques in use are cooling and desiccants. 
Clean drinking water is essential to the existence of life. Currently, more than 1 billion people, ONE out of every SIX people on the planet, don’t have access to clean drinking water. Even though our earth is covered by water, appearing plentiful, of all our natural resources, water has become the most precious and the most needed. Over the years, global environmental groups around the world have consistently reported on the dangerous quality of the planet’s limited water supplies – supplies that are continually being degraded. The effects of global warming and the increase in global population with the attendant increase in water usage have only made the problem more severe. 
Back in year 2009, Arye Kohavi Israeli entrepreneur and former combat commander, and a team of engineers first introduced concept of atmospheric water generator to provide easily accessible water to the military around the world, called Watergen (name of company). Then later in 2016, this company shifted its focus tackling water scarcity and answering the needs of civilians following natural disasters. In following years, they developed a line of products, suitable for different needs, from remote rural areas to commercial office buildings and private homes. Watergen is an Israel-based global company, headquarter is in Petach Tikva, Israel. It uses heat exchange and cooling process to extract water from atmosphere and multi-stage filtering system to remove impurities, and minerals to make it portable for drinking. Similarly, alike this Company, many other company have establish to provide fresh drinking water from air, some of them are Quench Innovation, Infinite water, and Drinkable Air. 
Here Solar-driven atmospheric water generator is one of the process to harvest water from atmosphere, which is based on adsorption-desorption process. In this process, sorbent absorbs atmospheric water, desorbs under the sunlight to generate vapor, which condenses into liquid water. From demonstration, Metal-organic framework (MOF) material as solid sorbent can produce 1.2 kg m-2 d-1 water, and calcium chloride (CaCl2) solution as liquid sorbent to get evaporated water of 2.32 kg m-2 d-1. 
We all have a role to play in reducing the impact our water consumption has on this water-scarce planet. It is imperative that, as a society, we invest in technologies that will provide for the future of pure drinking water for all citizens of the world. As one of those technologies, Atmospheric Water Generators (AWG) harvest fresh great tasting water from air. Most people have no idea how much water is readily available in Earth’s atmosphere – there is over 3,100 cubic miles of water, or more than 3.4 quadrillion gallons at any one time in our atmosphere. The hydrologic cycle ensures that billions of gallons of water are evaporating into or raining out of the atmosphere every day. This creates a never 
ending continuous supply of fresh water that is available and accessible almost everywhere in the world. Atmospheric water generator produces water similar to the way rain is made and is an environmentally friendly water dispensing system (purifying).

Many atmospheric water generators operate in a manner very similar to that of a dehumidifier: air is passed over a cooled coil, causing water to condense. The rate of water production depends on the ambient temperature, humidity, the volume of air passing over the coil, and the machine’s capacity to cool the coil. These systems reduce air temperature, which in turn reduces the air’s capacity to carry water vapor. This is the most common technology in use, but when powered by coal-based electricity it releases excess amount of carbon dioxide in the atmosphere and it demands more than four times as much water up the supply chain than it delivers to the user.

Many efforts are made to exact water from atmosphere, above shown process is vapor compression refrigeration cycle process (cooling condensation).In a cooling condensation type atmospheric water generator, a compressor circulates refrigerant through a condenser and then an evaporator coil which cools the air surrounding it. This lowers the air temperature to its dew point, causing water to condense. A controlled-speed fan pushes filtered air over the coil. The resulting water is then passed into a holding tank with purification and filtration system to help keep the water pure and reduce the risk posed by viruses and bacteria which may be collected from the ambient air on the evaporator coil by the condensing water. 
The rate at which water can be produced depends on relative humidity and atmosphere temperature and size of the compressor. Atmospheric water generators become more effective as relative humidity and air temperature increase. As a rule of thumb, cooling condensation atmospheric water generators do not work efficiently when the temperature falls below 18.3°C (65°F) or the relative humidity drops below 30%. This means they are relatively inefficient when located inside air conditioned offices. The cost-effectiveness of an AWG depends on the capacity of the machine, local humidity and temperature conditions and the cost to power the unit. Quench Innovations generator AwG-H1* 
Peak Power: 1.2 KW Humidity Range: 40-100% 24hr. Capacity: 14 Gallons Liters: 53 Liters Height: 19″ | 48 cm Width: 24″ | 61 cm Length: 33″ | 86 cm

Quench Innovations generators work where there is humidity in the air to be converted to water, drought areas included, like Agriculture, Hospitals, Industrial, Military, Residential and commercial, and Humanitarian. 
The use of atmospheric water generator (AWG) might solve our problem of scarcity of drinking water throughout the world. Fresh drinking water can be provided to the people who is suffering from diseases. Water pollution is also a major problem these days, people are facing lack of drinking fresh water. AWG technology – an environmental friendly technology, which makes water from air, protecting water resources. In future, this technology will be so essential, in this growing population and increasing pollution. In the context of Nepal, people of hill reasons are facing the problem of drinking fresh water, AWG helps to solve their problem. As this technology is new in Nepal, in future it will be essential and surely solves our problem of fresh water.