Freshwater is hard to obtain in many regions. These areas include even those with the highest of altitude with tons of suspended water in the air. The fact that there exists some moisture in the air doesn’t necessarily mean that it will fall as rain. However, both natural and technological advances can help with this situation. These help ensure that this water is drawn into the much-needed liquid form.
Some of the current technologies are in the market use electricity. This is a problem because of the costs of buying electricity and the pollution involved. Pollution is especially rampant when the energy used is from the combustion of fossil fuels. The maintenance of the devices that use electricity is also arguably more eminent as compared to the natural ways.
Since water exists in the air as moisture, solar energy is involved in the dynamics. As such, this text assumes that the solar energy supplied from the sun is part of the natural means of water acquisition from the air. Many ideas that have been created to obtain water from the atmosphere are based on the action of solar energy.
The benefits of using the sun’s energy to obtain this resource are countless. Some of the main advantages of the solar energy used for this purpose include the fact that it is renewable, provides clean energy and is available in most parts of the world. Furthermore, its availability is often concentrated in the places where the water is needed the most such as in arid regions. In places where the intensity of solar energy is not as much as the high quantity of water that is in the air, some element of infrared energy from the sun still exists. This can still be used to obtain fresh water without employing the use of electricity.
One of the major problems with water extraction from the atmosphere is that the volumes of humidity in the air might not always be sufficient to meet the efficiency needs of the devices. As a result, technological advances are constantly being made. These are designed to increase the capacity of water conversion into freshwater.
The other problem is the costs involved. It is not convenient to purchase devices that are greatly capital intensive and fail to provide the needed return on investment over several proceeding months. As such, designers are faced with the critical challenge to come up with devices that are not so expensive and take full advantage of however the water vapor in the air is. Water can exist in the air in several ways. Fog, for instance, is taken to be the existence of clouds such that they reach the ground surface.
The most ideal areas in which the fogs are to be found in good quantities are in coastal or hilly areas. However, a topography that exhibits both conditions is the most ideal- these are the raised terrains near the large water bodies. For the fog to be formed, nearby sources of recharge are often essential. For this purpose, the distance between the water collection device and the source is important. Short distances are ideal since very little evaporation occurs. However, this might not be practical. The installations might need to be placed more inland especially if obstacles have been encountered that block the winds. The wind is essential, since, without it, the device will not be able to reach out to the water-laden air.
How Water Exists in the Air
A region with adequate rainfall does not require moisture stripping technology and is more suited for roof harvesting systems. However, when the precipitation is inadequate, the air to water technology can be an invaluable asset.
The choice of technology to be used to draw water from thin air is dependent on the nature by which it exists at most times. The essential factors that need to be considered before embarking on a fog-collection venture include the availability of the water in the atmosphere in considerable quantity, sufficient wind speeds, and suitable topographic conditions.
Historical Instances of Air to Water Technology
Obtaining water from the atmosphere might seem like a recent innovation. Also, the complexity and the innovativeness involved might make it seem like a scientific breakthrough created by some genius. However, this is a technology that has always existed in nature. The powers of doing this were harnessed by communities in the past. These ancient communities probably drew inspiration from some natural phenomena. Examples of this historical phenomenon are given below:
Early Man and Survivalists
Since the beginning of time, man has been a survivalist as he tried to wade through life. Since modern technologies were not available during the early times, Man had to be innovative enough to get water. Water, being an essential element that supports life, the early man possibly had to lick the dew of some vegetation bearing dew early in the morning.
While this seems a primitive solution to water harvesting, it might be the only solution when is faced with the decision that determines0 life and death. As a result, many survivalists have relied on this method, which has continued to be practiced even in modern times. Another method that is popular among many survivalists globally is the practice of drinking the pools of water collected in plant leaves and stems.
Deserts and Other Locations
A variety of ancient devices that collect the water suspended in the air have been discovered in various world locations. These include the Ukrainian and Lanzarote stones which were designed to specifically serve this purpose.
Dew Ponds
Just as the name suggests, dew ponds have long been believed to be some natural collection systems of water in the form of dew. The success of these ponds has led to numerous scientific investigations to determine the main possible source of the replenishment of these systems. While one scientific community believes that the water results from the air, others are certain schools of thought that the moisture from the soil plays a major role.
The fact remains that these ponds, instead of being constructed in the natural low-lying areas, the designers only chose hilltops. As a result, the possibility of having water recharges from the spring is highly minimized. Furthermore, the bottom was made of materials that provided and insulation from the bottom, hence highly minimizing the chances of water infiltration.
Clay was majorly used among other items such as chalks and soot. An effort was done so that the layer would neither allow soul creatures such as earthworms to cause breakages, and also preventing from cracking when the sun got too hot.
The Incas
Incas are some of the renowned pioneers of water engineering. This community perfected not just rainwater collection but also harvested springs and dew from the air. With such technology, the Incas ensured that water scarcity was kept minimized the entire year.
The Incas fog collection system consisted of some bucket-like structures that were carefully positioned under twigs. The moisture in the air would collect overnight or on days when air moisture quantity was at a high. Subsequently, the air moisture would collect and drip into the bucket systems.
Modern Scientific Studies
Several modern studies have been conducted on some institutions and organizations. These are meant to achieve some goals. Some tend to replicate the ancient technologies while others amplify the already existing collection systems.
Success in a collection system is important since it can lead to integration into modern water security systems. Furthermore, new theories and technologies are integrated into pilot systems to increase efficiencies.
An example of fog harvesting was in South Africa in the 1960s and yielded substantial water daily. The other occurred in Chile in 1987where a greater volume of water was attained and helped to supplement the water to the locals in the region.
Natural Instances of Air to Water Harvesting
To understand the best technologies to be used at a particular place, it is important to understand how the plants and animals in that particular area make use of the resource. One technology that is so efficient at a particular point might prove ineffective at a different location.
Plants
Plants naturally require water to aid their functioning. The water is not always available to them since some habitats do not provide them with the water that they need. This necessitates some of them to forage water from the atmosphere. Some of these plants include:
Redwood Trees
These are trees that have the capability of living off very limited precipitation. They have adapted to harvesting water from the moisture-rich air. These trees have evolved to having needle-like leaves which continually provide adequate surface area for the condensation of water. In a process that replicates drip irrigation, the water from these needs continually drops into their roots.
Animals and Insects
Scientific research has noted some of the ways through which even animals acquire water from the air. While not so many animals possess this ability, some have in-built systems that help them convert the moisture into water. Some of these animals/insects are highlighted below:
Desert Beetles
Some beetles have set up their homes in deserts especially the Namib desert has the unique ability to obtain water directly from the air. The beetles are naturally equipped with wings that allow water to condense on them much as it does on leaves. The wing surfaces contain regions of water repulsion and those of water attraction.
Technological Advances that Require Electricity
This article focuses on the ways of converting air moisture by natural means. However, if the natural means do not meet your needs, and the source of energy is cost-friendly, and the pollution effects are not an issue, then you might consider purchasing an electric-powered machine.
Fog Catchers
Fog Catchers are particularly famed technological equipment that has been tested and commercialized. Despite their robust nature, their effectiveness in catching ‘fog’ is true in several regions. Currently, the project is set running in one Moroccan village and sustains several households.
The device works by providing a large surface area to the tiny and microdroplets of water in the air. Essentially, its core action involves the collection of these droplets and merging them. After this process, the force of gravity forces them to flow down, through appropriate conduits. The conduits lead them to reservoirs and eventually find their way to their families.
The brainchild of these devices was forty years ago in South America. It has since been installed in several regions across the world. The air laden with moisture is often lighter than air and tends to move upwards. As a result, the nets are placed in locations that are of high altitudes.
Care is taken to ensure that the wind that brings this moisture blows through it from the face rather than from the side. This enhances the rate of uptake and conversion of the moisture.
The determination of the best localities for its installation relative to the flow of wind and the differences in the moisture content is, therefore, an important aspect. In areas s such as Egypt, where desert conditions exist and high moisture content from the sea is available, the project has been successful.
Cloud Fishers
CloudFishers are natural collectors of moisture in the air with similar functionality and generally have some likeness to the ‘Fog-catchers’. This similarity is especially in the operation and also the mode of installation. However, the major difference between the two devices is that they can operate more efficiently especially when subjected to winds of high velocity.
According to the designers of this technology, it can withstand wind speeds of nearly 120 kilometers an hour due to the inclusion of extra expanders. The flexibility of the water collectors also enables the devices to collect more water. A greater volume of the mesh and safety of the equipment is a major selling point of these devices.
Meta-Organic Framework-MOF
A Meta-Organic Framework – MOF is a recent device that was a brainchild of scholars from the University of California. The product is an efficient technology that makes no use of electricity. It only harnesses solar power to function.
The mode of operation of this device is that it actively collects moisture from the surrounding at nighttime. At such a time, the temperatures are low and the water vapor has condensed into molecules that are easier to absorb through such means. MOF has a great density and may not only be used to collect the water. It can also be actively employed in industrial applications.
The device is noted for its property to absorb water as the result of Zirconium, an element that is part of the framework. The absorption and storage will occur simultaneously at nighttime and the solar energy will then provide the necessary energy needed to draw it out during the daytime. This device is especially effective in regions with quite low water in the atmosphere. As such, the production for small-scale usage can potentially be a game-changer to many households.
The question of whether this stored water can get lost easily especially during warm nights arises. However, the MOFs only release the stored water when subjected to a temperature of about 45 degrees. Such temperatures exceed the normal environmental conditions and might only be attained in enclosed situations such as in a greenhouse. In operation, the device, after having been placed in the night, and laden with water is enclosed so that heat from the sun heats it. The moisture then condenses to release freshwater potable water.
Mode of Operation of Fog Harvesters
Frame
Most collectors have three main parts in their design including the Overall frame, netting, and collection systems. The frame acts as the superstructure to the system and supports its major elements. The frame needs to be rigid enough to withstand the gravitational pulls, resist forces of wind and also be long-lasting.
A variety of materials can be used for this purpose including timber and metal such as stainless steel. Since the equipment is kept outside and is susceptible to rust, stainless steel is often used. For wood, bamboo is most desirable in certain regions due to its natural sturdiness as well as ease of availability.
The superstructure comes in several shapes such as rectangular, square, and cylindrical. However, care must be taken so that the chosen geometrics does not conflict with the local environment in which it is to be installed. Furthermore, the endpoints of these frames should be solidly embedded into the ground.
For more efficiency, it is common practice to include a secondary mesh besides the first one. This leads to vibrations when wind passes through and encourages the water droplets to flow downwards toward the collection chambers.
The Mesh
The central mesh area is probably the most important section of the whole system. The efficiency of the collection will be determined by the quality and material used to make the netting. The mesh is constituted of filaments that are intertwined together and leave small openings between. A modern addition to the design is to add a chemical substance to enhance the water condensation process.
Hydro-phallic and phobic properties are induced through the use of the chemical. This ensures that the water is attracted to the atmosphere. Once the tiny droplets adhere to the surface of the mesh, the hydrophilic property decreases the force of adherence to the netting, hence, encouraging the small droplets to adhere to each other. In this process, larger droplets are developed more rapidly.
A greater quantity of water can be achieved if the perforations between the filaments have smaller widths and the entire surface area of the mesh area is increased. Furthermore, the filaments that make up the netting need to be reduced in size to create a large surface area of contact. For this reason, stainless steel makes for the most appropriate material in the design of netting material.
Collection System
A final element of the harvesters is the collection system. This is often designed to maximize the collection of the condensed water by directing it into the collection chamber. The collector is often shaped like a half-sphere with the flat side open and facing upwards. They are also channeled towards the appropriate storage material to satisfy a variety of needs.
Electric vs. Non-electric Harvestors
Limitations of harvesters operating on electricity
Besides the fact that that the devices that use electricity to convert the water vapor promote pollution through the emissions from the burning of fossil fuels, their modes of operation are not suitable.
To extract the water, these devices make use of components known as desiccators. Desiccators refer to a matter that has a very high affinity to water. As such, they tend to take in the water vapor which can then be converted into the much-needed water. One of the most commonly used desiccators in these devices is the Zeolites.
Despite the notable affinity for the water in the air, these Zeolites tend to need adequate moisture content in the air for them to function properly. Furthermore, after the absorption of the water, one needs to extract it from the Zeolites. This is often made possible through heating the Zeolites in a process that is often made possible through the use of electrical energy.
Possible Limitations of Harvesters that don’t use electricity
The main limitation of using fog collectors is that their operations are dependent on the area’s climate conditions and the topography. Furthermore, they can’t give out larger volumes than they produce if an increase in need arises.
The changes in weather patterns determine the yield, hence consistency is a problem.
Toxicity can result in the collected water from a variety of sources including mold, insects, and other elements in the air. Hence, proper maintenance is necessary especially if the water is solely for human consumption.
Conclusion
Water is not always available to people in arid and semiarid areas. Almost one-third of the global population is in these areas. Without sustainable means of water acquisition, the harnessing of water from thin air will undoubtedly provide the much-needed resource to these people. The benefits of this are far-reaching especially if the natural water conversion devices are made more affordable and efficient in their operation.