Air Wells, Dew Ponds & Fog Fences Database

https://www.sciencedirect.com/science/article/abs/pii/S096014810300020X
Absorption/regeneration non-conventional system for water extraction from atmospheric air
Ahmed Sultan

Abstract -- The present work suggests a non-conventional method of water production from atmospheric air, on a 24-h basis using a compact system. The operation of the system is described and its efficiency is defined. The system performs under forced convection absorption and regeneration through a packed tower. The packed tower consists of two identical columns, each of them is packed with an identical bed. Each bed consists of vertical multi-layers of cloth material impregnated with calcium chloride solution of different concentrations. A numerical model, based on the experimental results, has been developed to predict the performance of the system under various operating conditions. The system efficiency is found to have peak values at certain cycle times, desiccant final concentration, regeneration temperature and absorption air stream velocity. It is also found that the maximum efficiency increases with initial concentration and decreases with the increase of the regeneration air stream velocity and absorption temperature.

Introduction
Extraction of water from atmospheric air is considered one of the important methods of fresh water supply, because air, as a source of water, is renewable, clean and exists anywhere. Several investigators have studied this problem. These investigations can be classified into two main groups. The first group deals with the cooling of air, while the second group studies the absorption–regeneration of the moisture directly from the air.

The extraction of water from atmospheric air can be done by cooling air to a temperature below its dew point, where moisture is condensed. Many investigations [1], [2], [3], [4], [5] have studied this method. Wind energy was used [6], [7] to circulate atmospheric air through the system condenser in order to separate moisture from it. Another approach for water extraction from atmospheric air is by absorption of water from atmospheric air into solid or liquid desiccant with subsequent separation of water from the desiccant by heating and condensation of vapor [8], [9].

Regeneration of an absorbent using solar energy was investigated [10], [11]. A comparative study for economical evaluation of the two methods mentioned above shows that the second system is more economic [2]. This comparison was carried out assuming the use of solar energy as the power supply of the two systems, with the use of Li Br absorption cycle for cooling system and applying Ca Cl2 as the working desiccant for the absorption–regeneration system.

An integral desiccant/collector system for production of fresh water from atmospheric air was studied [12]. The system involved absorption of water vapor from ambient air during the night and simultaneous desiccant regeneration and vapor condensation during the day. Description and analysis of the theoretical cycle for absorption of water from air with subsequent regeneration, by heating, was presented in [13]. Theoretical analysis showed that, strong and weak solution concentration limits play a decisive role in the value of cycle efficiency.

The present study was conducted as a part of a full scale project for water extraction from atmospheric air, whose purpose has been to design, build and test a complete system using cloth material impregnated with liquid desiccant. In this work, a non-conventional system applicable for periodically absorption and regeneration processes to extract water from atmospheric air is proposed. A definition of system efficiency based on the heat and mass balance calculations is presented. This work also studies the influence of air initial temperature, initial desiccant concentration and time period on the system efficiency. A suggested lay out of the water extraction plant is discussed and experimental data are used to show the effect of different parameters on the cycle efficiency.

Results and discussion
The system suggested in this work consists of periodically absorbing regenerating columns. Each column consists of an identical bed made of vertical multi-layers of cloth material impregnated with calcium chloride solution of different initial concentrations. The main aim of this work is to study the effect of the air inlet temperature and air mean velocity through both absorption and regeneration columns, on system efficiency. Also the effect of initial and final concentrations and cycle time

Conclusions
Analysis of the operation of the absorption/regeneration system for water extraction from atmospheric air, in the forced convection mode, has been developed. The system efficiency is defined in terms of the system design parameters. Also the effects of air temperature, air stream velocity and initial and final concentrations through the absorption and regeneration columns on the system efficiency have been well defined...

https://www.sciencedirect.com/science/article/abs/pii/S0960148106000462
Water production from air using multi-shelves solar glass pyramid system
A.E. Kabeel

Abstract -- The capability of the glass pyramid shape with a multi-shelf solar system to extract water from humid air is explored. Two pyramids were used with different types of beds on the shelves. The beds are saturated with 30% concentrated Calcium Chloride solution. The pyramid sides were opened at night to allow the bed saturated with moist air and closed during the day to extract the moisture from the bed by solar radiation. The bed in the first pyramid was made of saw wood while it is made of only cloth in the second pyramid with the same dimensions. The system was experimentally investigated at different climatic conditions to study the effect of pyramid shape on the absorption and regeneration processes. Preliminary results have shown that the cloths bed absorbs more solution (9 kg) as compared to the saw wood bed (8 kg). Adopting this approach produces 2.5 L/day m2. The use of the pyramid shape with four glass surfaces and multi-shelves enhances the produced water by 90–95% compared with solar desiccant/collector system with horizontal and corrugated beds. Results also show that the clothes bed has higher productivity than that of saw wood bed by about 5%. This is due mainly to the greater carrying solution at the onset of the experimental work. The obtained results may help in designing more efficient system.,,

Conclusions
An integrated desiccant solar pyramid collector system for producing water from ambient air has been designed, constructed and experimentally tested. Calcium chloride is applied as the working desiccant in this investigation. The system operation involves night absorption of water from ambient air by opening the four sides of the pyramid. During the daytime, the four sides are closed and then the desiccant regeneration as well as water vapor condensation occurs...

https://www.sciencedirect.com/science/article/abs/pii/S1359431114008199
Applied Thermal Engineering, Volume 75, 22 January 2015, Pages 513-531
A review on the use of calcium chloride in applied thermal engineering
Kokouvi Edem, et al.

Abstract -- The combination of its hygroscopy, heat of hydration, the low to medium melting points of its hydrates and its low material costs makes calcium chloride and the respective hydrates an attractive substance for various thermal processes. For refrigeration applications, the ammonia sorption is of high significance. The use of calcium chloride in pure or modified form is reviewed from the application point of view. A short analysis of the general physical and chemical properties highlights the advantageous properties. An overview is given about its use in the following applications: phase change material, desiccant, heat pumps and refrigeration and thermal energy storage. The advantages and challenges are discussed as well as approaches for technical improvement.

This paper reviews the use of calcium chloride in different forms, pure or in a composite material, in thermal applications. An emphasis is put on practical and experimental applications in order to point out interesting aspects of the material processing, properties, proven uses and challenges that remain. The interest for calcium chloride lies in the following non-exhaustive features and advantages, depending on the application:

Easy availability [13] because large quantities are produced as by-product of industrial processes [14], [15].
Subsequently, calcium chloride is one of the cheapest [13], [16], [9] (0.3–0.4 USD kg−1 [16], [17], [18], [19], [20], 2 USD kg−1 [15]), even the cheapest commercially available salt hydrate, depending on the application. This aspect makes it very attractive for many applications in particular those which need large quantities such as thermal storage applications.
A highly hygroscopic desiccating and sorption capacity [21], [22], in solid or liquid state. This property is widely used in industry, laboratories, commercial and domestic buildings: it has been shown that anhydrous CaCl2 could adsorb up to 90% of its own weight in moisture (water vapour) at ambient temperature and pressure [23]. The adsorption quantity is even higher than 100 wt% (weight percent) with ammonia [24] because 1 mol of calcium chloride can adsorb 8 mol of ammonia [25].
A relatively higher thermal conductivity, whether in solid or liquid state, compared to other materials of the same kind [26], [27].
A better thermal [1], [16] and chemical stability [15] than other salt hydrates
A less corrosiveness than other salt hydrates [16], [28]
A high latent heat of fusion (hexahydrate) [15]
A small volume change during phase transition [15]
Non-toxicity [29]
In sorption processes, it can be paired with different refrigerants (water, ammonia, methylamine, methanol, ethanol: see Fig. 1) [30], allowing various applications at various operation conditions
Low or moderate temperature operating range [31]
However, this material exhibits some undesirable behaviour:
Possible liquefaction of the material after absorbing a certain amount of water [24]
Excessive swelling/expansion (2:1 [24]) and agglomeration in particular when used in absorption cycle with ammonia [32], [22], [24]: this degrades heat and mass transfer and results in the decrease of reaction rate after several cycles [33]
Depending on the use, disintegration/decomposition/deterioration after several operating cycles [25], [32], [34] when no special measure is taken [13]
Corrosive to certain metals in the presence of excess oxygen because of chloride-induced corrosion [35]. However, this corrosion problem is practically no real threat any more when the process is run under near vacuum conditions (limited air or oxygen in an adsorber [35]), which is usually the case.
Because of its multiple uses, the properties of calcium chloride have been extensively studied; they are provided in Table 1 for the calcium chloride hydrates. As for the aqueous solution of calcium chloride and other working pairs involving calcium chloride, Table 2 and Table 3 summarise some references that give their properties. Solubility data in water, methanol and ethanol [36] are given in Fig. 2.
Various tetrahydrates are reported, among which the α and β tetrahydrates are deemed to be stable [37], [38], [39].
The pH of melted CaCl2·6H2O has been reported to be 6 [28]. Corrosion data of the calcium chloride aqueous solution for some materials can be found in Table 4. Corrosion is increased with the mass fraction and the temperature. For example, the stainless steel 304 is resistant to calcium chloride aqueous solution when the mass fraction is at about 10 wt% and when the mass fraction is about 28 wt%, the corrosion is about 0.003 mm year−1 at 79 °C [40]. Further corrosion data on CaCl2·6H2O have been reported by Cabeza et al. [28]. The study indicates that CaCl2·6H2O can be used in a metal container of brass and copper for long term service. Steel and aluminium are less resistant to CaCl2·6H2O and are recommended only for short term applications, but with caution. As for stainless steel, no corrosion was observed by the authors but they suspected that pitting could appear.

https://www.sciencedirect.com/science/article/abs/pii/S0735193322000094
Water production enhancement from the air moisture using nanofluids-experimental investigation and exergo-enviroeconomic analysis
Masoud Kave,et al.
A device consisting of refrigeration and moisture distillation cycles has been designed. Pure water from the air moisture has been provided.
The system performance has been enhanced using nanofluids. An exergo-enviroeconomic analysis has been performed.

Abstract -- Nowadays, the expansion of communities and population growth has further highlighted the need for clean water. To solve this problem, various methods have been proposed. Water extraction from the air moisture is of these methods which involve cooling the air to its dew point in which the moisture transforms from the gas to the liquid phase. In the present study, a device consisting of a refrigeration cycle and a moisture distillation cycle was designed to provide pure water from the air moisture. Additionally, it was tried to enhance the system performance by dispersing nanoparticles such as Cu and Al2O3 into the working fluid of the heat exchanger. In this study, the influence of various parameters (including inlet air velocity and ambient humidity) on the performance of the system was investigated. Finally, an exergo-enviroeconomic analysis was performed in terms of water production and cost. Based on the results, with increasing the air humidity from 40% to 60%, the amount of water production of the system raised from 0.5 to 1.8 cc/min. It was also observed that dispersion of Cu and Al2O3 nanoparticles enhanced the water production by around 43% and 29%, respectively. Moreover, an increment in inlet air velocity reduced the water production; while increasing the air humidity had a constructive effect on the system performance. The economic analysis indicated that the water production during a year increased by about 42% upon using Cu nanofluid as the working fluid of the distillation cycle which declined the water production cost by 32%.

Conclusion
The performance of a coupled system consisting of a refrigerant cycle and a water distillation cycle was comprehensively investigated. In the present research, various parameters including mass flow rate of the produced freshwater, COP, and total efficiency of the system were studied under various working conditions. To study the effect of ambient humidity, the system was examined at ambient humidity of 40% and 60%. Moreover, the effect of inlet air velocity on the copper spiral pipe was

https://www.sciencedirect.com/science/article/abs/pii/S0960148100001129
Application of a solar desiccant/collector system for water recovery from atmospheric air
H.E Gad, A.M Hamed, I.I El-Sharkawy

Abstract -- An integrated desiccant/solar collector system for production of fresh water from atmospheric air is described. The solar driven system provided about 1.5 l of fresh water per square meter per day. The system involves the absorption of water vapor from ambient air during the night and simultaneous desiccant regeneration and water vapor condensation during the day. To enhance the mass transfer surface, a thick corrugated layer of cloth was used as a bed to carry the liquid absorbent. In the nocturnal phase of operation, air is allowed to penetrate the desiccant bed. The airflow is driven by fans supported on one side of the desiccant/solar collector unit. In this study, the effects of different parameters on the absorption and regeneration processes are discussed, and operational conditions for the proposed equipment evaluated. Radiation intensity, ambient temperature, bed temperature and temperature of the glass surface were recorded. Also, the productivity of the system during the day and under the given operation conditions was plotted. A mathematical model was prepared and its output compared with the analyzed experimental data...

Conclusions
The performance of a desiccant/collector system with a thick corrugated layer of blackened cloth to absorb water vapor at night from atmospheric air with subsequent regeneration during the day, using solar energy, was assessed. Actual recorded results show that the solar operated system can provide about 1.5 l of fresh water per square meter per day. System operation and associated problems were discussed. System efficiency was defined and values of more than 17% were recorded...

https://www.sciencedirect.com/science/article/abs/pii/S1359431120311807
Solar powered atmospheric water harvesting with enhanced LiCl /MgSO4/ACF composite
M. Ejeian, A. Entezari, R.Z. Wang
Chemical adsorbents such as salt composites are still the first option in Adsorptive Atmospheric Water Harvesting. LiCl/MgSO4/ACF composite is a suitable choice in AAWH, especially in areas with moderate relative humidity. In an AAWH system, the desorption rate is limited to the heat transfer rate of the condenser. The higher the relative humidity, the lower the energy intensity of the atmospheric water harvesting. Our prototype produced 0.92 g/g water in an arid climate powered by solar energy.

Abstract -- Air humidity, as a source of water, is more or less available everywhere. The sorption capacity of water is a significant factor for the efficiency of atmospheric water harvesting (AWH) systems, which are based on the adsorption phenomenon. Lithium chloride has a high water-uptake rate, but has a very low delinquency relative humidity (DRH). Therefore, a host is required to make a stable composite. Composite of activated carbon fiber (ACF) and lithium chloride can keep the adsorbent immobile even after the occurrence of deliquescence, which also causes the three-phase sorption. However, the amount of salt inside the composite is limited by the prevention of leakage. In this paper, a binary salt composite is produced by a new method in order to enhance the water sorption capacity in terms of volume, and mass and the prevention the leakage. The effect of adding MgSO4 to the composite has been experimentally investigated for at different levels of relative humidity. The results showed that sorption capacity per unit volume and mass can be improved by the two-stage addition of MgSO4 without leaking in the adsorbent, reaching 0.78 g water/cm3 and 2.29 gwater/gadsorbent. The prototype made by the selected composite showed that AWH energy intensity was lower at higher relative humidity. The device was tested successfully in an arid climate and produced 0.92 gwater/gadsorbent when maximum RH reached 35% during the adsorption process.

Conclusions
In this study, LiCl/MgSO4/ACF composites were constructed by using two different methods and compared with the LiCl/ACF composite. The results showed that the two-step method had a positive effect on net uptake water and sorption density, because it creates a separate network structure for each salt. The presence of MgSO4 in the composite, on the one hand, leads to the expansion of the three-phase sorption region, which improves the mass transfer in the system. On the other hand, it increases...

https://www.sciencedirect.com/science/article/abs/pii/S0011916415002544
Experimental investigation of solar powered water production from atmospheric air by using composite desiccant material “CaCl2/saw wood”
Manoj Kumar, Avadhesh Yadav
SGDBS (solar glass desiccant box type system) has been used as an experimental setup. Six samples of composite desiccant material CaCl2/saw wood have been prepared. 180 ml/kg/day of water can be produced by using the composite desiccant material. For 500 ml/m2/day, 2.8 kg of the composite desiccant material are required

Abstract -- New composite material for storage and production of water from atmospheric air has been investigated experimentally. Experiments have been performed in the Indian climatic condition at NIT Kurukshetra, India [29° 58′ (latitude) North and 76° 53′ (longitude) East] in the month of October. Three numbers of newly designed solar glass desiccant box type system (SGDBS) having a capture area 0.36 m2 each, have been used. The design parameters for the water production are height of glass from desiccant bed at 0.22 m, inclination in angle at 30°, effective thickness of glass at 3 mm and number of glazing as single. It is found that water production rate depends upon the concentration of CaCl2 in the saw wood. Maximum quantity of water production by the composite material having 60% concentration is 180 ml/kg/day.

https://www.researchgate.net/publication/245189660_Absorptionregeneration_non-conventional_system_for_water_extraction_from_atmospheric
July 2004Renewable Energy 29(9):1515-1535
Absorption/regeneration non-conventional system for water extraction from atmospheric
Ahmed Abdel Rrazik Sultan

Abstract -- The present work suggests a non-conventional method of water production from atmospheric air, on a 24-h basis using a compact system. The operation of the system is described and its efficiency is defined. The system performs under forced convection absorption and regeneration through a packed tower. The packed tower consists of two identical columns, each of them is packed with an identical bed. Each bed consists of vertical multi-layers of cloth material impregnated with calcium chloride solution of different concentrations. A numerical model, based on the experimental results, has been developed to predict the performance of the system under various operating conditions. The system efficiency is found to have peak values at certain cycle times, desiccant final concentration, regeneration temperature and absorption air stream velocity. It is also found that the maximum efficiency increases with initial concentration and decreases with the increase of the regeneration air stream velocity and absorption temperature.

https://www.sciencedirect.com/science/article/abs/pii/S0038092X18303451
Water generation from atmospheric air by using composite desiccant material through fixed focus concentrating solar thermal power
Shobhit Srivastava, Avadhesh Yadav
Scheffler reflector is used for fast water production. Composite desiccant material LiCl/sand, CaCl2/sand & LiBr/sand have been used. Absorption rate and regeneration rate are carried out for water production. 115 ml/day of water can be produced from CaCl2/sand.

Abstract -- In this manuscript, experimental investigations have been performed in order to generate water from atmospheric air by using different composite materials under atmospheric condition of NIT, Kurukshetra, Haryana, India [29°58′ (latitude) North and 76°53′ (longitude) East]. In this analysis, three composite materials named LiCl/sand(CM-1), CaCl2/sand(CM-2) and LiBr/sand (CM-3) have been used as salt with 37% concentration and sand as a host material. The absorption and regeneration processes have been performed to generate water from atmospheric air. The absorption process has been carried out at night in the open atmosphere whereas regeneration process took place during the day time by using newly designed 1.54 m2 Scheffler reflector. The maximum amount of water generated from CM-1, CM-2 and CM-3 are 90 ml/day, 115 ml/day and 73 ml/day in 330 min, 270 min and 270 min respectively and the annual cost of water generation are $0.71, $0.53 and $0.86 respectively.

US6490874 -- Recuperative Environmental Conditioning Unit

US8752330 -- Plant Aid, Water Collection Sheet and Method

Marit JAGTOYEN
Auto Exhaust Water Recovery System

http://lexcarb.com
Development of On-Board Water Recovery Unit for the Future Combat System (FCS), HMMWV and the Tactical Quiet Generator
Executive Summary
The primary goal is to develop a fully integrated and automated prototype system for the collection, purification and storage of potable water from the exhaust gases of military land vehicles. A heat exchanger & refrigeration system is used to recover water generated during the combustion process. The system is designed to operate under desert conditions. A mesoscale heat exchanger is under development at MesoSystems, Inc. This unit would be smaller than conventional heat exchangers and could eventually fit in the wheel arch of the HMMWV. The water cleanup is performed using a purification train under development consisting of an ultra-high efficiency glass fiber filter, activated carbon and carbon fiber, zeolites and ion exchange resins. The water purification canister design is challenging since the water contains a mixture of organic and inorganic acidic compounds. Currently, the water meets drinking water standards with a TOC of < 2 ppm and in most cases is less than 0.5 ppm, and a metal's content below EPA regulated limits. Identification and removal of remaining TOC is the focus of current research. For comparison most municipal water supplies have a TOC of 2-3 ppm.

The successful development of a system that produces potable water from vehicle exhaust and is small enough to be of military utility will augment a unit's water supply and reduce its dependence on the supply infrastructure. This will lead to a more mobile, deployable, and flexible force. The technology will also provide water to small units in water scarce environments. The system will provide safe, lifesaving, drinking water in disaster relief and emergency applications. It could also provide recreational vehicles in water scarce environments with a critical survival tool...

But don't ask Jagtoyen, who can often be seen driving a red Hum-Vee around town, to chug a bottle of her diesel water just yet. There are still traces of two unidentified compounds in the otherwise pure water. They're probably harmless, she said, but so far she's only sipping.
US6581375 -- Apparatus and Method for the Recovery and Purification of Water from the Exhaust Gases of Internal Combustion Engines [ PDF ]

KOHAVI: Air Well

Marc Parent : Air Well

http://www.reuters.com/news/video?videoId=113820&videoChannel=6
Inventor Makes Water out of Air
Oct 28 - A French inventor has come up with a windmill that turns thin air into water and says his creation could offer hope to millions of people around the world who do not have enough water.

FR2833044 -- Machine for Producing Water from Wind Energy   [ PDF ]

QINETIQ: Dew Collector

RETEZAR: Fontus Air Well

RICHARDS: AquaMagic Water Generator

SHER: Air Well

THEILOW: Air Well

VITTORI: WarkaWater Airwell

WHISSON: Air Well

YAGHI: MOF Airwell

Fog Collectors

HENG / LUO: Fog Collector

McKINLEY: Fog Fence

OLMO / GIL: Fog Collector

ARTICLES

Chem. Engg Transactions
New Architectural Forms to Enhance Dew Collection
Daniel Beysens, et al.
[ PDF ]

Abstract -- Dew water is water vapour that passively condenses from air. Once properly collected, it can provide a useful supplementary water resource for plants and humans. Its production can be significantly improved by using specific materials and particular geometry. In this context, new shapes for dew collectors are presented and their water yields are compared with those of a 1 m 2 , 30°, inclined planar condenser used as a standard. The experiments were carried out in Pessac (SW France), situated about 45 km from the Atlantic Ocean, during summer and fall 2009. In addition to conical shapes, which have 30 % larger yields than the planar reference condenser and whose functioning was simulated numerically, two new families of forms are considered: egg-box and origami types. The egg-box shape yields 9 % more water as compared to the reference planar condenser, a result nearly independent of the dew yield. In contrast, the origami shape gives yields 150 % larger than the reference planar condenser for events with high dew volumes and can show 400 % greater yields for low dew volumes. These results are analysed and discussed in terms of (i) radiative effects correlated with the angular variation of sky emissivity, (ii) heat losses by free and forced (wind) air convection and (iii) gravity water flow. General rules to increase dew collection are introduced.

Production d'eau dans un ancien sarcophage à Arles - sur - Tech (France)
D. Beysens, et al.
[ PDF ]

Abstact -- Depuis le 16ème siècle, au moins, un sarcophage scellé, situé dans la cour de l'abbaye d'Arles-sur-Tech (France), est réputé produire des centaines de litres d'eau par an. Beaucoup d'hypothèses ont été avancées pour expliquer ce mystère. Après avoir recueilli pendant environ trois ans des données, nous concluons que cette quantité d'environ 200 litres d'eau par an, est le bilan final d'une entrée d'eau de pluie, de rosée condensée et d'évaporation. Des défauts dans la jonction du couvercle et du corps du sarcophage permettent un échange avec l'atmosphère...

FOG AND DEW COLLECTION PROJECTS IN CROATIA
M. Mileta, et al.
[ PDF ]

Abstract -- The present paper discusses the fog and dew water collection in Croatia. Zavižan, the highest meteorological station in Croatia( 1594m) is chosen for collecting of fog water with a standard fog collector (SFC). The highest daily collection rate was 27.8 L / m². The highest daily collection rate in days without rain was 19.1 l/m². Dew is also a noticeable source of water, especially during the drier summer season. Dew condensers in Croatia have been installed on the Adriatic coast (Zadar) and islands Vis and Biševo. We report and discuss the data collected since 2003. In the small Biševo island, a special roof has been designed to improve the formation and collection of dew on a house. Data from April 2005 will be presented.

https://www.science.org/doi/10.1126/sciadv.aao5323
Electrostatically driven fog collection using space charge injection
A. Damak, et al.
[ PDF ]

Abstract -- Fog collection can be a sustainable solution to water scarcity in many regions around the world. Most proposed collectors are meshes that rely on inertial collision for droplet capture and are inherently limited by aerodynamics. We propose a new approach in which we introduce electrical forces that can overcome aerodynamic drag forces. Using an ion emitter, we introduce a space charge into the fog to impart a net charge to the incoming fog droplets and direct them toward a collector using an imposed electric field. We experimentally measure the collection efficiency on single wires, two-wire systems, and meshes and propose a physical model to quantify it. We identify the regimes of optimal collection and provide insights into designing effective fog harvesting systems.

https://www.science.org/doi/epdf/10.1126/sciadv.aao5323
Hydrol. Earth Syst. Sci., 19, 601–613, 2015
Estimates of global dew collection potential on artificial surfaces
H. Vuollekoski, et al.
[ PDF ]

Abstract -- The global potential for collecting usable water from dew on an artificial collector sheet was investigated by utilizing 34 years of meteorological reanalysis data as input to a dew formation model. Continental dew formation was found to be frequent and common, but daily yields were mostly below 0.1 mm. Nevertheless, some water-stressed areas such as parts of the coastal regions of northern Africa and the Arabian Peninsula show potential for large-scale dew harvesting, as the yearly yield may reach up to 100 L m^2 for a commonly used polyethylene foil. Statistically significant trends were found in the data, indicating overall changes in dew yields of between ±10 % over the investigated time period.

Natural Resources, 2011, 2, 8-17
Application of Solar Energy for Recovery of Water from Atmospheric Air in Climatic Zones of Saudi Arabia
Ahmed M. Hamed
[ PDF ]

Abstract -- In the present work, an investigation on the application of solar energy to heat a sandy bed impregnated with calcium chloride for recovery of water from atmospheric air is presented. The study also aimed at evaluating the effects of different parameters on the productivity of the system during regeneration. These parameters include system design characteristics and the climatic conditions. An experimental unit has been designed and installed for this purpose in climatic conditions of Taif area, Saudi Arabia. The experimental unit which has a surface area of 0.5 m 2, comprises a solar/desiccant collector unit containing sandy bed impregnated with calcium chloride. The sandy layer impregnated with desiccant is subjected to ambient atmosphere to absorb water vapor in the night. During the sunshine period, the layer is covered with glass layer where desiccant is regenerated and water vapor is condensed on the glass surface. Ambient temperature, bed temperature and temperature of glass surface are recorded. Also, the productivity of the system has been evaluated. Desiccant concentration at start of regeneration is selected on the basis of the climatic data of Al-Hada region, which is located at Taif area, Saudi Arabia. Experimental measurements show that about 1.0 liter per m 2 of pure water can be regenerated from the desiccant bed at the climatic conditions of Taif. Liquid desiccant with initial concentration of 30% can be regenerated to a final concentration of about 44%. Desiccant concentration at start of regeneration is selected on the basis of the climatic data of Al-Hada region. The climate of Taif city is dry compared with that for Al-Hada region. This method for extracting water from atmospheric air is more suitable for Al-Hada region especially in the fall and winter.

Secheresse, 11 (4), Dec. 2000
THE CASE FOR ALTERNATIVE FRESH WATER SOURCES
D. Beysens, et al.
[ PDF ]

Abstract -- This paper describes alternatives to the traditional methods of obtaining fresh water. It covers the recovery of atmospheric humidity, fog and water vapour, in addition to seawater desalination, which is analysed briefly. It examines fog recovery while focusing more closely on how the condensation of atmospheric water vapour (dew) has been realised in the past and why higher yields can now be envisaged. Adsorption processes using regenerative desiccants are also considered.

J. Hydrology 405: 171-181 ( 2011 )
A very large dew and rain ridge collector in the Kutch area (Gujarat, India)
G. Sharan, et al.
[ PDF ]

Abstract -- The world’s largest dew and rain collecting system, comprised of ridge-and-trough modules, was constructed in March 2006 at Panandhro in the semi-arid area of Kutch (NW India). The main goals were (i) to collect dew on a scale that could be beneficial to the local population (ii) to determine the efficiency of this new module shape, (iii) to determine whether results obtained from small measurement condensers can be projected to large condensers, (iv) to apply a computational fluid dynamic simulation to improve the condenser set-up. Preliminary studies performed with four standard plane condensers of 1 m2 surface area, inclined 30° from horizontal, identified Panandhro as a promising site. The cumulated dew water during 192 days was 12.6 mm with a maximum of 0.556 mm/night. A large dew condenser (850 m 2 net total surface) was designed with 10 ridge-and-trough modules. The ridges are trapezoidal, 33 m long, 0.5 m wide at the top, 2.2 m wide at the base and sloping 30° from horizontal. The depth of the troughs between the ridges is 0.5 m. A 2.5 cm thick polystyrene foam rests on the surface as insulation with a radiative foil on top (similar to that developed by OPUR, see www.opur.fr). Numerical simulations using the computational fluid dynamic software PHOENICS were performed. The most profitable orientation was with the condenser oriented back to the wind direction, a configuration that lowers the wind velocity near the foil due to the combination of free convection and wind
recirculation flows. A comparison of water yields over one year of measurements between four 1 m 2 plane condensers and a 850 m 2 ridge condenser showed a 42% lower yield on the large condenser. The difference is attributed mainly to folds in the plastic foil allowing water to fill the central ridge, thus decreasing radiative cooling. The output for 2007 was 6545 L, corresponding to 7.7 mm/day on average. The largest event was 251.4 L/night (0.3 mm). Such a condenser can also collect rain (and, to a lesser extent, fog). Chemical and biological analyses showed that dew water, once filtered and bottled, could be used for drinking after a light treatment to increase the pH. The price of this water could be lowered to reach 30% (dew only) or even 3% (dew plus rain) of the market prize.

CIBSE Technical Symposium, DeMontfort University, Leicestern UK – 6th and 7th September 201
EXPERIMENTAL INVESTIGATIONS ON WATER RECOVERY FROM THE ATMOSPHERE IN ARID HUMID REGIONS
Esam Elsarrag, et al.
[ PDF ]

Abstract -- The Gulf region is one of the most arid regions in the world. The lack of water is considered as the most important problem. Annual rainfall is slight and erratic, with an annual average of 81 millimetres in Doha. As a result, renewable ground water resources are extremely limited and, in addition, there are problems with groundwater salinity. The atmosphere, endless source of water, contains a large quantity of water in the form of vapour in varying amounts especially in Gulf coastal region. In this paper two methods of collecting water from the atmosphere are presented. First by collecting condensate water, which is usually discarded, from existing air conditioning systems. Experimental measurements of water recovered from the atmosphere by existing air conditioning systems have been carried out. The average rate of condensed water collected during the experiments is found to be about 7.2l/day per kW cooling. The experiments demonstrate a cost efficient means of water recovery which can be implemented in air conditioned buildings. The second method is a novel tilted solar absorption/desorption system, modified from conventional solar still, which used to collect water from the atmosphere. Air is entered to the system at night where water is absorbed by the desiccant. In the daytime the desiccant is heated by solar energy to evaporate the absorbed water. Calcium chloride is used as the desiccant and a corrugated blackened surface is used to heat the desiccant in daytime. It is found that the factors have the greatest effect on the evaporation of water from the desiccant are the temperature difference between the desiccant and the glass and the desiccant flow rate. The higher evaporation rate from the solar tilted unit is found to be about 0.18l/min per m2 of solar collector area.

European Journal of Science and Technology, Special Issue 32, pp. 991-999, December 2021
A Literature Review on Extraction of Potable Water from Atmospheric Air Using Solar Stills: Recent Developments
Merdin Danışmaz, et al.
[ PDF ]

Abstract -- Drinking water and utility water are indispensable elements in meeting many vital needs, especially drinking, cooking and cleaning. Unconscious agricultural irrigation, pollution, and population growth cause water scarcity that humanity must cope with. As a result of global warming and climate change, especially the amount of potable water is decreasing, making it difficult to access clean water resources. The occupancy of drinking water sources decreases in high temperature seasons and some of them even disappear. This situation has made it necessary to search for alternative methods to obtain drinking water. One of these methods is to obtain potable water from atmospheric air containing high amounts of water. With the widespread use of this method, the scarcity of drinking water can be alleviated to a certain extent. In this study, the processes of condensing the water in the atmospheric air by using solar energy, which is a renewable energy source, and thus obtaining potable water are discussed. Efforts to increase the efficiency of obtaining potable water by using various absorbents and by various systemic solar still designs have yielded positive results. As a result of this literature review, the limits of the studies and their regional effectiveness were evaluated together. The effect of temperature, velocity, humidity of the atmospheric air and the amount of solar radiation on the process were evaluated. It has been concluded that certain desiccant materials with good water absorbers such as calcium chloride and silica gel can be used effectively in the processes of obtaining potable water from atmospheric air by developing correct designs. It has been demonstrated that high atmospheric air temperature, which is an important cause of water scarcity, can be converted from disadvantage to advantage by utilizing solar energy.

https://www.academia.edu
WEENTECH Proceedings in Energy, ICEEE 2016, 16th -18th August 2016
Potential for Extracting Water from atmospherically Jordanian Air
Ahmad Al-Sarayrah
[ PDF ]

Abstract -- This paper aims to provide solutions for water supply in regions suffering from shortage of fresh water, and contaminated water. It presents a method to extract pure water from atmospheric air. It depends on intensifying the water vapor from the air. The plant was designed to perform the optimum levels to produce high quality water with minimal electricity consumption. The harvesting water was inspected and analyzed based on ISO/IEC 17025 method to check the purity water. This study also investigates the potential of using a solar powered for atmospheric water generation (AWG) as a new option for fresh water production. A proposed solar AWG unit was assembled, analyzed and modeled using HOM ER software. The results demonstrated that the water produced by the water extraction plant is pure, safe, economical, and acceptable tasting. It can be used as drinking water after treated by filter and disinfected by Ultra Violet Light (UV) technique. The feasibility analysis showed that there is a potential to adopt solar powered of AWG as strategic and alternative option for a small area; which is suffering from shortage of drinking water.

https://www.mdpi.com/1996-1073/15/2/421
A Recent and Systematic Review on Water Extraction from the Atmosphere for Arid Zones
Suad H Danook
[ PDF ]

Abstract -- Water is essential for food security, industrial output, ecological sustainability, and a country’s socioeconomic progress. Water scarcity and environmental concerns have increased globally in recent years as a result of the ever-increasing population, rapid industrialization and urbanization, and poor water resource management. Even though there are sufficient water resources, their uneven circulation leads to shortages and the requirement for portable fresh water. More than two billion people live in water-stressed areas. Hence, the present study covers all of the research based on water extraction from atmospheric air, including theoretical and practical (different experimental methods) research. A comparison between different results is made. The calculated efficiency of the systems used to extract water from atmospheric air by simulating the governing equations is discussed. The effects of different limitations, which affect and enhance the collectors’ efficiency, are studied. This research article will be very useful to society and will support further research on the extraction of water in arid zones.

https://www.researchgate.net/publication/285533435_A_technical_review_on_the_extraction_of_water_from_atmospheric_air_in_arid_zones
Journal of Heat and Mass Transfer, Volume 4, Number 3, 2010, Pages 213-228.
A Technical Review on the Extraction of Water from Atmospheric Air in Arid Zones
Prof Ayman A Aly
[ PDF ]

Abstract -- Fresh water supply is one of the most limiting conditions for the populations of arid regions. The present paper covers the working principles of systems and processes for extracting water from atmospheric air. Moreover, a summary of the experimental and analytical studies which investigate system performance has been made. Some new designs that greatly expand the solar desiccant technique for absorption with subsequent regeneration are also introduced. The research activities in this sector are still increasing to solve the crucial points that make these systems not yet ready to compete with other systems as water distillation.

https://www.academia.edu/89958072/Solar_Powered_Atmospheric_Water_Generation_and_Purification_System?email_work_card=title
Development of Solar Powered Atmospheric Water Generation and Purification System
Jromed Cheng
[ PDF ]

...The device mainly consists o\f condensing block for condensing the moisture air and inlet fans for sucking air into system and solar powered battery and external supply for to drive the system. And last but not least the whole system is controlled by the Arduino Uno.

https://web.archive.org/web/20110614152852/http://www.iimahd.ernet.in/publications/data/2007-08-05Gsharan.pdf
Harvesting dew to supplement drinking water supply in arid coastal villages of Gujarat
Girja Sharan
[ PDF ]

Abstract -- Shortage of drinking water is chronic, sever and widespread in Kutch - a hot and very arid region. It is specially acute in coastal villages where surface sources dry up rapidly and groundwater is not potable. Many of these are listed as “no source” villages and are supplied water on tanker-trucks daily from long distances. The conventional efforts to conserve and augment water resources are all in place. But one potential resource - dew - had remained unnoticed. The possibility that it may also be a supplementary resource was first noticed in the summer of 2001 when it was observed that dew condensed frequently on a plastic- clad greenhouse in Kothara, a village 15 km from the coast. That led us first, to carry out systematic measurement, and then to develop practical ways to harvest dew for human use

Journal of Arid Environments
Comment on ‘‘The moisture from the air as water resource in arid region: Hopes, doubt and facts’’ by Kogan and Trahtman
D. Beysens, et al.
[ PDF ]

Abstract -- Kogan and Trahtman [2003. The moisture from the air as water resource in arid region: hopes, doubts and facts. Journal of Arid Environments 53, 231–240] analysed the functioning of a passive dew condenser built by F.I. Zibold in 1912 in Feodosia, and proposed a model to explain how thousands of litres of condensed water might be generated per day based on Zibold’s design. In a previous publication, some of the present co-authors explained why it was not possible to obtain high water yields with Zibold-style dew condensers and that Zibold was apparently unaware that the stone heaps in Feodosia were in fact ancient Scythian and Greek tombs. Kogan and Trahtman [2003] take issue with our findings, thus the reason for this comment.

https://www.mdpi.com/2673-7248/5/4/43
Textiles 2025, 5(4), 43
Alternative and Sustainable Technologies for Freshwater Generation: From Fog Harvesting to Novel Membrane-Based Systems
Musaddaq Azeem, et al.
[ PDF ]

Abstract -- Water scarcity is an escalating global challenge, driven by climate change and population growth. With only 2.5% of Earth’s freshwater readily accessible, there is an urgent need to explore sustainable alternatives. Textile-based fog collectors are advanced tools which have shown great potential and have gained remarkable attention across the world. This review critically evaluates emerging technologies for freshwater generation, including desalination (thermal and reverse osmosis (RO)), fog and dew harvesting, atmospheric water extraction, greywater reuse, and solar desalination systems, e.g., WaterSeer and Desolenator. Key performance metrics, e.g., water yield, energy input, and water collection efficiency, are summarized. For instance, textile-based fog harvesting devices can yield up to 103 mL/min/m2, and modern desalination systems offer 40–60% water recovery. This work provides a comparative framework to guide future implementation of water-scarcity solutions, particularly in arid and semi-arid regions.

https://advanced.onlinelibrary.wiley.com/doi/full/10.1002/adfm.202306162
Bio-Inspired Fog Harvesting Meshes: A Review
Brook S. Kennedy, Jonathan B. Boreyko

Abstract -- Freshwater scarcity has become a critical global challenge aﬀecting some of
the most vulnerable populations. In response, signiﬁcant eﬀort has focused on ways to increase access to this precious resource. Within the context of geographical, cultural, political, and technological factors governing freshwater availability, atmospheric water harvesting (AWH) has demonstrated tremendous promise to help address these shortages.
Speciﬁcally, mesh-based fog harvesters have received considerable attention for their passive qualities compared with their energy-dependent technological siblings (sorbents, condensation, etc.), yet their speciﬁc water yield (SY) has developed only modestly in recent decades. While the plant and animal kingdom provide diverse examples of passive fog collection, and science has developed a remarkable understanding of these processes, much of this knowledge has yet to be translated practically at scale. This is partially due to challenges in mass-producing complex (often micro-scale) structures observed in nature. Fortunately, manufacturing technology is catching up with scientiﬁc understanding, especially at the scale of mesh design. To this end, the review begins by surveying bioinspired research in fog harvesting. Afterward, this study identiﬁes milestones in developing bioinspired fog harvesting meshes, concluding in a discussion of future mesh research opportunities connecting bioinspiration and emerging advanced manufacture...

https://www.sciencedirect.com/science/article/abs/pii/S0140196305001096?via%3Dihub
A comparative study of two large radiative dew water condensers
M. Muselli, D. Beysens, I. Milimouk

Abstract -- In order to improve the yield of dew condensation from atmospheric vapor, two large (30 m2 in area) insulated plane radiative condensers, inclined at 30°, were installed in Ajaccio (Corsica island, France; latitude 41°55′N, longitude 8°48′E). Prototype P1 was elevated such that the underside was open and exposed. Prototype P2, however, was enclosed on all sides and closer to the ground. Both used a special radiative foil that enhances dew formation. The period of observation for P1 was July 22, 2000–November 11, 2001, and for P2 was December 10, 2001–December 10, 2003. All data were compared with respect to the same horizontal calibration plate of polymethylmethacrylate (Plexiglas) placed at 1 m above the ground on a sensitive recording balance. Water yield of both prototypes were compared and correlated against meteorological data (cloud cover, relative humidity, wind speed, condenser temperature and air temperature). Both prototypes exhibit improved performances when compared with the calibration plate: more dew days (+16% and +15% for P1 and P2, respectively); decrease of the humidity threshold (−3% and −4.4% for P1 and P2); increase of dew yields for wind speeds up to 3 m s−1. A model of the mass and thermal exchanges with the ambient air was used. Two adjustable parameters (heat and mass transfer coefficients) are used in the model. The values of these parameters were found larger than the values obtained in continental sites where dew forms with weak wind, thus emphasizing the peculiarities of dew formation in windy islands. When data are reduced with the calibration PMMA data, prototype P1 provided average water yields slightly larger than the enclosed prototype P2, a result that can be attributed to the influence of surface thermal radiation.

https://link.springer.com/article/10.1007/s40899-015-0038-z
A review: dew water collection from radiative passive collectors to recent developments of active collectors
B. Khalil, et al.

https://www.researchgate.net/publication/277300109_Making_Cheap_Drinking_Water_from_Air
Making Cheap Drinking Water from Air
Herman Vogel
[ PDF ]

Abstract -- How can we best apply basic technology to assist the underprivileged and/or the recent disaster-hit countries like Haiti? Daily hygiene and nourishment are among the top needs for disaster ridden regions! Simply put, no water means no hygiene and death. The Romans understood that over two millennia ago … and created their complexly beautiful aqueduct networks for handling both fresh and wastewater! Other ingenious water systems like “air wells” have been found in the city of Theodosia (cf: discovered in 1900 by Zibold, see Zibold’s Collectors/Dehumidifiers) dating back to Greco-Roman times during the Byzantine Empire. These were strictly passive systems that naturally dehumidified air, collecting its potable water in underground basins.

https://www.nature.com/articles/2071173a0
Irrigation of Plants with Atmospheric Water within the Desert
I. GINDEL

https://www.youtube.com/watch?v=v7Fu0dp3iB8
Air Well Concept - On-Going Research // Extreme Budget

https://iwaponline.com/ws/article/24/11/3810/105774/Atmospheric-water-harvesting-as-a-sustainable-and
Atmospheric water harvesting as a sustainable and resilient resource in arid climates: gaining insights from ancient techniques
Nathalie Verbrugghe, Ahmed Z. Khan

Abstract -- Fog and dew, or atmospheric moisture, are valuable complementary resources. Ancient civilisations exploited these resources in harmony with the environment, though information on their techniques is fragmented. This review provides insights into the efficiency, evolution, and relevance of ancient atmospheric water harvesting (AWH) techniques from 5000 B.C. to the 1900s, alongside modern techniques. An analytical framework and assessment are presented to deduce their viability for replication, revival, restoration, or redevelopment. Modern fog collectors yield an average value of 3–10 L/m2/day and dew collectors 0.3–0.6 L/m2/day. Ancient fog collectors from Mexico and Chile resembled modern collectors, while fog drip from trees offers a natural alternative, collecting 10 L/m2/day. The stone drip method shows potential in urban areas with extensive concrete surfaces. Ancient dew collection techniques include alchemists' dew collectors, lithic mulching for soil water conservation, dew ponds for water retention, and stone-pile condensers, which collected up to 360 L/day. Air wells, however, were less effective. Ancient AWH techniques offer valuable insights and can effectively supplement modern collectors, enhancing resilience and water security, especially in arid regions. Implementing AWH techniques provides sustainable, decentralised, nature-based strategies on a micro and macro scale for mitigating contemporary water shortages amidst increasing climate challenges.

https://doi.org/10.2166/aqua.2018.174
Journal of Water Supply: Research and Technology-Aqua (2018) 67 (4): 357–374.
Roof-integrated dew water harvesting in Combarbalá, Chile
Danilo Carvajal; et al.

Abstract -- Dew harvesting can be a supplementary source of freshwater in semiarid and arid areas. Several experiments on small-scale dew condensers (usually of 1 m2) have been carried out in many places in the world; however, few experiments have been conducted on large-scale collectors integrated into buildings. This work aims to assess one year of dew water harvesting in Combarbalá (Chile) using a painted galvanised steel roof as collecting surface. The roof (36 m2) was coated with a high-infrared-emissivity paint containing aluminosilicate minerals (OPUR, France). Dew measurements were conducted daily from September 2014 to August 2015. The dew yield and its relationship with meteorological variables were analysed. The results show that despite the low nocturnal relative humidity throughout the year (average: 48%), dew collection occurred on 56.1% of the recorded days. The daily average collection rate was 1.9 L d−1, with a maximum of 15 L d−1. The maximum daily dew yield is correlated strongly with relative humidity and correlated weakly with air temperature and wind speed. Considering the same rooftop can collect dew and rain, it was estimated that over one year dew water could contribute to roughly 8.2% of the total water collected, considering both sources.

https://doi.org/10.2166/aqua.2007.045
Journal of Water Supply: Research and Technology-Aqua (2007) 56 (4): 275–280.
Feasibility of fog water collection: a case study from Oman
Sabah A. Abdul-Wahab, et al.

Abstract -- The aim of this study was to assess different fog collectors in certain jabal (i.e. mountainous) areas in the Dhofar Region of the Sultanate of Oman which experience fog resulting from the Indian monsoons. A further aim was to provide fog collectors in the close vicinity of houses in the mountains to directly meet the needs of the local residents. Experiments were conducted using three fog collectors with different mesh materials namely; air conditioner filter (AC; 6 m × 2.8 m), green shade mesh (12 m × 3 m), and aluminum shade mesh (12 m × 3 m). The collectors were constructed close to the point of use. This reduced the costs as the installation of pipelines would not be needed to deliver the water. The results showed that all fog collectors proved to be very effective in fog water collection. Among all of them, the AC filter proved to be the most effective. The total fog water collected during the period of 77 days by AC filter, green shade mesh, and aluminum shade mesh was 995, 880, and 753 L/m2, respectively. This paper concludes with a set of recommendations for further in depth assessment of the qualitative and quantitative aspects of this water collection technology.

https://iwaponline.com/ws/article/22/1/874/83172/Potential-of-harvesting-water-from-fog-and-dew
Potential of harvesting water from fog and dew water over semi-arid and arid regions in Syria
Majd M. Khalil, et al.

Abstract -- Water is a significant primary resource on the Earth's surface. Fresh water is essential for human beings and for the stability and sustainable development of any nation. Many regions in the interior of Syria have an insufficient water balance. This has caused severe shortages of freshwater as a result of climate change. Syria's main source of fresh water, rivers and groundwater, suffers from low levels due to the lack of rainfall amounts. The war in Syria exacerbated water stress, in particular the effects of the war on water sources such as the Euphrates River and the ‘Feijah’ source that feeds the capital Damascus. All of this has prompted us to seek other non-traditional sources such as atmospheric water, which is a renewable and relatively clean source. This paper is considered to be the first of its kind in Syria. Experimental results from semi-arid and arid regions have shown good potential for harvesting dew and fog water as a supplementary and complementary source to the existing freshwater supply.

https://iwaponline.com/ws/article/23/9/3675/97029/Fog-water-harvesting-potential-and-its-use-in
Water Supply (2023) 23 (9): 3675–3693.
Fog water harvesting potential and its use in supplementary irrigation of rainfed crops (winter wheat) in Abi-beyglu, Ardabil (Iran)
Amin Kanooni, Mohammad Reza Kohan

Abstract -- In arid and semi-arid areas where available water resources are very limited, the application of unconventional sources of water like the fog is of paramount importance. In this paper, the feasibility of using a standard fog collector (SFC) to collect fog water for complementary irrigation of rainfed wheat in the Abi-beyglu area was investigated. For this purpose, collected water volume was measured on a daily basis during fog time in 2021. The water demand of the winter wheat was estimated by the FAO Penman–Monteith equation under dry and normal conditions. Then the contribution of the collected water to supply the water demand of the wheat and the resultant increase in the yield under two different scenarios, namely complementary irrigation with 30 and 60 mm of collected water, was estimated using the AquaCrop model. Results showed that it is feasible to obtain an average water production of 3.6 L/m2/day over the studied period. Upon irrigation with 30 and 60 mm of collected water under dry and normal conditions, 26 and 34% of the water deficiency for wheat farming was supplied, leading to increased crop yields by 0.6 and 1.7 ton/ha, respectively.

https://iwaponline.com/ws/article/22/1/697/83295/Analysis-of-different-condensing-surfaces-for-dew
https://doi.org/10.2166/ws.2021.242
Water Supply (2022) 22 (1): 697–706.
Analysis of different condensing surfaces for dew harvesting
Larissa Corraide da Silva, et al.

Abstract -- Due to water shortages in several places in the world, alternative water sources such as atmospheric water and greywater have been studied. Dew water harvesting by passive radiative cooling is an unconventional water source that is easy to use, install, and shows great potential in several places in the world. This paper aims to experimentally evaluate the dew yield through passive radiative cooling in Vicosa city, Minas Gerais, Brazil by using standard white plastic for dew harvesting, developed by the International Organization for Dew Utilization (OPUR), polypropylene plastic, black plastic, packaging tape, and anodized aluminum as condensing surfaces during two different periods. The polypropylene plastic and packing tape materials used in this present research have not been researched before in the literature. However, they have demonstrated potential for harvesting dew. As a result, the average water collected was, respectively, 0.151, 0.135, 0.140, 0.127, and 0.046 mm/night using the OPUR standard plastic, polypropylene plastic, black plastic, and packaging tape, and anodized aluminum as condensing surfaces. Although relatively small water volumes were harvested, this water should not be neglected since it can supplement the water demand for irrigation, human and animal consumption, among other uses in drought periods.

https://interestingengineering.com/lists/everything-you-need-to-know-about-air-to-water-devices
Here Are the Most Advanced Methods to Extract Plentiful Water From Thin Air
Turns out, the moisture farms in Star Wars might be possible.
Christopher McFadden

https://www.darpa.mil/research/programs/atmospheric-water-extraction
AWE: Atmospheric Water Extraction

Summary
Water transport is as mission-critical and as logistically challenging as fuel transport for the U.S. military. Meeting deployed military water needs requires equipment resources, consumes fuel, and endangers personnel.

The goal of DARPA’s Atmospheric Water Extraction (AWE) program is to provide potable freshwater for a range of military, stabilization, and humanitarian needs through the development of small, lightweight, low-powered, distributable systems that extract potable water from the atmosphere to meet the drinking needs of individuals and groups, even in extremely arid climates.

AWE seeks to develop next-generation, scalable sorbent materials that can rapidly extract water from ambient air and leverage advanced modeling, innovative engineering, and additive manufacturing methods to achieve a substantial reduction in the size, weight, and power (SWaP) requirements compared to current atmospheric water generation technologies.

AWE will address water needs in two tracks: expeditionary and stabilization. The expeditionary unit will provide sufficient drinking water for an individual warfighter, with SWaP parameters restricted by the need for portability and operation in austere environments.

The stabilization device will provide the daily drinking needs for up to ~150 people (i.e., a company or humanitarian mission), with SWaP requirements tailored to resources available to missions of that scale.

https://www.reuters.com/technology/spanish-engineers-extract-drinking-water-thin-air-2021-08-04/
Spanish engineers extract drinking water from thin air
Mariano Valladolid, Jon Nazca

A Spanish company has devised a system to extract drinking water from thin air to supply arid regions where people are in desperate need.
"The goal is to help people," said Enrique Veiga, the 82-year-old engineer who invented the machine during a harsh drought in southern Spain in the 1990s. "The goal is to get to places like refugee camps that don't have drinking water."
The devices made by his company, Aquaer, are already delivering clean, safe water to communities in Namibia and a Lebanese refugee camp...
While other water generators based on similar technology require high ambient humidity and low temperatures to function effectively, Veiga's machines work in temperatures of up to 40 Celsius (104F) and can handle humidity of between 10% and 15%.
A small machine can produce 50-75 litres a day, and be easily carried on a trolley, but bigger versions can produce up to 5,000 litres a day.

https://www.oas.org/dsd/publications/unit/oea59e/ch12.htm
1.3 Fog harvesting

This innovative technology is based on the fact that water can be collected from fogs under favorable climatic conditions. Fogs are defined as a mass of water vapor condensed into small water droplets at, or just above, the Earth's surface. The small water droplets present in the fog precipitate when they come in contact with objects. The frequent fogs that occur in the arid coastal areas of Peru and Chile are traditionally known as camanchacas. These fogs have the potential to provide an alternative source of freshwater in this otherwise dry region if harvested through the use of simple and low-cost collection systems known as fog collectors. Present research suggests that fog collectors work best in coastal areas where the water can be harvested as the fog moves inland driven by the wind. However, the technology could also potentially supply water for multiple uses in mountainous areas should the water present in stratocumulus clouds, at altitudes of approximately 400 m to 1 200 m, be harvested. ...

https://www.sciencedirect.com/science/article/abs/pii/0169809589900367
Atmospheric Research. Volume 24, Issues 1–4, December 1989, Pages 53-69
The collection efficiency of a massive fog collector
Robert S. Schemenauer, Paul I. Joe

Abstract -- Very large (48 m2) fog-water collectors are being used on the coastal mountains in northern Chile to generate water. The microphysical characteristics of the high elevation fog (camanchaca) have been examined and the collection efficiency of the collectors measured. The camanchaca exhibits characteristics of clouds, reflecting its source as a marine stratocumulus deck. Droplet mean volume diameters (MVD) in ten cases ranged from 10.8 to 15.3 μm. Droplet concentrations were typically 400 cm−3 with fog liquid water contents ranging from 0.22 to 0.73 g m−3.

The large fog-water collectors consist of a double layer of mesh made from a 1-mm wide flat polypropylene ribbon. The theoretical collection efficiencies of a 1-mm wide ribbon, for droplets with the observed MVD, at wind speeds from 2 to 8 m s−1, are 75 to 95%. The field measurements of the collection efficiency of the mesh at the centerline of a large collector gave values of ∼66% (3.5–6.5 m s−1; 11 μm MVD). This is in good agreement with the theoretical value for a single ribbon once the areal coverage of the mesh is taken into account. At lower windspeeds, the measured collection efficiencies dropped to ∼26% (1.9 m s−1; 15 μm MVD). A simple parameterization of the mesh collection efficiency allowed some properties of meshes to be examined, e.g. the mesh shows a marked decrease in droplet collection as the ribbon width increased while maintaining a constant percentage areal coverage.

The measured water output from the large collector was 2.9 times lower than predicted using the measured amount of water removed at the centerline and the wind speed 6m upstream. This implies a large-collector efficiency of only ∼20%. This low value may result from a lowering of wind speed as the fog approaches the mesh, a reduced collection efficiency away from the centerline, and water losses in the system.

https://www.sciencedirect.com/science/article/abs/pii/S0168192309001592
Agricultural and Forest Meteorology, Volume 149, Issue 11, 3 November 2009, Pages 1896-1906
Prospective use of collected fog water in the restoration of degraded burned areas under dry Mediterranean conditions
María J. Estrela, et al.

Abstract -- A mountainous plot located in the interior of the Valencia region (east coast of the Iberian Peninsula) was identified for reforestation using the fog-water collection potential prevailing in the area. Fog data were obtained by means of an instrument ensemble consisting of a passive cylindrical fog-water collector, a rain gauge, a wind direction and velocity sensor and a temperature and humidity probe. Preliminary results gave rise to the additional deployment of a low-cost 18-m2 flat-panel collector connected to three 1000-l tanks for larger scale fog-water collection and storage. The 2007 annual rate of fog water that could be derived from the instrument ensemble amounted to 3.3 l/m2/day, which turn out to fill up the storage tanks completely in only 5 months, even though the flat-panel collector could not be operative 100% of the time. The study made use of the in situ stored water and a micro-irrigation network to irrigate a plot of reforestation seedlings through small water pulses localized deep in the planting hole during the summer dry period. Until the present, this forest location had always shown a difficult self-recovery due to the high level of land degradation resulting from recurrent forest fires in the past. Results indicate that survival rates and seedling performance of the two species planted, Pinus pinaster and Quercus ilex, improved with the use of small timely waterings and additional treatments with composted biosolid.

https://www.sciencedirect.com/science/article/abs/pii/S0169809502000960
Atmospheric Research, Volume 64, Issues 1–4, September–October 2002, Pages 251-259
Exploring fog as a supplementary water source in Namibia
E.S Shanyengana, et al.

Abstract -- Namibia is an arid country where many rural and urban centres depend on ephemeral rivers for their water supply. These water sources are, however, limited and display seasonal salinisation. Fog occurs along the coast and extends for some distance inland, and it could be used as a source of drinking water. Data on groundwater salinisation and fog deposition were collected at villages of the indigenous communities and at the Gobabeb Training and Research Centre (GTRC) in the Central Namib Desert. Fog collection experiments were done with Standard Fog Collectors (SFCs) and 1-m2 fog collectors made from the Raschel mesh that is used in SFCs from 1996 onwards. The results indicate that fog occurs throughout the year and that it has low major ion concentrations (chemical composition). The period of high fog deposition coincides with that of high groundwater salinity and would suit mixing of the two waters to provide water of good drinking quality to people in these areas. In conclusion, fog is a viable source of water in the Namib and could supplement traditional sources in rural settlements and perhaps also in urban water supply schemes in this region as in other parts of the world where it is used as a source of drinking water.

https://www.sciencedirect.com/science/article/abs/pii/S0169809502000947
Atmospheric Research, Volume 64, Issues 1–4, September–October 2002, Pages 227-238
The implementation of fog water collection systems in South Africa
J Olivier, C.J de Rautenbach

Abstract -- Two fog water collection systems (FWCS) have been implemented in South Africa. Both are located in areas where communities experience acute water shortages but which are prone to frequent fog episodes. The first was located at a high elevation site at the Tshanowa Junior Primary (JP) School in the Soutpansberg located in the Northern Province and the other near a small rural community at Lepelfontein along the West Coast. The former represents a mountainous site, while the latter is located on a low level coastal plain. The principal aim of the projects was to implement operational FWCSs to supply the communities with water. During the period 1999 to 2001 the total recorded cloud water yields at the Tshanowa JP School and Lepelfontein water collection sites were in the region of 72 422 and 148 691 l, respectively. This is equivalent to just over 2 l m−2 day−1 at the Tshanowa JP School and 4.6 l m−2 day−1 at the Lepelfontein site. Despite the relatively low average daily yields recorded, the total water volume collected on a particular day may be considerable. In fact, at both sites the maximum daily yield exceeded 3800 l. Fog deposition accounted for around 25% and 88% of the total water yield measured at the Tshanowa JP School and Lepelfontein sites, respectively. Both experiments indicated that fog water collection holds considerable potential as an alternative water source in the mountainous regions and along the West Coast of South Africa.

https://www.sciencedirect.com/science/article/abs/pii/S0169809507002116
Atmospheric Research, Volume 87, Issues 3–4, March 2008, Pages 324-337
Fog collection in the western Mediterranean basin (Valencia region, Spain)
María J. Estrela, et al.

Abstract --Four different mountainous locations were selected in the Valencia region, East coast of the Iberian Peninsula, for fog water collection studies. Data for 2004 were obtained by means of an instrument ensemble consisting essentially of a passive cylindrical fog water collector, a raingauge, a wind direction and velocity sensor and a temperature and humidity probe. An approximate data reduction technique was also found for this specific ensemble to eliminate the simultaneous rain water component from the fog water measurements. Main results indicate that fog water collection holds significant potential in this region, and especially for southern locations. Annual rates of fog water yield can be as high as 7.0 l/m2/day in the southern locations, in contrast to 2.0 l/m2/day collected at one site in a northern location. The highest summer fog water yield was 4.6 l/m2/day, a relatively large value. Except for the summer period, fog episodes delivering sizeable water volumes are inherently coupled to rainfall. Hourly frequencies of fog collection were also examined to show a distinct daily cycle in summer, denoting orographic fog formation during this period. Lastly, winds were analysed to resolve the most suitable directions for fog collector alignment.

https://www.nature.com/articles/s41467-021-23174-0
Nature Communications volume 12, Article number: 2797 (2021)
All-day fresh water harvesting by microstructured hydrogel membranes
Ye Shi, Ognjen Ilic, Harry A. Atwater & Julia R. Greer

Abstract -- Solar steam water purification and fog collection are two independent processes that could enable abundant fresh water generation. We developed a hydrogel membrane that contains hierarchical three-dimensional microstructures with high surface area that combines both functions and serves as an all-day fresh water harvester. At night, the hydrogel membrane efficiently captures fog droplets and directionally transports them to a storage vessel. During the daytime, it acts as an interfacial solar steam generator and achieves a high evaporation rate of 3.64 kg m−2 h−1 under 1 sun enabled by improved thermal/vapor flow management. With a homemade rooftop water harvesting system, this hydrogel membrane can produce fresh water with a daily yield of ~34 L m−2 in an outdoor test, which demonstrates its potential for global water scarcity relief.

https://pubs.acs.org/doi/10.1021/acsami.7b17488
Fog Harvesting with Harps
Weiwei Shi, et al.

Abstract -- Fog harvesting is a useful technique for obtaining fresh water in arid climates. The wire meshes currently utilized for fog harvesting suffer from dual constraints: coarse meshes cannot efficiently capture microscopic fog droplets, whereas fine meshes suffer from clogging issues. Here, we design and fabricate fog harvesters comprising an array of vertical wires, which we call “fog harps”. Under controlled laboratory conditions, the fog-harvesting rates for fog harps with three different wire diameters were compared to conventional meshes of equivalent dimensions. As expected for the mesh structures, the mid-sized wires exhibited the largest fog collection rate, with a drop-off in performance for the fine or coarse meshes. In contrast, the fog-harvesting rate continually increased with decreasing wire diameter for the fog harps due to efficient droplet shedding that prevented clogging. This resulted in a 3-fold enhancement in the fog-harvesting rate for the harp design compared to an equivalent mesh.

https://en.wikipedia.org/wiki/Air_well_(condenser)
AirWells

https://www.youtube.com/watch?v=vqKDNwGgN-w
How To Get Water From The Air Around You // TNT Omnibus

https://www.sciencedirect.com/science/article/abs/pii/0022169495029397?via%3Dihub
Water recovery from dew
V.S. Nikolayev, D. Beysens, A. Gioda, I. Milimouka, E. Katiushin, J.-P. Morel

Abstract -- The recovery of clean water from dew has remained a longstanding challenge in many places all around the world. It is currently believed that the ancient Greeks succeeded in recovering atmospheric water vapour on a scale large enough to supply water to the city of Theodosia (presently Feodosia, Crimea, Ukraine). Several attempts were made in the early 20th century to build artificial dew-catching constructions which were subsequently abandoned because of their low yield. The idea of dew collection is revised in the fight of recent investigations of the basic physical phenomena involved in the formation of dew. A model for calculating condensation rates on real dew condensers is proposed. Some suggestions for the ‘ideal’ condenser are formulated.

https://www.amusingplanet.com/2016/08/achille-knapens-air-well.html
Achille Knapen’s Air Well
Kaushik Patowary

https://www.researchgate.net/publication/341480904_Large_Scale_Dew_Collection_as_a_Source_of_Fresh_Water_Supply
Large Scale Dew Collection as a Source of Fresh Water Supply
Anil Rajvanshi

Abatract -- A scheme for large scale dew collection as a source of freshwater supply is outlined in the present paper. The scheme envisages bringing cold seawater (5°C) from about 500 meters depth and about 5 km from the shore, in 4, 1.22 m diameter plastic pipes. It then passes through a heat exchanger field with an area of 1.29 × 105 m2 (1.39 × 106 ft2) where it condenses 643m3 of dew over the 24 hour period. The pumping of seawater from the sea and through the field is accomplished by three 200 kW wind machines. Technical and economical feasibility of the scheme is analysed and the possibility of marine culture as a source of food is explored. The present scheme is economically not feasible as compared to a reverse osmosis facility of equivalent capacity.

https://interestingengineering.com/lists/everything-you-need-to-know-about-air-to-water-devices
Here Are the Most Advanced Methods to Extract Plentiful Water From Thin Air
Turns out, the moisture farms in Star Wars might be possible.
Christopher McFadden

https://www.tsunamiproducts.com/
Tsunami Products
At Tsunami Products, we design and build machines that extract water from humidity in the air — efficiently and economically.

https://www.newscientist.com/article/2177538-nanofibre-net-draws-drinking-water-from-the-air-for-drought-hit-people/
Nanofibre net draws drinking water from the air for drought-hit people
Frank Swain

...Fog nets usually consist of a sheet of polythene mesh strung between two poles. Passing water vapour condenses on the small fibres and trickles down into collection bottles below.

However, the yield of these nets is often limited and the water only flows on foggy days. The technology is also restricted to mountainous regions where warm, wet air arriving from the coast is forced up steep slopes, where it cools and condenses as fog.

Shing-Chung Josh Wong at the University of Akron in Ohio, US and his team created a new material that they believe will be a large improvement. They used electrospun polymers – a technique which allowed them to create nanoscale fibres. These are tangled around fragments of expanded graphite, like spaghetti around meatballs. The fibres provide a large surface area for droplets to condense onto, and the graphite encourages the water to drip out of the material when it is squeezed or heated.

Wong says that harvesters made with these nanofibres could yield up to 180 litres of water per square metre every day. In comparison, a commercial system currently in use in Morocco only produces around 30 litres per square metre per day.

US2023084610 -- FRESHWATER HARVESTING ASSEMBLY UTILIZING WATER-SORPTION MATERIAL WITHIN HIERARCHICAL COMPONENT

https://www.darpa.mil/research/programs/atmospheric-water-extraction
AWE: Atmospheric Water Extraction

Summary -- Water transport is as mission-critical and as logistically challenging as fuel transport for the U.S. military. Meeting deployed military water needs requires equipment resources, consumes fuel, and endangers personnel.

The goal of DARPA’s Atmospheric Water Extraction (AWE) program is to provide potable freshwater for a range of military, stabilization, and humanitarian needs through the development of small, lightweight, low-powered, distributable systems that extract potable water from the atmosphere to meet the drinking needs of individuals and groups, even in extremely arid climates.

AWE seeks to develop next-generation, scalable sorbent materials that can rapidly extract water from ambient air and leverage advanced modeling, innovative engineering, and additive manufacturing methods to achieve a substantial reduction in the size, weight, and power (SWaP) requirements compared to current atmospheric water generation technologies.

AWE will address water needs in two tracks: expeditionary and stabilization. The expeditionary unit will provide sufficient drinking water for an individual warfighter, with SWaP parameters restricted by the need for portability and operation in austere environments.

The stabilization device will provide the daily drinking needs for up to ~150 people (i.e., a company or humanitarian mission), with SWaP requirements tailored to resources available to missions of that scale.

https://www.sciencedirect.com/science/article/abs/pii/S0168192309001592
Agricultural and Forest Meteorology ,Volume 149, Issue 11, 3 November 2009, Pages 1896-1906
Prospective use of collected fog water in the restoration of degraded burned areas under dry Mediterranean conditions
María J. Estrela, et al.

Abstract -- A mountainous plot located in the interior of the Valencia region (east coast of the Iberian Peninsula) was identified for reforestation using the fog-water collection potential prevailing in the area. Fog data were obtained by means of an instrument ensemble consisting of a passive cylindrical fog-water collector, a rain gauge, a wind direction and velocity sensor and a temperature and humidity probe. Preliminary results gave rise to the additional deployment of a low-cost 18-m2 flat-panel collector connected to three 1000-l tanks for larger scale fog-water collection and storage. The 2007 annual rate of fog water that could be derived from the instrument ensemble amounted to 3.3 l/m2/day, which turn out to fill up the storage tanks completely in only 5 months, even though the flat-panel collector could not be operative 100% of the time. The study made use of the in situ stored water and a micro-irrigation network to irrigate a plot of reforestation seedlings through small water pulses localized deep in the planting hole during the summer dry period. Until the present, this forest location had always shown a difficult self-recovery due to the high level of land degradation resulting from recurrent forest fires in the past. Results indicate that survival rates and seedling performance of the two species planted, Pinus pinaster and Quercus ilex, improved with the use of small timely waterings and additional treatments with composted biosolid.

https://www.sciencedirect.com/science/article/abs/pii/S0169809502000960
Atmospheric Research, Volume 64, Issues 1–4, September–October 2002, Pages 251-259
Exploring fog as a supplementary water source in Namibia
E.S Shanyengana, et al.

Abstract -- Namibia is an arid country where many rural and urban centres depend on ephemeral rivers for their water supply. These water sources are, however, limited and display seasonal salinisation. Fog occurs along the coast and extends for some distance inland, and it could be used as a source of drinking water. Data on groundwater salinisation and fog deposition were collected at villages of the indigenous communities and at the Gobabeb Training and Research Centre (GTRC) in the Central Namib Desert. Fog collection experiments were done with Standard Fog Collectors (SFCs) and 1-m2 fog collectors made from the Raschel mesh that is used in SFCs from 1996 onwards. The results indicate that fog occurs throughout the year and that it has low major ion concentrations (chemical composition). The period of high fog deposition coincides with that of high groundwater salinity and would suit mixing of the two waters to provide water of good drinking quality to people in these areas. In conclusion, fog is a viable source of water in the Namib and could supplement traditional sources in rural settlements and perhaps also in urban water supply schemes in this region as in other parts of the world where it is used as a source of drinking water.

https://www.sciencedirect.com/science/article/abs/pii/S0169809502000947
Atmospheric Research, Volume 64, Issues 1–4, September–October 2002, Pages 227-238
The implementation of fog water collection systems in South Africa
J Olivier, C.J de Rautenbach

Abstract -- Two fog water collection systems (FWCS) have been implemented in South Africa. Both are located in areas where communities experience acute water shortages but which are prone to frequent fog episodes. The first was located at a high elevation site at the Tshanowa Junior Primary (JP) School in the Soutpansberg located in the Northern Province and the other near a small rural community at Lepelfontein along the West Coast. The former represents a mountainous site, while the latter is located on a low level coastal plain. The principal aim of the projects was to implement operational FWCSs to supply the communities with water. During the period 1999 to 2001 the total recorded cloud water yields at the Tshanowa JP School and Lepelfontein water collection sites were in the region of 72 422 and 148 691 l, respectively. This is equivalent to just over 2 l m−2 day−1 at the Tshanowa JP School and 4.6 l m−2 day−1 at the Lepelfontein site. Despite the relatively low average daily yields recorded, the total water volume collected on a particular day may be considerable. In fact, at both sites the maximum daily yield exceeded 3800 l. Fog deposition accounted for around 25% and 88% of the total water yield measured at the Tshanowa JP School and Lepelfontein sites, respectively. Both experiments indicated that fog water collection holds considerable potential as an alternative water source in the mountainous regions and along the West Coast of South Africa.

https://www.sciencedirect.com/science/article/abs/pii/S0169809507002116
Atmospheric Research, Volume 87, Issues 3–4, March 2008, Pages 324-337
Fog collection in the western Mediterranean basin (Valencia region, Spain)
María J. Estrela, et al.

Abstract -- Four different mountainous locations were selected in the Valencia region, East coast of the Iberian Peninsula, for fog water collection studies. Data for 2004 were obtained by means of an instrument ensemble consisting essentially of a passive cylindrical fog water collector, a raingauge, a wind direction and velocity sensor and a temperature and humidity probe. An approximate data reduction technique was also found for this specific ensemble to eliminate the simultaneous rain water component from the fog water measurements. Main results indicate that fog water collection holds significant potential in this region, and especially for southern locations. Annual rates of fog water yield can be as high as 7.0 l/m2/day in the southern locations, in contrast to 2.0 l/m2/day collected at one site in a northern location. The highest summer fog water yield was 4.6 l/m2/day, a relatively large value. Except for the summer period, fog episodes delivering sizeable water volumes are inherently coupled to rainfall. Hourly frequencies of fog collection were also examined to show a distinct daily cycle in summer, denoting orographic fog formation during this period. Lastly, winds were analysed to resolve the most suitable directions for fog collector alignment.

https://www.nature.com/articles/s41467-021-23174-0
Nature Communications volume 12, Article number: 2797 (2021)
All-day fresh water harvesting by microstructured hydrogel membranes
Ye Shi, Ognjen Ilic, Harry A. Atwater & Julia R. Greer

Abstract -- Solar steam water purification and fog collection are two independent processes that could enable abundant fresh water generation. We developed a hydrogel membrane that contains hierarchical three-dimensional microstructures with high surface area that combines both functions and serves as an all-day fresh water harvester. At night, the hydrogel membrane efficiently captures fog droplets and directionally transports them to a storage vessel. During the daytime, it acts as an interfacial solar steam generator and achieves a high evaporation rate of 3.64 kg m−2 h−1 under 1 sun enabled by improved thermal/vapor flow management. With a homemade rooftop water harvesting system, this hydrogel membrane can produce fresh water with a daily yield of ~34 L m−2 in an outdoor test, which demonstrates its potential for global water scarcity relief.

https://pubs.acs.org/doi/10.1021/acsami.7b17488
Fog Harvesting with Harps
Weiwei Shi, et al.

Abstract -- Fog harvesting is a useful technique for obtaining fresh water in arid climates. The wire meshes currently utilized for fog harvesting suffer from dual constraints: coarse meshes cannot efficiently capture microscopic fog droplets, whereas fine meshes suffer from clogging issues. Here, we design and fabricate fog harvesters comprising an array of vertical wires, which we call “fog harps”. Under controlled laboratory conditions, the fog-harvesting rates for fog harps with three different wire diameters were compared to conventional meshes of equivalent dimensions. As expected for the mesh structures, the mid-sized wires exhibited the largest fog collection rate, with a drop-off in performance for the fine or coarse meshes. In contrast, the fog-harvesting rate continually increased with decreasing wire diameter for the fog harps due to efficient droplet shedding that prevented clogging. This resulted in a 3-fold enhancement in the fog-harvesting rate for the harp design compared to an equivalent mesh.

https://news.mit.edu/2013/how-to-get-fresh-water-out-of-thin-air-0830
How to get fresh water out of thin air
Fog-harvesting system developed by MIT and Chilean researchers could provide potable water for the world’s driest regions.

...Fog-harvesting systems generally consist of a vertical mesh, sort of like an oversized tennis net. Key to efficient harvesting of the tiny airborne droplets of fog are three basic parameters, the researchers found: the size of the filaments in those nets, the size of the holes between those filaments, and the coating applied to the filaments.

Most existing systems turn out to be far from optimal, Park says. Made of woven polyolefin mesh — a kind of plastic that is easily available and inexpensive — they tend to have filaments and holes that are much too large. As a result, they may extract only about 2 percent of the water available in a mild fog condition, whereas the new research shows that a finer mesh could extract 10 percent or more, Park says. Multiple nets deployed one behind another could then extract even more, if so desired...
The researchers found that controlling the size and structure of the mesh and the physical and chemical composition of this coating was essential to increasing the fog-collecting efficiency. Detailed calculations and laboratory tests indicate that the best performance comes from a mesh made of stainless-steel filaments about three or four times the thickness of a human hair, and with a spacing of about twice that between fibers. In addition, the mesh is dip-coated, using a solution that decreases a characteristic called contact-angle hysteresis. This allows small droplets to more easily slide down into the collecting gutter as soon as they form, before the wind blows them off the surface and back into the fog stream...
...with the MIT-designed system, Park points out, 10 percent of the fog moisture in the air passing through the new fog collector system can potentially be captured...

Langmuir, Vol 29/Issue 43, July 29, 2013
Optimal Design of Permeable Fiber Network Structures for Fog Harvesting
Kyoo-Chul Park, et al.
Abstract -- Fog represents a large untapped source of potable water, especially in arid climates. Numerous plants and animals use textural and chemical features on their surfaces to harvest this precious resource. In this work, we investigate the influence of the surface wettability characteristics, length scale, and weave density on the fog-harvesting capability of woven meshes. We develop a combined hydrodynamic and surface wettability model to predict the overall fog-collection efficiency of the meshes and cast the findings in the form of a design chart. Two limiting surface wettability constraints govern the re-entrainment of collected droplets and clogging of mesh openings. Appropriate tuning of the wetting characteristics of the surfaces, reducing the wire radii, and optimizing the wire spacing all lead to more efficient fog collection. We use a family of coated meshes with a directed stream of fog droplets to simulate a natural foggy environment and demonstrate a five-fold enhancement in the fog-collecting efficiency of a conventional polyolefin mesh. The design rules developed in this work can be applied to select a mesh surface with optimal topography and wetting characteristics to harvest enhanced water fluxes over a wide range of natural convected fog environments.

WO2023230244 -- METHOD AND SYSTEM FOR FOG HARVESTING AND MIST ELIMINATION

https://www.academia.edu/86497437/Self_Sufficient_Atmospheric_Water_Generator_using_Renewable_Energy?email_work_card=view-paper
Self Sufficient Atmospheric Water Generator using Renewable Energy
By IRJET Journal
[ PDF ]

Abstract -- There is a saying, "water has only two aspects; when mixed with anything it's NEED, and when not it's LIFE". This paper sets forth a solution to assist the struggle against the scarcity of freshwater. Atmospheric Water Generators (AWG) are a promising technology solution to the water scarcity in the world. This paper takes into account that the AWG fulfills certain prerequisites of portability, simplicity, flexibility, maximize efficiency & minimize cost.

https://www.academia.edu/23216101/A_Project_on_Atmospheric_Water_Generator_with_the_Concept_of_Peltier_Effect?email_work_card=title
International Journal of Advanced Computer Research, A Project on Atmospheric Water Generator with the Concept of Peltier Effect
Project on Atmospheric Water Generator with the Concept of Peltier Effect
Vignesh Kumar, et al.
[ PDF ]

Abstract -- In many countries like India it is difficult to obtain water resources for irrigation or other purposes, especially in the arid regions. The problem of water scarcity is also observed in other places of the world due to lack of rainfall. However, in highly humid areas such as places close to the sea, water can be obtained by condensing the water vapour present in air. Here, the paper presents the method to develop a water condensation system based on thermoelectric cooler. The system consists of cooling elements, heat exchange unit and air circulation unit. A solar cell panel unit with a relevant high current output drives the cooling elements through a controlling circuit. Atmospheric Water Generator is a device that can convert atmospheric moisture directly into usable and even drinkable water. It is such a device which uses the principle of latent heat to convert molecules of water vapour into water droplets. It has been introduced a bit before, though it is not very common in India and some other countries. It has a great application standing on such age of technology where we all are running behind renewable sources. This paper also describes the experimental results and the system’s performance.

https://www.sciencedirect.com/science/article/pii/S2542435121001781
Joule, Volume 5, Issue 7, 2021, pp. 1678-1703
Adsorption-based atmospheric water harvesting
M. Ejeian, R.Z. Wang
[ PDF ]

Abstract -- In recent years, humidity has been introduced as a reliable source of water. Among the various technologies, adsorption-based atmospheric water harvesting (ABAWH) has shown apparent advantages, especially in arid areas. So far, most research in this field has been done on developing modern and efficient adsorbents. The difference in climatic conditions and applications makes it impossible to introduce an ideal adsorbent. While adsorption kinetics is preferred in quasi-continuous systems, adsorption capacity is more desired in discontinuous systems. Despite its crucial role, the adsorbent is only part of the process of converting moisture to liquid water in an ABAWH system. Multicycle systems, face challenges such as switching methods, sensible heat, and RH fluctuations. Additionally, in solar-powered systems, an auxiliary energy supply is necessary to continue the production process at night. Moreover, the desorption rate is limited by the distillation rate in the condenser. Using hybrid surfaces and supply cold sources can improve system performance. In this article, we have tried to consider the whole ABAWH system where structures, strategies, and components of a device in various applications, including drinking water, agriculture, and water recovery, have been examined, and the features, challenges, and path ahead of each have been described with examples and practical ideas. This article can guide designing and optimizing ABAWH devices toward widespread use of this technology.

https://www.sciencedirect.com/science/article/abs/pii/S0169809516302216
Atmospheric Research, Volume 182, 2016, pp. 156-162
Assessment of atmospheric moisture harvesting by direct cooling
Ben Gido, …, David M. Broday

Abstract -- The enormous amount of water vapor present in the atmosphere may serve as a potential water resource. An index is proposed for assessing the feasibility and energy requirements of atmospheric moisture harvesting by a direct cooling process. A climate-based analysis of different locations reveals the global potential of this process. We demonstrate that the Moisture Harvesting Index (MHI) can be used for assessing the energy requirements of atmospheric moisture harvesting. The efficiency of atmospheric moisture harvesting is highly weather and climate dependent, with the smallest estimated energy requirement found at the tropical regions of the Philippines (0.23 kW/L). Less favorable locations have much higher energy demands for the operation of an atmospheric moisture harvesting device. In such locations, using the MHI to select the optimal operation time periods (during the day and the year) can reduce the specific energy requirements of the process dramatically. Still, using current technology the energy requirement of atmospheric moisture harvesting by a direct air cooling process is significantly higher than of desalination by reverse osmosis.

https://www.sciencedirect.com/science/article/abs/pii/S0735193322000094
International Communications in Heat and Mass Transfer, Volume 132, 2022, Article 105887
Water production enhancement from the air moisture using nanofluids-experimental investigation and exergo-enviroeconomic analysis
Masoud Kaveh, …, Abdollah Khalesi Doust

Abstract -- Nowadays, the expansion of communities and population growth has further highlighted the need for clean water. To solve this problem, various methods have been proposed. Water extraction from the air moisture is of these methods which involve cooling the air to its dew point in which the moisture transforms from the gas to the liquid phase. In the present study, a device consisting of a refrigeration cycle and a moisture distillation cycle was designed to provide pure water from the air moisture. Additionally, it was tried to enhance the system performance by dispersing nanoparticles such as Cu and Al2O3 into the working fluid of the heat exchanger. In this study, the influence of various parameters (including inlet air velocity and ambient humidity) on the performance of the system was investigated. Finally, an exergo-enviroeconomic analysis was performed in terms of water production and cost. Based on the results, with increasing the air humidity from 40% to 60%, the amount of water production of the system raised from 0.5 to 1.8 cc/min. It was also observed that dispersion of Cu and Al2O3 nanoparticles enhanced the water production by around 43% and 29%, respectively. Moreover, an increment in inlet air velocity reduced the water production; while increasing the air humidity had a constructive effect on the system performance. The economic analysis indicated that the water production during a year increased by about 42% upon using Cu nanofluid as the working fluid of the distillation cycle which declined the water production cost by 32%.

https://scholar.google.ch/citations?view_op=view_citation&hl=en&user=2SLbtkUAAAAJ&citation_for_view=2SLbtkUAAAAJ:8k81kl-MbHgC
Angewandte Chemie, Volume 134, Issue 13, e202200271
Polyzwitterionic hydrogels for efficient atmospheric water harvesting

Chuxin Lei, Youhong Guo, Weixin Guan, Hengyi Lu, Wen Shi, Guihua Yu

Abstract -- Atmospheric water harvesting (AWH) is regarded as one of the promising strategies for freshwater production desirable to provide sustainable water for landlocked and arid regions. Hygroscopic materials have attracted widespread attention because of their water harvesting performance. However, the introduction of many inorganic salts often leads to aggregation and leakage issues in practical use. Here, polyzwitterionic hydrogels are developed as an effective AWH material platform. Via anti‐polyelectrolyte effects, the hygroscopic salt coordinated with polymer chains could capture moisture and enhance the swelling property, leading to a strong moisture sorption capacity. The hydrogel shows superior AWH performance (0.62 g g⁻¹, 120 minutes for equilibrium at 30 % relative humidity) and produces 5.87 L kg⁻¹ freshwater per day. It is anticipated that the polyzwitterionic hydrogels with unique salt …

https://scholar.google.ch/citations?view_op=view_citation&hl=en&user=2SLbtkUAAAAJ&citation_for_view=2SLbtkUAAAAJ:2osOgNQ5qMEC
Advanced Materials, Volume 34, Issue 12, Pages 2110079
Materials engineering for atmospheric water harvesting: progress and perspectives
Hengyi Lu, Wen Shi, Youhong Guo. Weixin Guan, Chuxin Lei, Guihua Yu

Abstract -- Atmospheric water harvesting (AWH) is emerging as a promising strategy to produce fresh water from abundant airborne moisture to overcome the global clean water shortage. The ubiquitous moisture resources allow AWH to be free from geographical restrictions and potentially realize decentralized applications, making it a vital parallel or supplementary freshwater production approach to liquid water resource?based technologies. Recent advances in regulating chemical properties and micro/nanostructures of moisture?harvesting materials have demonstrated new possibilities to promote enhanced device performance and new understandings. This perspective aims to provide a timely overview on the state?of?the?art materials design and how they serve as the active components in AWH. First, the key processes of AWH, including vapor condensation, droplet nucleation, growth, and departure are outlined, and …

https://scholar.google.ch/citations?view_op=view_citation&hl=en&user=2SLbtkUAAAAJ&citation_for_view=2SLbtkUAAAAJ:3fE2CSJIrl8C
Scalable super hygroscopic polymer films for sustainable moisture harvesting in arid environments
Youhong Guo, Weixin Guan, Chuxin Lei, Hengyi Lu, Wen Shi, Guihua Yu

Abstract -- Extracting ubiquitous atmospheric water is a sustainable strategy to enable decentralized access to safely managed water but remains challenging due to its limited daily water output at low relative humidity (?30% RH). Here, we report super hygroscopic polymer films (SHPFs) composed of renewable biomasses and hygroscopic salt, exhibiting high water uptake of 0.64–0.96?g?g?1 at 15–30% RH. Konjac glucomannan facilitates the highly porous structures with enlarged air-polymer interfaces for active moisture capture and water vapor transport. Thermoresponsive hydroxypropyl cellulose enables phase transition at a low temperature to assist the release of collected water via hydrophobic interactions. With rapid sorption-desorption kinetics, SHPFs operate 14–24 cycles per day in arid environments, equivalent to a water yield of 5.8–13.3?L?kg?1. Synthesized via a simple casting method using sustainable …

https://scholar.google.ch/citations?view_op=view_citation&hl=en&user=2SLbtkUAAAAJ&citation_for_view=2SLbtkUAAAAJ:8k81kl-MbHgC
Angewandte Chemie, Volume 134, Issue 13, e202200271
Polyzwitterionic hydrogels for efficient atmospheric water harvesting

Chuxin Lei, Youhong Guo, Weixin Guan, Hengyi Lu, Wen Shi, Guihua Yu

Abstract -- Atmospheric water harvesting (AWH) is regarded as one of the promising strategies for freshwater production desirable to provide sustainable water for landlocked and arid regions. Hygroscopic materials have attracted widespread attention because of their water harvesting performance. However, the introduction of many inorganic salts often leads to aggregation and leakage issues in practical use. Here, polyzwitterionic hydrogels are developed as an effective AWH material platform. Via anti‐polyelectrolyte effects, the hygroscopic salt coordinated with polymer chains could capture moisture and enhance the swelling property, leading to a strong moisture sorption capacity. The hydrogel shows superior AWH performance (0.62 g g⁻¹, 120 minutes for equilibrium at 30 % relative humidity) and produces 5.87 L kg⁻¹ freshwater per day. It is anticipated that the polyzwitterionic hydrogels with unique salt …

https://interestingengineering.com/innovation/nanomaterial-pulls-water-from-air
New physics-defying nanomaterial gathers water from air directly

The material works through capillary condensation, a phenomenon where water vapor turns into liquid within microscopic pores, even when the humidity is relatively low.

...The researchers at the University of Pennsylvania School of Engineering and Applied Science were reportedly testing a mix of hydrophilic nanopores and hydrophobic polymers when they unexpectedly noticed water droplets forming on the material’s surface.

“We weren’t even trying to collect water,” Daeyeon Lee, a Russell Pearce and Elizabeth Cr Simian Heuer professor in chemical and biomolecular engineering (CBE), said. “It didn’t make sense. That’s when we started asking questions.”

A passive water-harvesting platform
Upon analyzing the results, the team realized they had created a material with the perfect balance of water-attracting nanoparticles and water-repelling polyethylene, giving rise to its unusual behavior.

https://www.science.org/doi/10.1126/sciadv.adu8349
Amphiphilic nanopores that condense undersaturated water vapor and exude water droplets
Baekmin Q. Kim, et al

Abstract -- Condensation of water vapor in confined geometries, known as capillary condensation, is a fundamental phenomenon with far-reaching implications. While hydrophilic pores enable liquid formation from undersaturated vapor without energy input, the condensate typically remains confined, limiting practical utility. Here, we explore the use of amphiphilic nanoporous polymer-infiltrated nanoparticle films that condense and release liquid water under isothermal and undersaturated conditions. By tuning the polymer fraction and nanoparticle size, we optimize condensation and droplet formation. As vapor pressure increases, voids fill with condensate, which subsequently exudes onto the surface as microscopic droplets. This behavior, enabled by a balance of polymer hydrophobicity and capillarity, reveals how amphiphilic nanostructures can drive accessible water collection. Our findings provide design insights for materials supporting energy-efficient water harvesting and heat management without external input.

https://www.researchgate.net/publication/325847937
International Conference on Contemporary Affairs in Architecture and Urbanism (ICCAUA-2018) Architectural Facade Design Proposal for Water Production via Air Content
Doğuş Bodamyalızade, Halil Zafer Alibaba
[ PDF ]

Abstract -- The main aim of this article is to analyse current facade techniques, water producing systems and possible profits from the application of adequate facade designs which could produce water with the consideration of the needs of inhabitants. Nowadays for certain countries lacking the financial power to provide adequate water resources, the need of water harvesting becomes more crucial. The proposed water harvesting systems aim to increase the water resources by the application on the building’s facade. On the other hand, existing double skin facades have only been used for shading, ventilation or decorative purposes. This investigation focuses specifically on the design of the facade in terms of the production of water. The case study has taken place in North Cyprus, Nicosia. A selected area will be evaluated and the need of the water will be calculated then the proposal of the new facade model will be introduced. Most importantly this proposed facade model will meet the needs of water consumption of the inhabitants. It produces 420 litre water per day by using solar energy. With this system the application uses the sun energy to extract water from the air, also the application has potential to use as multi-functional purposes since it collects water via humidity with turbine systems, it collects up to 396 litres at temperatures between 86 degrees to 104 degrees (30 to 40 degrees Celsius) and between 80% and 90% relative humidity.

https://pmc.ncbi.nlm.nih.gov/articles/PMC10073925/
An overview of atmospheric water harvesting methods, the inevitable path of the future in water supply
Zahra Ahrestani, et al.
[ PDF ]

Abstract -- Although science has made great strides in recent years, access to fresh water remains a major challenge for humanity due to water shortage for two-thirds of the world's population. Limited access to fresh water becomes more difficult due to the lack of natural resources of water. Many of these resources are also contaminated by human activities. Many attempts have been made to harvest water from the atmosphere, and condensation systems have received much attention. One of the challenges in generation systems is the high consumption energy of the cooling feed, despite the generation of large amounts of water from the atmosphere. As other airborne contaminants condense with water vapor, the water after harvesting needs to be treated, which adds to construction and maintenance costs. Also, the need for high relative humidity in condensation systems has led scientists to find ways of atmospheric water harvesting at low relative humidity and use renewable energy sources. Sorption systems can absorb atmospheric water without the need for an energy supply and spontaneously. Desiccants such as silica gel and zeolite, due to their high affinity for water, can absorb water vapor in the air through physical or physicochemical bonding, but all of these have slow adsorption kinetics. Therefore, it takes a long time for the water harvesting cycle or they are not able to absorb water at low relative humidity, and others need a lot of energy for the water desorption phase. Metal–Organic Frameworks (MOF) are porous materials that, due to their special structure, are considered the most promising material for atmospheric water harvesting at low relative humidity. MOF-303 has been identified as the most efficient material to date and can harvest 0.7 liters of water per kilogram of MOF-303 at 10% RH and 27 °C. MOFs can harvest atmospheric water even in desert areas using only solar energy, and the water produced is drinkable and does not need to be treated. In this review, systems and methods of atmospheric water harvesting will be studied and compared and then the mechanism of adsorption and desorption in sorption systems will be discussed in detail.

https://pubs.aip.org/aip/pof/article-abstract/36/12/127135/3324420/Air-moisture-harvesting-in-soil-for-indoor?redirectedFrom=fulltext
Physics of Fluids 36, 127135 (2024)
Air moisture harvesting in soil for indoor agriculture: A comparative study of moisture dynamics in shallow porous beds Available to Purchase
Ashish D. Chaudhari, Vijesh V. Joshi

Abstract -- Indoor farming can mitigate water scarcity, declining crop yields, and excessive chemical use in agriculture. However, it demands innovative solutions to reach its full potential. This paper presents a novel indoor plant cultivation technique that leverages atmospheric moisture. Shallow soil bed cooling from below can induce condensation within the soil pores, providing a sustainable water source for plant growth. We tested this method on wheat seed cultivation, observing a 40% growth increase in seedlings with cooled soil beds. We conducted a detailed study of moisture dynamics in porous sand beds to understand the underlying mechanisms of this technique. Choosing sand as a medium isolated the effects of porosity, temperature, and capillary action on moisture condensation. Sand's inertness allows a concentrated analysis of moisture dynamics without interference from chemical reactions or microbial activity. Experiments with cooled sand of varying particle sizes showed moisture condensation levels of 0.025, 0.042, and 0.092 kg/kg for coarse, fine, and superfine sand over 11 days. In soil, moisture reached 0.124 kg/kg over 22 days, highlighting the impact of porosity, temperature, and capillary forces. Our findings reveal exponential moisture increase over time and a linear relationship between bed water content and specific heat. The method is practical and adaptable, especially for remote locations and arid regions, as renewable energy sources can power it. This approach could revolutionize indoor agriculture, particularly in controlled environment systems. Controlling soil temperature can optimize growth conditions, increase yields, and minimize environmental impact. It offers versatility and scalability for various crops and systems.

http://islandsky.com
Skywater

2018 XPRIZE GRAND PRIZE WINNER IN WATER ABUNDANCE!

Skywater Advanced Air-to-Water Technology
The most abundant source of fresh water is the Earth’s atmosphere. When atmospheric humidity condenses, it falls as rain. Skywater replicates this natural process of condensation by simulating the dew point, which allows it to make water continuously, even in low humidity conditions. This is Skywater's patented adiabatic distillation process.

Again replicating nature's process, Skywater generates ozone to purify the water. Ozone (O3), a natural occurring gas that is produced in nature when it rains, binds with water to eliminate bacteria and other impurities. Skywater does this by pumping ozone through the water as it is collected. Unlike other water treatment methods such as chlorine, ozone leaves no taste.

Skywater 250/75
The Worlds finest Atmospheric Water Generator that makes clean, pure, fresh and healthy water. Produces up to 250 Liters of Water a day

https://www.sciencedirect.com/science/article/abs/pii/S0169809516302216
Atmospheric Research, Volume 182, 2016, pp. 156-162
Assessment of atmospheric moisture harvesting by direct cooling
Ben Gido, David M. Broday

Abstract -- The enormous amount of water vapor present in the atmosphere may serve as a potential water resource. An index is proposed for assessing the feasibility and energy requirements of atmospheric moisture harvesting by a direct cooling process. A climate-based analysis of different locations reveals the global potential of this process. We demonstrate that the Moisture Harvesting Index (MHI) can be used for assessing the energy requirements of atmospheric moisture harvesting. The efficiency of atmospheric moisture harvesting is highly weather and climate dependent, with the smallest estimated energy requirement found at the tropical regions of the Philippines (0.23 kW/L). Less favorable locations have much higher energy demands for the operation of an atmospheric moisture harvesting device. In such locations, using the MHI to select the optimal operation time periods (during the day and the year) can reduce the specific energy requirements of the process dramatically. Still, using current technology the energy requirement of atmospheric moisture harvesting by a direct air cooling process is significantly higher than of desalination by reverse osmosis.

https://www.sciencedirect.com/science/article/abs/pii/S0735193322000094
International Communications in Heat and Mass Transfer, Volume 132, 2022, Article 105887
Water production enhancement from the air moisture using nanofluids -- experimental investigation and exergo-enviroeconomic analysis
Masoud Kaveh, Abdollah Khalesi Doust

https://pubmed.ncbi.nlm.nih.gov/30462515/
Langmuir, 2018 Dec 18;34(50):15259-15267.
Efficient Fog Harvesting Based on 1D Copper Wire Inspired by the Plant Pitaya
Lieshuang Zhong, et al.

Abstract -- The leaf of the plant pitaya shows excellent fog harvesting behavior through its 1D thorns with wire-like microstructures. The thorns of it cannot provide enough driving force for the droplet transportation by the special structure and chemistry gradient as the cactus thorns, but it showed efficient water supply which improved the fog harvesting greatly. The mechanism is studied based on 1D copper wire with similar 1D wire-like microstructure and wettability. This structure can significantly reduce the deviation of the fog-laden winds, and the surface intrinsic hydrophility makes water accumulate on it in the form of droplets, which endow it with an efficient water supply that is ∼100 times faster than that on a 2D-flat surface. In addition, it can also enhance the fog capture and water removal. The 3D fog collector composed of 1D microcopper wires has been fabricated which show a high fog harvesting efficiency of ∼13%. This work explains the role of 1D wire-like microstructure in efficient fog harvesting in a different view and provides new insight into the application of developing a more efficient fog collector.

CN115075338 -- Manufacturing and using method of in-fog water collection power generation device

https://pubmed.ncbi.nlm.nih.gov/21381707/
Langmuir, 2011 Apr 5;27(7):3798-802.
Three-dimensional hierarchical structures for fog harvesting
H G Andrews, et al.

Abstract -- Conventional fog-harvesting mechanisms are effectively pseudo-2D surface phenomena in terms of water droplet-plant interactions. In the case of the Cotula fallax plant, a unique hierarchical 3D arrangement formed by its leaves and the fine hairs covering them has been found to underpin the collection and retention of water droplets on the foliage for extended periods of time. The mechanisms of water capture and release as a function of the surface 3D structure and chemistry have been identified. Of particular note is that water is retained throughout the entirety of the plant and held within the foliage itself (rather than in localized regions). Individual plant hairs form matlike structures capable of supporting water droplets; these hairs wrap around water droplets in a 3D fashion to secure them via a fine nanoscale groove structure that prevents them from easily falling to the ground.

https://www.aquatechtrade.com/news/circular-economy/water-generation-atmosperic-air-tech-dive?gad_source=5&gad_campaignid=22788767674&gclid=EAIaIQobChMInsem8MuikAMV9GpHAR3f3xNEEAAYASAAEgI-E_D_BwE
TECH DIVE: Atmospheric Water Generation

https://www.aqualonis.com/
Aqualonis
Floating springs -- Harvesting drinking water with fog nets. Each FogCollector is quick and easy to install while requiring no maintenance. The collectors are carbon-neutral as they are operated without energy. All materials are food-safe. FogCollectors produce high-quality drinking water (approved by WHO standards) and can provide water for agriculture and forestry.

https://www.aqualonis.com/_files/ugd/dd8c81_7dbd962863064dd9819699ac81ce946d.pdf
Aqualonis Price list 2024

https://www.wipo.int/en/web/wipo-magazine/articles/harvesting-fog-to-relieve-water-shortages-in-arid-regions-62982
Harvesting fog to relieve water shortages in arid regions

Videos

https://www.youtube.com/watch?v=LtKXkCfWmyY
Producing drinking water from fog: See how Waterfoundations fog net CloudFisher works // WasserStiftung
The CloudFisher collects drinking water from fog without requiring energy. It is the first standard fog collector in the world resisting to wind speeds of up to 120 km/h. It is quickly installed, does not require additional energy and is extremely low-maintenance. All used materials are food safe.
The german Waterfoundation has spent two years researching and developing the CloudFisher. It can supply hundreds of thousands of people with top-quality drinking water complying with the WHO drinking water standards. It is used around the world in mountain or coastal regions with scarce rainfalls and frequent fog.

https://www.youtube.com/watch?v=0F7CQMd6mQ4
Worlds largest Fog-collector CloudFisher in Morocco – Producing drinking water from fog // WasserStiftung
The video shows the positive effects of the world's largest fog collector system built by the WaterFoundation in Morocco to supply the locals with clean water. The harvesting of clouds and fog has become an increasingly important technology in the worldwide search for new sources of drinking water. For over ten years, the WaterFoundation has been exploring the use of fog-collectors, supporting the work of the Munich industrial designer Peter Trautwein* in developing an entirely new type of collector.
The CloudFisher is the first production fog net capable of withstanding wind speeds of up to 120 kph. It is quickly and easily assembled, consumes no energy and requires very little maintenance. All the materials used are food-safe. The highly efficient CloudFisher system can supply people in many countries with cheap and clean drinking water. The water obtained in this way can also be used in farming and stockbreeding, in reforestation projects or in industry.

https://www.youtube.com/watch?v=5i6Se5oFoWA
Turning vapor into drinking water - Catching fog in response to drought   // DW Documentary
The European Union is funding the "Life Nieblas" project to find out more about the cloud catchers’ potential. In the north of Gran Canaria, researchers have managed to capture tens of thousands of liters of water annually from passing fogs and clouds. The water is being used to reforest a burned-out region on the Canary Island.

https://www.youtube.com/watch?v=YxRONAZoMDk
Desert Fog Nets Catch 10,000 Liters Of Water Daily // Adam Danyal
These fog catchers in the Atacama Desert, Peru, also known as the driest place on earth, capture 10,000 liters of freshwater a day for drinking and growing sustainable food.

https://www.youtube.com/watch?v=THJVuinPbc0
Warka Water towers harvest drinkable water from the air // Dezeen
Italian architect Arturo Vittori explains how his wooden Warka Water structures can provide clean drinking water for rural communities in the developing world.
The tower consists of a bamboo frame supporting a mesh polyester material inside. Rain, fog and dew condenses against the mesh and trickles down a funnel into a reservoir at the base of the structure. A fabric canopy shades the lower sections of the tower to prevent the collected water from evaporating.
"Warka Water is currently represented by a tower that reaches up to the sky to collect moisture from the air and brings it down by gravity to the people," Vittori says.
The performance of the towers varies depending on the weather, but Vittori's aim is to create a structure that would enable the community to extract up to 100 litres of water a day without the reservoir running dry.

https://www.youtube.com/watch?v=Mv6qZAtwKZM
Sahara AWH

https://www.youtube.com/
These 5 innovations will change everything! // Leaf of Life
Since water harvesting is the solution to these problems, we are going to highlight the top 5 water harvesting methods that have been proven to work...

https://www.youtube.com/watch?v=94SbtFgUv34
Water from the air. Homemade atmospheric water generator (AWG) // Mr Yazdan

https://www.youtube.com/watch?v=21H-GOG9zlk
Functional Surfaces A4 - Fog Harvesting (Advanced)
In the last part of this section we looked at the Namib Desert Beetle. In this video we go further and study the Cotula Fallax plant species which has a 3-dimensional water capture mechanism. We also look at the issues faced by current fog harvesting nets and the next generation of biomimetic designs.

https://www.youtube.com/watch?v=iDc6oqz9DEs
From Thin Air [ FogQuest ] // Tony Makepeace
This short video introduces fog collection & FogQuest, a Canadian non-profit organization dedicated to providing clean water solutions in the developing world. Shown in this video are fog collection projects in Nepal, Guatemala and Eritrea.

https://www.youtube.com/watch?v=-6T3ICXWqjc
This water harvester can turn desert air into drinkable water // UC Berkeley
Last October, a University of California, Berkeley, team headed down to the Arizona desert, plopped their newest prototype water harvester into the backyard of a tract home and started sucking water out of the air without any power other than sunlight.
The successful field test of their larger, next-generation harvester proved what the team had predicted earlier in 2017: that the water harvester can extract drinkable water every day/night cycle at very low humidity and at low cost, making it ideal for people living in arid, water-starved areas of the world.

https://www.youtube.com/watch?v=2GRgL4JEL0g
How the aqualonis fog collector works
The video shows the process of collecting the smallest drops of water from fog in specially developed three-dimensional mesh. The aqualonis fog collector is the world's most effective collector for obtaining drinking water from fog.

Atmospheric Humidity Collector Patents

https://worldwide.espacenet.com/advancedSearch?locale=en_EP

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