Categories: Useful Products

Extracting water from thin air and sunshine

With the WaterMaker and a power source, hospital-quality water can be produced from atmospheric moisture, writes Robyn Joubert. With solar energy, it can be available…

With the WaterMaker and a power source, hospital-quality water can be produced from atmospheric moisture, writes Robyn Joubert. With solar energy, it can be available in the middle of the desert, and is currently being used by US troops in Iraq.

A NEW PRODUCT ON THE SOUTH African market literally sucks water out of the air. Using patented technology, US-based AirWater Corporation has developed a range of WaterMaker machines to extract moisture from the atmosphere, filter it, purify it and supply hospital-quality drinkable water.

“The principle is not new – what is new is the way it’s applied,” says local distributor and agent Russell Ellis-Clark. “The moisture in the air is free for the harvesting. The Department of Water Affairs has no jurisdiction on condensation from air, and no environmental impact assessment is necessary. You are not taking water to the detriment of anyone else.

“The WaterMaker has no effect on rainfall patterns. Most of the world is covered with water, and every day the water cycle evaporates billions of tons of moisture from the sea, lakes and rivers, returning it as precipitation. It is impossible to deplete this cycle.”

AirWater Corporation developed its first WaterMaker – a simple, small machine – in 2003. Three years down the line, there are seven models, each with its own capability and applications.

Stand-alone capability
The smallest unit is the SOHO (small office and home solutions), which provides up to 25 litres/day of filtered, drinkable water. It is ideal for homes, providing even higher quality water than bottled water.

Next up is the Commercial (120 litres/day). With a delivery of 250 litres/day, the Worker is designed for the small factory, clinic or workshop. It can be linked to an external water tank to keep it working at full capacity even when its built-in tank is full. It has a hot and cold dispenser and six exit valves to distribute water to multiple users.

The LifeSaver can supply 500 litres/day, a PV solar panel enabling it to operate independently of any other power source. “It can stand alone anywhere,” says Russell. “In drought-stricken areas, it can provide up to 100 people with a very basic ration of 5 litres of water a day – enough to sustain life.

The largest units are the Villager (1000 litres/day), the trailer-mounted Mobile 1 (1000 litres/day), and the Irrigator (5000 litres/day). All units can be run on electricity from either Eskom, oil or gas-fired generators, or solar power.

Perhaps the ultimate WaterMaker is the Sustainer. With a 1000 litres/day or 5000 litres/day unit mounted on a flatbed, it can be moved to any location, parked and left to produce water, the amount of which would depend on relative humidity levels of the air. The Sustainer is designed primarily for defence forces and the SANDF is currently testing them in the Burundi. The American and Israeli defence forces use all the sizes in various applications. It is crucial for the troops in Iraq, enabling them to shower, drink clean water, do their laundry, and cook in the middle of the desert, with water so pure it’s used for batteries.

Tests have shown that water from these units has total dissolved solids (TDS) level of below 14ppm, very low when compared to 130ppm TDS of Durban’s municipal water. Obviously the TDS level of the condensate itself will vary widely according to atmospheric conditions and pollution, and this is why it is treated before being dispensed.

The limiting factor of the WaterMaker technology is its economics – in purchase price as well as price of water produced. Depending on the rand-dollar exchange rate, prices range from R7 500 for the SOHO up to R1,5 million for the Irrigator. With water production per time unit being significantly influenced by air temperature and humidity, and energy consumption being constant, the price per litre will vary correspondingly. At a typical Eskom price of R0,2508/kWh, the 5 000 litres/day Irrigator will cost R542 per day to run, for cost efficiency of at best R0,11/litre. WaterMaker gives the amount of water produced by generator powered units as about 8 litres water per 1 litre diesel at best, 1 litre water per 1 litre diesel at worst. As for solar power, the company gives general figures of /kWh to /kWh installed, with a usable lifespan, depending on conditions on site, of three to 10 years.

Readers can do their own calculations on energy cost based on the purchase price of commercial generators, solar panels and Eskom power. But, at worst, WaterMaker water is still mostly cheaper than bottled water.

The primary use of this technology in agriculture is to produce high-quality domestic water in farm households where its purity and taste makes it preferable to borehole water. Due to the cost, its agricultural production application would currently be limited to hydroponics, and only then if no alternative water is available and/or the crop is of very high value. As the TDS level in WaterMaker water is very low, the water would not have to be tested daily, and nutrients could be added. An interesting application is that of a Zambian farmer who uses a WaterMaker to produce uncontaminated water to inoculate his poultry.

Although WaterMakers work optimally at the coast – the biggest water-maker is the sea and wind – these will produce water from air in almost any conditions. The units are guaranteed for five years.

Contact Auriel Mitchley on (011) 889 0796 or e-mail |fw

How it works
WaterMakers use refrigeration techniques to condense moisture present in the air. A centrifugal fan draws air into the system through an electrostatic filter. A ¬compressor circulates refrigerant through a coil array, the chilled coils condensing moisture from the air. The ¬condensed water drips down and collects in a holding tank underneath the coils. The water is then pumped firstly through a series of high-density and low-density charcoal filters to remove the solids and oxygenate the water, secondly through a reverse osmosis filter and thirdly through an ozone-generating ultraviolet light chamber to kill bacteria. And finally it’s pumped to the holding tank. Depending on the end use of the water, WaterMaker units can be supplied with or without filters and water purification systems.

“Commercial”: technical specs
Production capacity: 120 litres/day
Power supply: 230V, 50Hz, single phase
Input power: 2,6kW
Total power consumption: 0,4kWh/litre

Refrigerant: r407c
Air flow: 1 500m3/h
Optimal working conditions: Temperature 20ºC to 40ºC, relative humidity 35% to 100%
Filtration pump: 110W
UV light chamber: 11W
Electric control: PLC KAV-KOR
Internal water tank: 51 litres
Weight: 140kg
Height: 119cm
Width: 72cm
Depth: 76cm
Machine noise level: 65dB

“Irrigator”: technical specs
Production capacity: 5 000 litres/day
Power supply 400V, 50Hz, three-phase
Input power: 90kW
Total power consumption: 0,4kWh/litre
Refrigerant: r407c
Air flow: 2 200m3/h
Ideal working conditions: Temperature 20ºC to 40ºC, relative humidity 35% to 100%
Internal water tank: 100 litres
Weight: 1 150kg
Height: 180cm
Width: 200cm
Depth: 480cm
Machine noise level: 77dB

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