Atmoswater™ Research

• Question. Do minerals need to be added to drinking-water-from-air?

           
Answer. "No. The human body gains the minerals necessary to good health primarily through eating foods, not through drinking water. The body may absorb or use the minerals in water but, in most cases, the amount would not be significant. In order for a person to obtain sufficient minerals from water, it would be necessary to drink many gallons daily. In general, neither a water with a high mineral content, nor a fully softened water, could be considered a significant source of minerals. In contrast, one glass of milk provides the mineral equivalent of multiple gallons of ordinary well water.

                Note: Certain trace elements, such as fluoride, iodine, etc., may be obtained from water."

            (from Water Quality Association, International Headquarters and Laboratory, Lisle, Illinois, USA)

• How do I compare the effectiveness of competing methods of obtaining water from the air?

Comparisons are possible if the equipment provider has stated water production capacity and energy input of their device at the standard conditions of 26.7 degrees C (80 degrees F) and 60% relative humidity. These are the standard conditions used by the dehumidification industry. The reference publication is AHAM DH-1-2008, Dehumidifiers, by the Association of Home Appliance Manufacturers.

• Would the quality and quantity of water produced from air change depending on air quality (pollution index)?

Water quality is affected by air quality. For example, while operating a water-from-air machine in a region of eastern Canada, where electricity is produced by coal-fired plants, water quality tests revealed a trace of strontium in the product water of the machine. Although we did not test the air, we surmised the ambient air contained traces of strontium from combustion of coal. Strontium was not detected in product water while testing several machines in western Canada where electricity is from hydro-electric sources. Volatile organic compounds (VOCs) in the entering air can also pass through the system into the product water unless one or more VOC filters are added to the water flow path. Particulates in the ambient air can be removed by air filters before the air enters the water-from-air processing system. Sediment filters can be inserted into the water flow path to remove fine particulates not removed by the air filter. Before starting long-term use of water-from-air product water at a site, it is wise to have a sample of the product water tested by a reputable laboratory to ensure the water quality meets national or World Health Organization water quality guidelines. Tests should be scheduled annually to verify that water quality remains acceptable.

• Would the quantity of water produced vary on a day to day basis?

Yes, water production rate depends on the water vapour density ("absolute humidity") of the ambient air. The water vapour density changes according to weather conditions related to characteristics of the air masses passing through the region in which the water-from-air machine is located. Day-to-day variability is minor usually but month-to-month and seasonal variability can be substantial, especially in temperate climates.

• Given the fact that water quality is affected by air quality, how then would one market this product in a third world country? Would any one manufacturer need to do air quality analyses in each interested market (country) before soliciting its business? Thank you. A concerned distributor.

The manufacturer and its distributors should be aware of air quality conditions in each market area. Air quality could be different in the same city. The city's suburbs are likely to have better air quality than its industrial areas. Alternatively, prevailing winds may keep industrial or zones with heavy vehicle traffic relatively unpolluted while suburbs downwind are enveloped in polluted air. Ultimately,it is more effective to test water quality than air quality—it is the end result that counts. A responsible distributor of water-from-air machines (perhaps sharing costs with the manufacturer) should do an annual test of the water from at least one representative machine from each "air-shed" of their market area. This comprehensive test should include inorganic parameters, organic parameters, and physical parameters. Testing should also be done for microbials. If nuclear power plants are nearby, it would be wise for the testing to include radiological parameters. Althought this type of water testing is expensive, a proportion could be factored into  the selling price of the machines at both the manufacturer's and distributor's levels, or into maintenance contracts, so that there is no financial-based excuse for not performing the annual tests. The end-users should not be expected to do the testing. The manufacturer and distributor must bear the responsibility as part of their role as water-from-air technology providers in their region. If problems with the water quality are found, the end-users must be notified immediately. Therefore, best efforts must be made to maintain up-to-date lists of machine owners—just as automobile dealers and manufacturers keep track of customers in case there has to be a recall for defective vehicles. Specific filters, such as for volatile organic compounds (VOCs) may have to be added to machines in some market areas. Although all this may come across as discouraging, keep in mind that many regions where water-from-air machines are practical are likely to have relatively clean air. The increasing need to use water-from-air machines is yet another reason for all people to treat our "atmospheric-commons" with respect and not use the atmosphere as a dumping place for waste products of our activities.

• How much energy is used to produce a liter of water in optimal conditions?

First let us say that optimal conditions = standard test conditions for dehumidifiers which is 26.7 C dry bulb air temperature, relative humidity 60%, and air pressure at one atmosphere. Under these test conditions, I have found both through modeling and real world measurement experience that 20 L/day machines consume 0.68 kWh per litre of water produced. Larger machines, typically rated at 2500 L/day consume 0.4 kWh per litre of product water. This is because the larger machines are more efficient at using the atmosphere as a heat sink. It is interesting to note that in natural systems, the energy consumed to change the phase of water from gas to liquid (enthalpy of vaporization, formery called 'latent heat') is 0.681 kWh per litre.

• Is there a solar pv component to provide energy to the WFA device?

At this time, the cost of solar PV systems remains too high to be feasible to use with water-from-air systems. Sufficient battery storage must be part of the system to allow 24 hour operation. Every hour of operation is precious because of the relatively low rate at which water-from-air systems process water vapour into liquid water.

• Are these products/devices currently being produced and distributed?

Several manufacturers are producing and distributing water-from-air systems at various scales. I have begun to compile a list of links to manufacturers posted at http://www.atmoswater.com/provider-links.html. Caveat emptor. My company, Canadian Dew Technologies Inc. (www.candew.ca) is set up to design and build custom systems at scales larger than 1000 L/day on a project basis.

Water pseudo-science: Curious about terminology used at some water-from-air system provider's websites like "Pi Water", "Alkaline Water", and so on? Visit the excellent website by retired chemistry professor Stephen Lower (Vancouver, Canada).