Participants at this well-attended webinar had lots of questions---too numerous to answer during the Q & A period at the end of the webinar. So the three panelists were asked to reply to a set of questions---the answers were sent recently to the registered attendees. Here are my answers to the set of eight questions assigned to me. They cover a variety of topics. I hope you find the answers interesting and useful.​

• ​What effect will widespread global atmospheric water use have on the world climate?   

The big picture is the water cycle. Every moment, myriad processes, natural and human-caused, are evaporating and condensing huge amounts of water. Liquid water that humans consume for drinking is only temporarily with-held from the water cycle (hours or days). The atmosphere contains 15.5 million million cubic meters of water according to a 1995 report by the American Geophysical Union. Various natural processes already transport and distribute vast volumes of water vapor and liquid water across Earth. Even if every single human alive in 2050 (using the UN's 2007 projection for a population peak of 9,200 million people) used water from water-from-air machines at the rate of 50 L (0.050 cubic meters) per day, they would consume (temporarily) only 0.003% of the available atmospheric water. This scenario involving the entire human population is unlikely, so it is also unlikely that water-from-air technologies will cause a drier atmosphere in the context of the Earth’s water cycle and natural processes of water transport and distribution.

Water vapor, the gas phase of water, diffuses along pressure gradients to zones of lower water vapor pressure. If a lot of water vapor was condensed into liquid water in a specific region such as a city, water vapor from outside the region would flow in immediately. No net loss of atmospheric water vapor density would be observed in the city.

Water consumed for domestic water requirements does not exit from the water cycle. Within a day or so the liquid water that is used or temporarily with-held from the water cycle would be returned to the environment by evaporating into atmospheric water vapor.

On a clearly bounded terrestrial surface such as a tropical island, atmospheric water vapor processing systems would increase slightly the annual precipitation. Let us say a large-scale AWG array is installed on an island such as Grand Turk (Turks & Caicos Islands). The island has a surface area of 18 square kilometers (1,800 ha). The AWG array produces water from the air at a rate of 75,335 cubic meters annually. This is equivalent to a rainfall of 7,533 mm over one hectare (10,000 square meters). The average annual precipitation of Grand Turk is 604 mm. This value would be enhanced by [7,533 mm/ha/1,800 ha] = 4 mm (or 0.7% annually, an amount less than the natural variability from year to year. The annual total precipitation in the year 2000, for example, was 704 mm.  

To reinforce the fact that long-term human direct impact on atmospheric water is negligible, note that dehumidifiers and air-conditioners dripping condensate have been increasingly used since the 1950s. I used NOAA global specific humidity data (measured in grams of water per kilogram of air) and subtracted the earlier 30-year 1951 to 1980 annual field from the  more recent 39-year 1981 to 2019 field. The resulting map showed several pools of higher specific humidity (+2 g/kg). These are likely related to climate change. Drying of about -2 g/kg is noticeable over the Sahara and Gobi deserts---more likely to be related to climate change than use of HVAC equipment. Over most of Earth specific humidity has been remarkably stable (+/-1 g/kg) for the past seven decades. By the way, I posted the map in the Atmoswater Research blog. Indirect environmental impacts are more likely. These will be related to the materials used in manufacturing AWGs, product life cycle aspects, and so on. Also, AWGs will enable humans to expand their footprint which could increase population density in a region, lead to increased sewage and waste disposal challenges, and increase energy use. 

These analyses indicate widespread global atmospheric water use will not noticeably affect the world climate.

• How does the cost of atmospheric water compare for a drinking water source as compared to more conventional sources?

In a tropical climate where a chilled-coil AWG produces water at its rated capacity every hour of the year the electrical energy cost of the water will be, on average, about 0.4 kWh per liter (400 kWh per cubic meter; 1.5 kWh per US gal).

More conventional sources of water have these electrical energy costs:
- Surface water, public supply: 0.37 kWh/cubic meter (Young, 2014)
- Groundwater, public supply: 0.48 kWh/cubic meter (Young, 2014)
- Tap water, 0.46 kWh/cubic meter (Gleick & Cooley, 2009)
- Municipal water (S California): 3 kWh/cubic meter (Gleick & Cooley, 2009)
- Seawater Desalination (reverse osmosis): 2.5 to 7 kWh/cubic meter (Gleick & Cooley, 2009)
- Seawater Desalination (reverse osmosis): 2 kWh/cubic meter (Elimelech & Phillip, 2011, p. S1)
- Bottled Water: 519 to 945 kWh/cubic meter [Gleick & Cooley, 2009; thermal energy units were converted to electrical energy units (3:1) to derive these values]

It was interesting to discover that AWGs used in tropical climates are competitive with bottled water. Keep in mind the apparently cheaper conventional sources may not even be available in some water scarce regions. The desalination costs do not include the apparently difficult to monetize costs of harming local ecosystems with brine disposal.

References:
Elimelch, M. & Phillip, W. A. (2011) Supporting Online Material for The Future of Seawater Desalination: Energy, Technology, and the Environment. Science 333, 712-717.
Gleick, P. H. & Cooley, H. S. (2009). Energy implications of bottled water. Environ. Res. Lett. 4 (2009) 014009 (6pp).
Young, R. (2014). Watts in a Drop of Water: Savings at the Water-Energy Nexus. An American Council for an Energy-Efficient Economy (ACEEE) White Paper. Retrieved from https://www.aceee.org/sites/default/files/watts-in-drops.pdf 

• Is there any air cleaning value to AWG? 

If the air entering the machine is strictly indoor air, the air filter in the machine may clean the air slightly but AWGs from credible suppliers are not intended to be air cleaners.

• COST: Do you have a unit cost for AWG on a per gallon basis?

From a typical retail price list, these are the USD unit costs per US gal of water production capacity when the air temperature is 85 F and the relative humidity is 75%:
- AWG rated for 5 gal/day: $300/gal (residential quality)
- AWG rated for 10 gal/day: $420/gal (balance of list is commercial/industrial quality)
- AWG rated for 40 gal/day: $178/gal
- AWG rated for 140 gal/day: $121/gal
- AWG rated for 800 gal/day: $98/gal
- AWG rated for 1800 gal/day: $82/gal

• What is the lifetime for the equipment?

Comparable equipment is used in air-conditioning. Typical equipment lifetimes range from 10 to 20 years given proper maintenance.

• What is the lifetime for an ultraviolet lamp?

12 months. The lamp must be changed annually even if it appears to be still working because the output may have decreased below the threshold for reliable inactivation of microbes.

• Over the 35 years you’ve been studying this sector, there has been a trail of broken dreams with few companies gaining long-term traction. How has the increased prevalence of these systems and recent funding news (like the $50M to Zero Mass Water [now called SOURCE Global]) changed the conversations you’re having? And, from what sectors or geographies are you hearing the greatest interest?

Conversations have not really changed. We are still firmly in the early to late majority phase (this terminology is from a 2018 article by Paul O’Callaghan and others). This stage lasts typically 12 to 16 years. I think this stage started about 2010. So, increased prevalence of systems and the SOURCE Global funding news are just part of this stage of the AWG industry. Sectors and geographies: Oddly, just in the past few days I have seen two references to US Military interest in AWGs. Otherwise, the drinking water supply sector in the United Arab Emirates is a bit of a hot spot for interest this year.
​

• Mojave Desert nighttime humidity is as high as 50% and daytime is much lower. It would seem as though the richest source of water is at night when the availability of sunlight is least. It would seem battery use is critical. How many kilowatts is required per 1000 gallons of water?

For air with a given water vapor content, the relative humidity value increases when temperature decreases (such as at night) and the relative humidity value decreases when temperature increases (with solar heating during the daytime). Water vapor content (the atmospheric water resource) actually is quite stable from day to night to next day being related to the properties of the air mass enveloping a region.  Modeling a chilled-coil AWG operating in the climate of Las Vegas shows that water production would be unreliable year-round with this type of machine. Therefore, a desiccant AWG should be considered. An AWG having a rotary solid-desiccant dehumidifier would produce water year-round (usually reasonably close to its water production specifications) according to an ASHRAE model. For an off-grid desiccant AWG, having battery power available during the night increases productivity of the system because the atmospheric water capture process can continue 24 hours per day. An off-grid desiccant AWG could use a solar thermal process during daylight hours to heat the desiccant to release water vapor for subsequent condensation into liquid water. Desiccant AWGs can also use an electric heater to reactivate the desiccant.

The energy cost of water produced by a desiccant AWG was estimated two ways (note that kilowatt is a unit of power---the energy unit is kilowatt x hours, kWh, which is power acting over a period of time):

a. Specifications for a line of industrial rotary desiccant dehumidifiers (using electrical energy) manufactured by Hangzhou Peritech Dehumidifying Equipment Co., Ltd. (http://www.desiccantwheeldehumidifier.com/sale-2082217-industrial-rotary-desiccant-dehumidifier-silica-gel-economical-dehumidifier.html). Their 14.4 L/day model produces water using 2.8 kWh/L (10.6 kWh/US gal or 10,600 kWh per 1000 US gal). Their 1,102 L/day model produces water using 1.3 kWh/L (4.9 kWh/US gal or 4,900 kWh per 1000 US gal).

b. Using information in the SOURCE Global (formerly Zero Mass Water) Patent Application US 2018/0043295 A1. The document includes an example of operation in Amman, Jordan at 14:00 on a July day. Airflow is 90 cfm. Relative humidity is 30%. A solar thermal panel with surface area 1.5 square meters provides 700 W (at 50% efficiency) to heat the desiccant to release captured water at the rate of 0.3 L/h. This information can be interpreted three different ways because international consensus is lacking on comparing different energy sources (e.g., solar thermal versus electricity; read more at the American Physical Society Site https://www.aps.org/policy/reports/popa-reports/energy/units.cfm). We need to make this comparison because the Peritech dehumidifiers and all chilled-coil AWGs are energized by electricity.
i. Thermal energy = electrical energy cost of water = (700 W x 1 h)/0.3 L = 2.33 kWh/L; efficiency of solar thermal assumed to be 100% as per OECD/IEA publication guidelines
ii. Equivalent electrical energy cost = 0.76 kWh/L; efficiency of solar thermal assumed to be 33% as per DOE/EIA (USA) publication guidelines
iii. Equivalent electrical energy cost = 1.17 kWh/L; efficiency of solar thermal assumed to be 50% as stated in the patent application

The range of energy costs for the SOURCE Global patent application example is 2.8 kWh/US gal (2,800 kWh per 1000 US gal) to 8.7 kWh/US gal (8,700 kWh per 1000 US gal).

Here are some product design notes applicable to atmospheric water generator products. The notes are based on an interview with Mitch Maiman, Intelligent Product Solutions by William G. Wong of Electronic Design magazine (July 26, 2020).

Essential elements

• Objective market assessment (problem being solved for user, understanding of criteria inducing customer to buy)
• Define product requirements (features, functions, cost, and volumes)
• End product must deliver on a business opportunity

Common design mistakes to avoid

• Development activities lose sight of product requirements causing project to go off course and miss deadlines
• Over-designing for the application (increases cost, weight)---scheduling problems result
• Misunderstanding cost, time, and expertise required for the product design process
• Not enough reliability testing of the new product

Best process

• Tailor the design process to the project complexity, regulatory needs, and risk profile of the client

Embrace smart products

• Incorporate sensors, processing, and wireless communications (but avoid over-design)
• Smart product design usually needs a team with a wide range of expertise---mechanical, electrical, radio-frequency, embedded systems, and application software.

This is an interesting article about the drinking-water-from-air industry. It also includes a section on fog harvesting. Atmoswater Research got a nice mention!

This article is a good overview of the COVID-19 virus in relation to systems processing drinking water and wastewater. Water-from-air machines (atmospheric water generators, AWGs) are, of course, small-scale drinking water systems. Even though the drinking water within the system may be safe, spigot handles and machine surfaces could be contaminated by viruses and bacteria. Machine users should wash their hands before operating the machine. Machine surfaces, spigots, and spigot handles should be sanitized frequently.

For the air-side of water-from-air systems, relevant information is provided at ASHRAE Resources Available to Address COVID-19 Concerns. 

For the water-side of water-from-air systems there are two good sources of information:

1. The World Health Organization (WHO) Technical Brief titled, Water, sanitation, hygiene and waste management for COVID-19. 
2. Water Quality Association Coronavirus (COVID-19) Update 

The Water-from-Air Industry is actively growing! This chart is from the data table below tabulating the founding years for Water-from-Air companies [suppliers of Atmospheric Water Generators (AWGs)]. Companies that failed between 1990 and the present are not included. Only those companies with active websites as of today are included. Founding year information is from the company websites or the LinkedIn profiles of the companies or their founders. The two pre-1990 companies were not set up initially as water-from-air equipment suppliers. Companies started in the 2016–2017 peak years were not apparently a direct response to the Water Abundance XPrize competition which ran during 2016–2018. Founding years were not available for 11 of the 73 companies listed below. The last 10 years saw the formation of 37 firms—half of the existing companies. There has been no apparent merger and acquisition activity. Dozens of companies are marketing actively their AWGs. At least two or three dozen units are operating worldwide (see Case Studies page). According to O'Callaghan and others (2018) when "at least 3 companies actively offer versions of the technology; [with] more than 12 full-scale units in operation" this is one signal the industry is in the "Early and Late Majority" stage which can typically last 12 to 16 years. Two other signals stated by O'Callaghan and colleagues are that "Consulting engineers now specify the technology..." and "Efficiencies [are] gained in engineering design and process optimization." 

Reference: O'Callaghan, P. and others (2018). Development and Application of a Model to Study Water Technology Adoption. Water Environment Research, June 2018, 563–574.

pre-1990 (2)

• Francopost Srl, Italy (1961)
• Yildiz Makina Sanayi Ltd., Turkey (1983)

1991
1992 (1)

• Yueqing Kemao Electric Co., Ltd, China

1993
1994
1995
1996
1997 (2)

• Atmoswater Research
• Excel Water Technology, Inc., Virginia, USA

1998 (2)

• Shenzhen FND Air & Water Technology Development Co., Ltd., China
• Water Technologies International, Inc., Florida, USA 

1999
2000
2001 (2)

• Hendrx, China
• MSP Technology.com, LLC, Kentucky, USA

2002 (1)

• Island Sky Corporation, Florida, USA

2003 (4)

• Air2Water LLC, California, USA
• Aqua Sciences, Inc., Florida, USA
• Atlantis Solar and Wind LLC, California, USA
• Canadian Dew Technologies Inc., British Columbia, Canada​ 

2004 (4)

• Aquaer Generators S.L., Spain
• Global Site Solutions Inc., British Columbia, Canada
• Ray Agua Universal, Spain
• WaterMaker (India) Pvt. Ltd., India

2005
2006 (2)

• Air Solar Water & Rain Capture, Washington, USA
• Air Water™, South Africa 

2007 (1)

• EuroSport Active World Corp (EAWC) Technologies, Florida, USA

2008 (3)

• Genaq Technologies S. L., Spain
• Quest Water Solutions, Inc,, British Columbia, Canada
• Rainmaker Worldwide Inc., Ontario, Canada

2009 (1)

• Veragon Srl, Italy

2010 (4)

• AT Company, Korea
• AtmoWater Inc. (Ser-Manukyan Family Holdings), USA
• DewPoint Systems, Hawaii, USA
• ​SEAS SA, Switzerland
• Water-gen LTD, Israel

2011 (2)

• Atmospheric Water Solutions, Florida, USA
• Infinite Water, Inc., New York, USA

2012 (3)

• Drinkable Air, Inc., Florida, USA​
• SunToWater Technologies, LLC, Texas, USA
• World Environmental Solutions Pty Limited, Australia

2013 (2)

• Aquavolve, LLC, Massachusetts, USA
• Vitality Vector, BV, Netherlands​

2014 (4)

• Atmospheric Water Generator, LLC (Quench Innovations), Florida, USA
• AWG Contracting, LLC, Texas, USA
• Skywell Solutions Ltd (Requench), UK
• Zero Mass Water, Inc., Arizona, USA

2015 (4)

• FreshWater Solutions, Chile
• PanLbilt Global, Illinois, USA
• Water From Air, South Africa
• Water Generating Systems, LLC, Washington, DC, USA

2016 (6)

• Akash Ganga (Clean Water Generator Pvt. Ltd.), India
• Amigoz Innovative Technologies Pvt. Ltd (Aguaer), India
• Aquacello, South Africa
• Generation Water Company Limited, Singapore
• Maithri Aquatech Pvt Limited, India
• Skysource.org, California, USA

2017 (8)

• Akvo Atmospheric Water Systems Pvt. Ltd., India
• Drupps AB, Sweden
• Jordan's Air 2 Water, Minnesota, USA​​
• Majik Water, Kenya
• Talisa Water, South Africa
• Tsunami Products, Inc., Washington, USA
• Uravu Labs, India
• Watergen USA, Florida, USA

2018 (2)

• Innovative Teknologies, India
• LiquidSky, India

2019 (1)

• Agua de Sol, France

Unknown year (11)

• Aid Water Global, LLC, Texas, USA
• Air 2 Water Solutions, California, USA
• Air-O-Water, India
• Airwaterex Ltd, Cyprus​
• Ardor Marketing Pte Ltd, Singapore
• AW International Ltd, Puerto Rico
• GOODWATER Beteiligungs GmbH, Austria
• Proficient Machine and Automation, Michigan, USA
• RainInABox.org (Rocillo Innovative Technologies, Inc.), California, USA
• Skywell, LLC, California, USA
• Water World Solution, France

This YouTube video by the Dutch foundation, Happy With Water Foundation, reviews several atmospheric water vapour processing methods and then states that an absorption cooling method using solar energy and vacuum tubes with heat pipes reduces the energy cost of water making it relatively more affordable and practical compared to most other options.

In response to a reader's comments, the July 2018 reprinted second edition incorporates enhanced temperature versus relative humidity psychrometric tables in Chapter 4 with wider temperature ranges (0–55 °C; 32–132 °F) for finding water vapour density, humidity ratio, and dew-point. This makes the tables more useful for cities like Abu Dhabi, Doha, and Dubai.

This reprint also has a revised Appendix 6: Economics of Off-grid Solar PV for WFA. There are two detailed examples in the Appendix. The first example is for a 1.05 kW input power atmospheric water generator using 1-phase electric power. The second example is for a 2.1 kW input power atmospheric water generator using 3-phase electric power.The Appendix presents clear diagrams showing the main components of single-phase and three-phase off-grid solar PV systems. The Appendix concludes by revealing, for each example, the ratio comparing the price of an off-grid solar PV system to the price of the atmospheric water generator.

The Water-from-Air Quick Guide may be purchased from Amazon. 

​Thermoelectric cooling technology has had wide appeal as an alternative to mechanical refrigeration cooling technology for at least twenty years. Thermoelectric systems avoid the use of hazardous, harmful refrigerants and noisy compressors​. Low coefficient of performance (COP, in the range of 0.9–1.2) is the main problem preventing widespread use of thermoelectric cooling especially for systems requiring large cooling capacities (Riffat & Ma, 2004). A COP of 1.2151, achieved using a multistage thermoelectric module, was considered "remarkable" by Patel and others (2016)  Only smaller capacity niche applications have been commercialized.

There have been several peer-reviewed papers published and patents issued for atmospheric water generators or dehumidifiers using thermoelectric cooling devices which use the Peltier effect. Some information and products have been featured on websites. Each reference below represents a clickable link to more information.

Examples of papers

Atta, R. M. (2011). Solar Water Condensation Using Thermoelectric Coolers. International Journal of Water Resources and Arid Environments, 1(2), 142–145.

Milani, D., Abbas, A., Vassallo, A., Chiesa, M., & Bakri, D. A. (2011). Evaluation of using thermoelectric coolers in a dehumidification system to generate freshwater from ambient air. Chemical Engineering Science 66(12), 2491-2501.

Muñoz-Garcia, M. A., Moreda, G. P., Raga-Arroyo, M. P., and Marin-González, O. (2013). Water harvesting for young trees using Peltier modules powered by photovoltaic solar energy. Computers and Electronics in Agriculture 93, 60–67.

Nandy, A., Saha, S., Ganguly, S. & Chattopadhyay, S. (2014). A Project on Atmospheric Water Generator with the Concept of Peltier Effect. International Journal of Advanced Computer Research, 4, 481–486.

Suryaningsih, S. & Nurhilal, O. (2016). Optimal design of an atmospheric water generator (AWG) based on thermo-electric cooler (TEC) for drought in rural area. AIP Conference Proceedings 1712, 030009 (2016); doi: 10.1063/1.4941874

Davidson, K. B., Asiabanpour, B., & Almusaied, Z. (2017). Applying Biomimetic Principles to Thermoelectric Cooling Devices for Water Collection. Environment and Natural Resources Research 7(3), 27–35.

Examples of Patents

Peeters, J. P. and Berkbigler, L. W. 1997. Electronic household plant watering device. United States Patent 5,634,342. [expired, now in public domain]

Wold, K. F. 1997. Plant watering device and method for promoting plant growth. United States Patent 5,601,236. [expired, now in public domain]

Reidy, J. J. 2008. Thermoelectric, High Efficiency, Water Generating Device. United States Patent 7,337,615.

​Waite, R. K. & Neumann, A. (2017). Water production, filtration, and dispensing system. United States Patent 9,731,218 B2.

​
Examples of Websites

The "instructables" website published the article "How to Make a Dehumidifier (Thermoelectric Cooling) in 2016.

Amazon.com sells several models of "thermoelectric portable compact dehumidifiers".
​
​References

Patel, J., Patel, M., Patel, J., & Modi, H. (2016) Improvement in the COP of Thermoelectric Cooler. International Journal of Scientific & Technology Research 5(5), 73–76.
​
Riffat, S. B. & Ma, X. (2004) Improving the coefficient of performance of thermoelectric cooling systems: a review. Int. J. Energy Res. 28: 753-768 (DOI:10.1002/er.991)

The target market for atmospheric water generators, in the broadest sense, are people in locations with perennial water shortages due to population growth, climate change, and lack of enough sustainable surface or groundwater within a radius of 100 km. The reference for these defining conditions is: Lalasz, R. (2011). New Study: Billions of City Dwellers in Water Shortage by 2050; retrieved from https://blog.nature.org/conservancy/2011/03/28/pnas-billions-city-urban-water-shortage-2050-nature-conservancy/. A study led by the Nature Conservancy defined these conditions. At least 23 cities fit these conditions. From north to south they are: Shenyang, Beijing, Tehran, Haifa, Tel Aviv, Jerusalem, Lahore, Delhi, Dubai, Riyadh, Abu Dhabi, Kolkata, Mexico City, Mumbai, Hyderabad, Manila, Chennai, Bengaluru, Caracas, Lagos, Cotonou, Abidjan, and Johannesburg. Some small tropical islands such as Grand Turk, Turks and Caicos Islands and Sal Island, Cabo Verde also fit these defining conditions. Recent reports such as “The 11 cities most likely to run out of drinking water - like Cape Town” by the BBC (http://www.bbc.com/news/world-42982959; 11 February 2018) suggest that we could add other cities to the Nature Conservancy’s list. From the BBC report here are nine more cities to add to the list of those likely to run out of sustainable natural water supplies: Cape Town, São Paulo, Cairo, Jakarta, Moscow, Istanbul, London, Tokyo, and Miami.Water-from-Air Resource Charts are available for all the highlighted locations mentioned in this post—just click on the location name to go to the relevant page in the Atmoswater Shop. By the way, if you like bargains, the charts for the 23 water-scarce cities listed by the Nature Conservancy are all included in the book, Water-from-Air Quick Guide.

Tour Stop 8: In San Francisco, the diurnal regime of the water-from-air resource is somewhat variable with the seasons. (Click on images to enlarge them)

Abstract from my article published February 11, 2014 on Water Online:

Quantifying the water-from-air resource enables targeting selected cities where installing strategically located stand-alone processors of atmospheric water vapor will have the quickest, most beneficial impact for people facing water scarcities.

While helping a client commercialize water-from-air systems, I got frequent questions about how well atmospheric water generators would perform at various locations around the world. A common misconception was that relative humidity values told the whole story. Higher humidity means more water in the air and better water production. Right? Not really!

The water vapour content of the air, sometimes referred to as "absolute humidity", has the proper scientific name "water vapour density" with units of [grams of water vapour per cubic metre of air]. The water vapour density depends on three measures all at the same time: the air's dry bulb temperature, relative humidity, and atmospheric pressure.

Monthly average climate data for air temperature (dry bulb) and relative humidity is fairly easy to obtain for many places. Average air pressure at a location can be estimated knowing the site's altitude above sea level. Using well-known formulas used in the heating, ventilation, air-conditioning field (HVAC) the average monthly water vapour density can be calculated.

Once water vapour density was known, I could use information about the airflow (in units of cfm or cubic feet per minute) through my client's machines to estimate water production of various designs. The focus on water production was fine for a manufacturer and its customers.

Later, as an independent consultant, potentially dealing with end-users of atmospheric water generators having all sorts of different specifications for airflow I decided it was better to focus on the actual water vapour resource to make charts of wider usefulness.To make it easier to compare how good a site is for atmospheric water generators I had the idea of indexing the water vapour density by dividing the density values by the water vapour density 15.3 g/cubic metre which is the density at the standard measurement conditions of 26.7°C air temperature; 60 % relative humidity. When the water-from-air resource monthly index = 1.00, the expected drinking water production rate from an atmospheric water generator (AWG) at the site should be the same as the machine's specified water-from-air production rate. I gave the Water-from-Air Resource (WFAR) annual index grades (Excellent: Index is greater than or equal to 1.00; Good: Index range 0.76 to 0.99; Fair: Index range 0.51 to 0.75; and Poor: Index range is less than or equal to 0.5) and assigned colours to make it easier to interpret the charts.

A lot of information about a site, all relevant to using water-from-air systems is packaged onto the 8.5 inch x 11 inch landscape format of the charts!

• Geographic coordinates and elevation;
• Monthly average temperature, humidity, pressure, and dew-point;
• Monthly average water vapour density;
• Monthly average maximum mechanical dehumidification efficiency;
• Graph to visualize how temperature, humidity, dew-point, and efficiency vary together by month;
• Graph to visualize and compare monthly average water vapour density with water vapour density at standard conditions;
• Summary of the analysis, identifying the climate zone and expected atmospheric water generator performance for various periods during a year; and
  
• Annual index to compare the water-from-air resource between locations

After a bit of experience using the charts my clients discover some of their business stress evaporates! Here's why:

• They don't have to spend their own time and resources responding to ongoing questions about how good or bad a place is for operating water-from-air systems. This gives just a bit extra time for concentrating on growing their business and profits;
• Risk reduction by understanding the characteristics of the water-from-air resource at a site. Why alienate their customer by selling them a machine that might only work properly a couple of months of the year at a site? Better to forgo that sale and focus on sites where the machine return on investment is more favourable;
• The charts make their business more valuable—they become more of an expert at what they do;
• They find it easier to achieve sales targets because quantitative information, rather than a guesstimate is available; and
  
• Surprises are removed with having solid quantitative knowledge about the water-from-air resource at sites.
  

Today, I have a guest post from Walter Wallie Ivison, Director and CEO of World Environmental Solutions, Australia. As usual, Atmoswater Research is not responsible for the contents of external links.

Water-from-Air Trends is a new feature on the Atmoswater Research website. Courtesy of Google, it is possible to follow interest trends for various search terms. The charts are embedded so are right up-to-date. The trend information is useful for developing marketing strategies. Here is a snapshot of the 12-month trend for the phrase, "water from air".