The City Dehumidified

I’m in London, watching snowflakes fall amidst early morning rain flurries, reading David Grann’s new book The Lost City of Z, and getting ready for the Barbican event tomorrow night.
But there’s an article in the Guardian today about the WaterMill, which “uses the electricity of about three light bulbs to condense moisture from the air and purify it into clean drinking water.” The company, Element Four, imagines a future for their product involving everything from irrigation and personal thirst to peacekeeping and disaster relief. Perhaps it might even require an update to the atlas of hidden water – where the water supply is “hidden” in the sky itself.

[Image: A diagram of the WaterMill at work].

As the company describes it:

The system draws in moist, outside air through an air filter. The moist air passes over a cooling element, condensing the moist air into water droplets. This water is then collected, passed through a specialized carbon filter and is then exposed to an ultraviolet sterilizer, eliminating bacteria.


The WaterMill is installed unobtrusively on the outside of your home, using outside air, so it won’t dry out the air you breathe in your home. And don’t worry if your outdoor air is less than pristine – even if you live in a crowded city, the Watermill’s filtration system ensures your drinking water will be clean and free of toxins and bacteria – more pure than tap water or even spring water.

You’re basically drinking water from a dehumidifier, then.
According to the Guardian, the obvious – if extremely uninteresting – next question is: “are you crazy?” But it would seem that the next question might actually be one of large-scale climate-engineering and the future of urban design.
In other words, would it be possible to re-engineer a city’s weather patterns through the judicious and geographically strategic deployment of WaterMills? What might happen if this were to occur accidentally, over time, and according to no particular plan?
Over the years, say, tens of thousands – even millions – of these machines are installed in a humid city like New York, Tokyo, or London, achieving imperceptibly slow local climate modification. The city goes into a drought, with very little rainfall as humidity disappears – and it’s all because of a certain line of products that have been installed, gradually, home by home, over the course of a decade.
Sucking hundreds of thousands of liters of water out of the air everyday, and re-directing that water into the sewage system through the metabolic processes of human bodies, these machines inadvertently re-engineer the local climate.
I remember walking to a restaurant through almost unbelievable summer humidity, thinking that massive, solar-powered air-conditioning units installed atop Manhattan skyscrapers could flood the surrounding streets with downward winds of cooled air to avoid uncomfortable nights – but industrial-sized WaterMills might accomplish the same thing, sitting up there in the heights of the marvelous, stealing water from the sky. Anti-clouds. Black engines atop roofs prevent rainfall. Whole summer storms could be stopped before they form. City-wide, temperatures drop and the humidity falters.
The resulting fresh water is then sold to Spain.
So if designer climates are the future of urban design, something explored in the forthcoming BLDGBLOG Book, then perhaps the widespread use of WaterMill technology might be an interesting way to start. Convince enough people in one large building, say, or even one borough, to install a home WaterMill… and see if the local climate begins to change.

23 thoughts on “The City Dehumidified”

  1. London’s climate was similarly accidentally modified in the 18th to 19th centuries as increasing numbers of coal fires meant suspended particles hung in the damp air, producing the famous pea-souper fogs. Since the clean air act was passed in the 1950s, banning coal and wood fires, the skies are clear – well, for London.

  2. Currently I am in my third year of study (Landscape architecture).My dissertation will be exploring the disconnection of man and nature through Landscape Architecture and Architecture.Will we continue on our current path of a highly networked, yet disconnected world as our humanity seemingly dissolves into the digital age? If we take a look at the present then, my gut feelings tell me that landscapes cinematic in scope and feeling, will be our Future…exploring the past…’ Civilisation the knowledge and capacity that man has acqiured to control the forces of nature and extract its wealth for the satisfaction of human needs’ (Sigmund Freud, The future of illusion). Freud explains that man s only fear is nature. Civilisation and its foundations were to protect one selves from nature. Nature gives us life then takes it, cold and relentlessly, so man tries to control because of his fear…this gives me my thesis, that we need to rethink our cultural environment…to connect and embrace nature.On the topic of film, the Quatsi trilogy ‘life out of balance, in part one it projects the material world in which we have wrapped ourselves up in, but more to point, the niche of the film for me, the faces of despair Showing that the erect convulsions of glass and steel are not making us happy, chemical rich foods, causing all kinds of chemical imbalances in our brains, the way we dress, re sculpt and so on because were no longer happy in our own skin …Look around how many people do you see that are happy and free? It is the complexity of us as humans, our senses, the free things in life which bring us joy (as a 25 year single mum with a beautiful 9 year old daughter, with money constraints I went back to basics…food for free I grew all my own food, brought chickens and so on.Every one thought I was crazy, living in urban Birmingham but me and my daughter were healthy and happy) Health is a useful means for rethinking future landscapes… Mountains are natural water filters, pure and free…your post is showing man yet again trying to control the world around him. Destroying the very thing which gives us life. Earth. Our shelter and provider of food and water. thanks…I hope you made sense out of some of this not to good with words but just happy to wake up in the morning. for being here.

  3. So here are some numbers on the impact — numbers for New York City and the US are easy to find, so I used those.

    Drinktap says the average American household uses about 70 gallons per day for “indoor” water use, including dishwashers, laundry, toilets, showers, and so forth. About 11 gallons per day are “faucet”, which is what I imagine the gizmo described here would replace.

    Here is a website which says that New York City gets 914 million cubic metres of rainfall per year, which is around 241 billion gallons.

    And Wikipedia (I know, I know…) says there are about 3 million households in New York City — we need this because the consumption data is per household.

    So, if everyone in New York used this gizmo for “faucet” water, that’s 11 gallons per household times 3 million households times 365 days per year, or roughly 12 billion gallons of the 241 billion gallons, about 5%, that would have rained, but didn’t because it was pulled from the sky.

    If everyone in New York uses the gizmo for all their household water, obviosly it’s about 76 million gallons out of the 241, or a little less than a third of the rain that gets removed.

    Even if I got the arithmetic right, this is obviously this is just back-of-the-envelope (back-of-the-website?), NYC households may not be “average”, rain is not the same thing as humidity, the removed moisture might have smaller, more diffuse impact over a larger area than the city itself — there are lots of potentially complicating factors. But, this seems like it actually is a pretty big impact, which was the opposite of my expectation, I was expecting a “drop in the bucket” effect. I’ll leave it to real climatologists to assess the impact, though.

  4. Imagine if these watermills were concentrated in one area of a large city. Two air masses are about to collide above. But, the watermills create a pocket of drier air, differing from the impending system. The thunderclouds build and rise around the dry bubble creating an amazing spectacle of tall dark clouds and lightning. So instead of stopping these storms, perhaps the watermills could create large more spectacular storms in a small area. A city for thunderstorm lovers.

  5. During cooling season in most climates, airconditioners are already busy performing the same dehumidification work, but on the air inside the conditioned spaces rather than the outside air. Most of this uncounted volume of condensate rains down on pedestrians from thousands of point sources, with the remainder (from central cooling systems) piped into the drains.

    If properly captured, filtered, and stored, this pure by-product of existing infrastructure could be used as easily as that produced by Watermills, without needing the power to manufacture and run the extra equipment.

    I don’t know if any quantitative data exists for this over-looked component of the water cycle, but it seems a pity to let it go waste.

  6. While I love imagining such situations as city-wide drought through air-to-water machines, I however believe that such dramatic effects will not happen, even if every household in a city of 3+ million had such a machine. There’s just too much water in our skies for that to happen. Err, I remember reading a scientific analysis of our atmospheres and in the conclusion it stated how much water we have floating above and around us. Seriously, there’s a lot. And of course we shouldn’t forget that there are no closed systems. Winds continue blowing, things continue moving, our skies are incredibly vast,so while there will be an effect, it will be quite negligible.

  7. There’s an interesting feedback effect between this and solar power: you use solar power to power these, and then you have fewer cloudy days to block the sun…

  8. The point rfr makes, if expanded, points to another interesting series of consequences.

    A humid city (lets say Memphis), recognizing the same point and desperate to reduce its water and electrical bills, bans all new air conditioning installations and subsidizes the installation of dehumidifiers connected to water supplies. By reducing the humidity inside its wooden structures, Memphis finds that they last longer, gradually creating a distinctive architectural footprint of older buildings–a footprint that is made even more distinctive when the New Madrid fault erupts again, bringing down any structure that cannot sway with the shaking.

    Fair disclosure: I’m not an earthquake engineer, and what little I’ve heard about New Madrid suggests that it doesn’t act like most faults.

    In the mean time, the effect on people isn’t just architectural. Progressively deprived of the year-’round chill of AC, residents find themselves forced to accept a more comfortable version of ambient temperatures. This leads to changes in how people dress, with comfort taking precedence over looks. The suit and tie once again become recognized as a sign of seriousness as the only one who would wear one in the heat, however dry, is someone either with the heat tolerance of a cat or a need to endure greater-than-average heat for a specific purpose.

  9. A brief Google search on the subject reveals that condensate harvesting is already underway, particularly for use in irrigation systems. I was surprised to see the quantities available – a mall reports recovering 500 gallons per day and a (large) reserach lab is recovering 60,000 gallons per day.

  10. Of course, cities have already caused local climate modification, with the fields of concrete causing decreased rain drainage, increased evaporation and increased rainstorms. There was a study out of Philadelphia a few years ago …

    Of course, I’m in Atlanta now, and the humidity is bad enough in August it would probably be for the public good, if we could suck some of that humidity out of the air.

  11. While it might not be volumetrically or mathematically possible to dehumidify the whole of New York using WaterMills – creating artificially engineered, linked micro-climates – I do think it’s an interesting proposition. So… I’ll be coming back to this and related topics soon!

  12. i dont really understand why your concern starts with the watermill. i already feel concerned about airconditioning that disturbs the even distribution of temperature during really hot(and many not so hot)days, plus creating some additional heat released to the outside world simply by functioning.this is also done massivelly making hot days even hotter and unbearable.using a car is another massive habit

  13. its interesting to read that the global warming problem and 300years of stupidity in understanding the effect of human activity on nature has not changed us one bit. We do not understand weather systems one bit, yet come up with a watermill (eureka!!!) for “comfort”?? If these hairbrained schemes catch on, we are doomed to extinction and maybe we deserve it…

  14. I’ve been reading BLDGBLOG for a few months now, and want to say how much I appreciate the speculative, science-fictional provocations the author brings to discussions of the built environment. While the Watermill is clearly a silly little con (it costs $1200, is a good three feet in diameter, uses 7.5 kilowatt-hours of electricity to “harvest” a mere 3 gallons of water per day, and won’t work below 30% RH), it provides a terrific taking-off point to consider what we mean by “natural” and “sustainable,” particularly in the context of cities.

    Urban Garlic’s calculations suggest a new standard for evaluating sustainable water use for a metropolis–how does the amount of rain falling on an urban area compare to the amount of water consumed by the city’s inhabitants? If domestic water use already accounts for a 1/3 of NY’s rainfall , I’d guess total water use far outstrips it. Imagine the situation in LA, Las Vegas or Phoenix.

    This in turn implies that the true measure of NY’s size isn’t the square miles contained within the five boroughs, but also must include the area of the watershed that supplies the city’s water. And the area to grow its food. And mine the coal for its power. And landfill its garbage, etc. On the other hand, perhaps the wealth generated in the city, which spreads beyond its borders and allows people to survive in land areas around the world, should somehow be deducted from NY’s effective size.

    Finally, to suggest that a dehumidification scheme effecting a large city is somehow tampering with a natural systems (as some here have) ignores the already-tampered-with nature of the cities. Just one example: urban heat island effect raises city temps well above “normal.” Warmer air holds more water for the same percentage of relative humidity. Thus, the air over Manhattan may actually have more harvestable water now as a built environment than when it was marsh and woods.

    Just a thought.

  15. Of course it’s possible, but that doesn’t make it a good idea. “three to four cents per liter”, with a daily production of 12 liters, is about $0.50 worth of electricity per day, $15/month. At California rates anyway, that’s roughly 4kWh/day, or a constant load of roughly 166 watts: “three light bulbs” is three 60 watt *incandescent* light bulbs, left on 24 hours a day, every day. For comparison, my nothing-special refrigerator from Craigslist uses about $8/month. My chest freezer converted to a kegerator uses $3/month. My computer, external backup disk, 30″ monitor, and desk lamp combined use about as much power as this watermaker… when I’m using the CPU at 100% for numerical simulations day and night. (numbers courtesy of the excellent kill-a-watt power meter)

    Rainwater harvesting and graywater reclamation for non-potable applications will have a much bigger, and much more sustainable, impact on urban water usage. Utterly pure reverse-osmosis desalinized seawater is roughly 10% the price of Watermill water, even by the most expensive estimates, roughly 1% at the bottom end of the estimates, see this study by the State of California

    It’s pure greenwashed marketing fluff, positively comparable to only the grotesquely unsustainable straw man of plastic-bottled water.

  16. FYI…..An Atmospheric Water Generator (AWG), is a device that extracts water from humid ambient air. It is in laymens terms a refrigerated dehumidifier, but with UV lights and filtration all macro contaminants and biologicals are removed from the water to create the cleanest water on the plant.

    Water vapor collected from the air is already filtered by mother nature. She has has already taken out 95% off the contaminants from the water in the evaporation and transpiration process.

    Fun Facts:

    1. Our planet holds at any given time 326 million cubic miles of water. Of this, 97% is saltwater and 3% is fresh water. Of that 3%, 99.3% is locked in ice.

    2. Our air contains 4,000 cubic miles of water. If it were a lake it would be roughly the size of the Great Lakes combined and would be constantly refilled DAILY!.

    With that being said, we could give an airwater machine to every one in the united states and still not scratch the surface of the amount of water in the atmosphere.

    Thats all…………

  17. Ok, so mother nature and man being are one, the evolution continues our disconnecting through technological advance will not destroy the sublime universe we are just a blip… but are these gadgets making us happy?Is there not more important things we could invest our time in?

  18. How could you not mention the moisture farmers of Tatooine? From Star Wars? Remember? That’s what Luke’s aunt and uncle did – farm moisture. From the air. Lucas was so ahead of it.

  19. projecting visions of the future…through film, is the way forward…films are words and pictures…and most are set in the cities of today…artists project a illusion…there are no words without pictures and no pictures without words… this is i feel film offers so many answers of times to come…so anonymous i agree.

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