Generating Water Out Of Thin Air (Atmospheric Water Generation)

How To Generate Water Out Of Thin Air (Atmospheric Water Generation)

In addition to having a desiccant dehumidifier in our gun safe, we also have another, much larger, plug-in dehumidifier in the room where the gun safe is to take some of the load off of the one in the gun safe.

A few months back, I had an “Ah-Ha!” moment as I was pouring out the water in the dehumidifier and realized that this was another source of water in a disaster situation. 

As incredibly obvious as it is, I had never had to use a dehumidifier until this summer and I thought I was a genius.  I immediately started trying to figure out whether it was a viable large scale product.

What struck me as interesting is that even though we were miles from groundwater and that the humidity was very low outside, the desiccant in our safe was still sucking a lot of water out of the air and our dehumidifier was pulling a quart of water or more per hour out of the air.

I knew that our current location would make things challenging in a survival situation because of the groundwater situation and the lack of rain.  In the last 6 months, we’ve received just over an inch of water, and it has come in a few sprinkles that weren’t even enough to get water to our downspout. 

Seeing ready-to-use water generators made me very excited to have another possible strategy to simply storing water and catching the incredibly infrequent rain.

The first hurdle I ran into was the fact that our dehumidifier is an energy hog…using 1700 watts per hour.  60 watt light bulbs are pretty common and this is the equivalent of running 28 of them simultaneously.  This would take the entire output from my 2000 watt generator or a fairly expensive array of solar panels to power. 

In a survival situation, without a $10,000 solar system to power my dehumidifier, I’d simply be swapping fuel for water, which meant that my water supply was limited by the amount of fuel I could store.  This was, obviously, a hurdle that I had to get over.

The second hurdle that I ran into was that the water in a dehumidifier tank isn’t really safe to drink.  I’d drink it, and a lot of other questionable water in a pinch, but I wouldn’t want to make a habit of it. 

In addition to having traces of whatever metals/solder the dehumidifier fins are made of, it also concentrates whatever pollutants, fungus, bacteria, and viruses happen to be floating around in the air of your house

This is a common hurdle for dehumidifier water, rain catchment, air conditioner water, and most urban water supplies, so it’s not that big of a deal…it’s just something to be aware of.

Since I had the water purification part of the equation taken care of, I decided to start looking for high efficiency dehumidifiers.  In the process, I found that there were already dehumidifiers coupled with water purifiers called “Atmospheric Water Generators” or AWGs.

As it turns out, the idea of sucking water out of the air and making it drinkable is quite old, dating back to passive systems that were used in the Middle East almost 2,000 years ago that used piles of cold rocks to cause moisture to condense out of warm air.

Fast forward to modern times and we see that the technology to turn air into potable water using portable units was first patented in 1992, and put into mass production in 2004.  Today, there are units that range in size from household units that generate a few gallons per day to semi-truck sized units that generate thousands of gallons per day in use around the globe.

This is yet another area that has benefited from a growth in the number of people who are looking for ways to become more self-reliant by going partially or completely off-grid.  Today, there are dozens of options using a handful of technologies to help you extract water from air.

The two main technologies are dehumidifiers coupled with water purifiers and using reusable desiccants.

In the desiccant atmospheric water generators, desiccants are allowed to absorb water during the most humid parts of the day and then heated to cause them to release their water.  If you’re not familiar with desiccants by name, you will oftentimes find them in vitamin bottles or in bags/cans for dehumidifying safes and gun cases.

As I started doing research, I found that almost all of the units were energy hogs, requiring 400-900 watts to run—not quite as bad as my 1700 watt dehumidifier, but not efficient enough to be practical in a survival situation.  Even if I was in an area with high humidity, like most hurricane prone areas are, the sheer amount of power required made the units impractical.

In addition, they used up to a dozen steps for filtration/purification and used a lot of electronics.  To me, it seemed like there were more points of failure than necessary.  After all, while the engineer in me loves the complexities of Rube Goldberg machines, I want something that’s going to be resilient in a survival situation.

Even though I knew it wouldn’t be the ideal solution, I decided to go  ahead and buy a generator. Frankly, I wanted to see if it would be an all-in-one solution that I could recommend to my readers, and I didn’t want to recommend it without using it first.  I ended up getting an EcoloBlue 30, which will generate 30 liters per day at 80 degrees and 80% humidity while drawing 280 watts.

One thing to note on the EcoloBlue AWGs, is that the “guts” of the unit are used in a hand-full of brands of AWGs, like “Atmos” and “Advanced Ultra Water Manufacturing”  Different companies simply throw a different shell over the guts and market it under their own name.  I may end up doing something similar in the near future.

The fact that the same guts are marketed with different names is important, not only because it means that replacement parts are somewhat easier to find, but also because EcoloBlue is fulfilling single orders of 100 or more units and it can take up to 6 weeks to get your unit if they have a backlog at the time.  Having an alternative brand that you can buy could get one in your hands much sooner.

After almost 8 months of using our EcoloBlue on a regular basis, I’ve got some solid first hand knowledge to share with you.

To begin with, I’ll answer the most obvious question—Yes, it does work!  There have been weeks where most of the drinking water that the 4 of us drank was from the unit.

We haven’t had any days where we’ve been able to get the full 30 liters from it, but that’s because we don’t run it 24/7 and because the humidity in our house ranges from 35% to 60%, with the norm being 40-50%.

Here’s a chart of how much water you can expect to generate per day, as well as the cost per gallon assuming an ambient temperature of 70 degrees.  Production increases with higher ambient temperatures, so these numbers will be conservative for most people.

As you can see, it’s not a perfect solution by a long shot.  The power consumption is fairly high, and water costs well over 20c per gallon in electrical costs alone at lower humidity levels. 

When you add in replacing filters every 6-12 months and a 10 year life expectancy for the unit itself, (this is a guess, as none of the manufacturers list a life expectancy for the units) the cost goes up even more.

But, and this is a big point, almost every preparedness/self-reliant alternative to “store bought” food, water, fire, fuel, and electricity costs more in terms of either time or money.  Yes, it’s cheaper to get water from the tap…just like it’s cheaper to get gas from the pump and electricity from the utility company, but I believe that it’s worth it to either use more self-reliant solutions on a regular basis or have proven solutions available to use in the event that easy “store bought” solutions aren’t an option.

When we use public utility prices as a benchmark for what things “should” cost, we have to take into account the fact that they value efficiency and low prices today vs. being able to provide service during non-ideal situations. 

Having self-reliant or off-grid solutions like this let you enjoy the best of both worlds…the unsustainable low utility prices that we get to enjoy on a day-to-day basis AND a backup small scale solution for disaster situations when large scale solutions don’t work.

This mindset really applies to everything that operates on a just-in-time system…from utilities to food, &  from fuel to medications.

So, how do these units work?

They start off by taking air and running it through a rudimentary air filter.  The purpose isn’t to “purify” the air, but rather to minimize dust and hair inside the unit.

Next, the air goes over a set of condenser coils that are coated with a food grade coating to minimize interaction between water and the metals/solder used for the cooling coils.  The condenser is cooler than room temperature, causing the air to release it’s “extra” humidity…like what happens when you open your freezer door.

The water then goes through a carbon charcoal filter to eliminate chlorine and other VOCs.  All of the sales literature says that this step also removes ammonia, but carbon charcoal filters don’t remove ammonia.

The filtered water is collected in a small, roughly 2 liter tank.  When it fills up, the water gets treated with UV light, which kills 

bacteria, viruses, protozoa, mold spores, and inhibits bacteria growth in the reservoir.

After getting treated with UV light, the water is pumped through a series of 2 carbon charcoal filters, a reverse osmosis membrane, a mineral filter, and a final carbon charcoal filter.

After going through this set of filters, the water goes to a holding tank that is periodically exposed to UV light to minimize or eliminate bacteria growth in the unit.

When you decide to use water in the tank, it goes through a cold water pump, or through a hot water tank.  The water that goes through the cold water pump is again treated with UV light at the outlet.

The end result is very good tasting water that’s satisfying, in part, because of how it makes me feel like I’m “beating” the system and have found another emergency source of water for my family.

Another way that you can use these units is to run a hose to the back of the unit like you would to a refrigerator ice maker/water dispenser.  Then, you can take advantage of the filtration system as well as the heater/cooler during non-water emergencies and switch over to generating water if your utilities go out.

Pricing on these units are all over the place.  They’re based on supply and demand, and to a certain extent, where disasters are happening in the world on the particular week that you’re looking.  Plan on spending $1,500-$2,000 and be happy if you find one for less.  You can find units for significantly less, but they’ll be models that use significantly more power.

One drawback of the units is that they’re somewhat loud and they are designed to only be used indoors.  They’re not obnoxiously loud…somewhere between a refrigerator and a dishwasher.  The ambient noise level in our living room is 40 db during the day with normal stuff turned on. 

When we turn on the AWG, it gets as high as 65 db, depending on which cycle it is on.  We turn it off when we’re eating or having a quiet conversation in the same room, but I wouldn’t say that we need to.

The units are expected to last 5-10 years, depending on whether or not the filters are properly cleaned.  This bit of information was very hard to find, seems to be an estimate, and didn’t seem to be proven out by actual results yet.

Ecoloblue was very good to work with.  They answered questions quickly and they understand preppers.  One thing to note is that some of their units say that they have a “Solar Option.”  This simply means that you can hook up solar panels to batteries and an inverter and run the AWG.  It doesn’t mean that they run on 12V or that they have any special features that make them work well with a solar system.

Would I recommend the units?  That’s complicated.  If you’ve got room, you can buy several 55 gallon water barrels for $20 apiece or a 1,000 gallon water tank for $500.  If you’ve got a source of groundwater or get frequent rain, then it might not be necessary. 

But, if you want a compact plug-n-play water generation solution that you can use as a water purifier now and as a water generator in the event of a disaster, then it may be a good fit.