Monday, December 15, 2008

Water Mill as Eden Machine

This story is about an atmospheric water harvesting device operating on household current and producing a supply of drinking water. This is a nice design compared to other examples that I have also seen. Because the intent is to supply potable water, there is a lot of design effort in the problem of polishing the water.

The Eden machine described last week will be stripped of such extras and will focus purely on separating the water from the atmosphere. The importance of controls and sensors is clearly indicated.

Obviously the water can be distilled from the atmosphere but is also likely to collect its fair share of dust. Since it is meant to go directly into the ground, this is not an issue. If it should be used for drinking water, there are plenty of options for operators to use on their own.

The one advantage this particular design protocol has is that you can count of household humidity of over 60% even when outside humidity is a mere 15%. Yes we do expel that much water.

It is much more problematic in the open field with variable humidity and has to be managed by the control system.

What this simply demonstrates is the reality of the protocol itself. It should never be in dispute and that is one unneeded prototype field test.

Our objective will be to produce several times as much as demonstrated here for a comparable selling price. That is the technical challenge that is now achievable.

Turning air into water? Gadget does just that

WaterMill is touted as a pricey but environmentally friendly H20 source

A new home appliance called the WaterMill converts outdoor air into nearly 13 quarts of fresh water every day. Touted as an eco-friendly alternative to bottled water, the appliance uses ultraviolet light to cleanse itself and advanced sensors to efficiently adapt to its surroundings.

By Bryn Nelson


updated 6:02 a.m. PT, Mon., Dec. 8, 2008

Remember those sweltering summer days when the air was so muggy you could practically drink it? A
new home appliance is promising to make that possible by converting outdoor air into nearly 13 quarts of fresh water every day.

Originally envisioned as an antidote to the shortage of clean drinking water in the world, the WaterMill has the look of a futuristic air conditioner and the ability to condense, filter and sterilize water for about 3 cents per quart.

At $1,299, the 45-pound device doesn’t come cheap, and it is neither the first nor the biggest machine to enter the fast-growing field of atmospheric water generators. But by targeting individual households with a self-cleaning,
environmentally friendly alternative to bottled water, Kelowna, British Columbia-based Element Four is hoping its WaterMill will become the new must-have appliance of 2009.

“The idea is making this thing intelligent,” said Jonathan Ritchey, inventor of the original WaterMill prototype and president of Element Four. “So what happens is the machine knows where it is. If you put it in a rainforest, it will sample that environment every three minutes, and it will adapt.” Ditto for a desert. That adaptation, he said during a November preview at Manhattan’s WIRED Store, is critical for energy efficiency.

Cooling the machine’s condensation chamber to just below the dew point, or the temperature at which the air becomes saturated with water vapor and begins to condense, is central to the process.

“If I have a dumb machine, it might bring the air down to just three degrees above dew point and I wouldn’t get any water,” Ritchey said.

“If I take the air way below the dew point, I’m using what’s called latent heat. It’s sort of like taking an ice cube and trying to freeze it some more. You’re just wasting your energy.”

The unit’s activated carbon filter offers another feature not found on most appliances.

“We’ve actually designed a system that knows when the filter is spent and will tell you, the consumer, ‘Time to change the filter, time to change the filter,’ Ritchey said. “And then if you don’t, we’ve got it dummy-proofed. It will shut itself down. Either you change the filter, and it makes pure water, or it doesn’t make water at all.”

Microbes are another big concern in water coolers, hot water tanks, industrial-sized air conditioning units and other places where water vapor can become contaminated.

The WaterMill was designed to overcome that issue with a self-sterilizing condensation chamber that boasts a reflective wall surrounding its condensation coil. During the machine’s daily sterilization cycle, UV light ricochets off the wall and efficiently sterilizes both the front and back sides of the coil.

Most environments around the world have plenty of water vapor that can be converted into liquid water. In fact, if you could wring out all the water in the air around the world and pour it into a lake, its volume would equal about 3,095 cubic miles, or more than that of Lake Superior, according to the
U.S. Geological Survey.

Element Four estimates that its machine can convert between 10 percent and 40 percent of vapor into liquid water, depending on the relative humidity.

In 91 degree heat with 69 percent relative humidity, the machine tops out at a little less than 13 quarts per day. And because water vapor is continually replenished though the planet’s water cycle, removing it from the air could continue indefinitely without disrupting local ecosystems.

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