Photo via jenny downing via Flickr CC
As the water crisis becomes more real, with droughts, pollution, depleted snow packs and other issues shortening our fresh water supplies, there is one technology that you'll want to boost your water IQ with - atmospheric water generation. While it sounds like something for a distant, drastically different future, there are actually residential water generators on the market today. Find out how the technology works, and what options are out on the market if you want one for your home.
Atmospheric Water Generators, aka Home Water Makers, Explained
What's an atmospheric water generator?
There are multiple ways of generating a fresh water supply, from fog fences to desalination plants. However, there are also water generation technologies for residential homes, as long as the atmospheric conditions are right. If there is the right mix of humidity, temperature and altitude, an atmospheric water generator (AWG) takes advantage of the natural process of condensation through dehumidification.
How does a water maker work?
Essentially, the AWG is plugged in, a coil is cooled so that warmer air passing over it condenses from vapor to liquid. The liquid is captured and stored in a holding tank as fresh drinking water. As long as humidity is above 40%, the altitude is below 4,000 feet, and the ambient air temperature is above 35°F, water can be collected.
Chart from Air2Water showing how the Dolphin 2 works, which is much how most AWGs work.
But the amount of water a machine can collect and how energy efficient and cost effective its use is, all depends upon a balance of ideal conditions. In other words, you might run your machine more to collect a little water on Monday, and run it less to collect a lot of water on Thursday.
Chart showing the range of humidity and temperature in which the Water Master C2000 can generate water; illustrates the variations in atmospheric conditions that affect a water maker's ability to efficiently collect water.
There are also typically a series of filtration systems to purify the air that is pushed through the device so that the coil on which the water condenses is kept clean, as well as water filtration systems for the water that is collected. In fact, in order to meet FDA and NSF standards for water purity, many systems take advantage of one or more filtration techniques, including among many methods, UV light chambers, carbon filtration, and water recycling so that water in the holding chamber is re-filtered after sitting for a certain amount of time.
Several models also come with perks, such as options for hooking into your tap so that once whatever water in the holding tank is used up, the owner can still use the filtration system for their tap water, or separate tanks so that hot and cold water are available on demand.
Don't water makers use a lot of energy?
AWG use a lot of energy to generate water, which is why even though commercial sized generators exist, they aren't being explored as diligently as desalination plants for large scale fresh water generation. However, new technology is being explored to utilize renewable energy sources for powering systems.
Photo via Bohman via Flickr CC
Still, for home residential water use, AWG wattage ranks anywhere from 300 watts to 1200 watts depending on the size of the device and its generation capacity. In other words, they rank on the scale of a PC desktop computer system, or a home entertainment system complete with plasma TV and XBox. When doing a cost analysis to find out if the energy use is worth it, usually it proves to be less expensive than buying bottled water, but siginificantly more expensive than tap water with a filtration system.
However, many systems also utilize automatic features that minimize power use. For example, most come with sensors that detect when the holding tank is full and shut off. Another model listed below checks the dew point every few minutes and adjusts its coil temperature so that water generation is maximized throughout the day and wasted energy is minimized.
Does a water maker generate enough water for a household's needs?
For drinking and cooking, a water generator under ideal conditions can often generate as much water as a small family needs.
However, for entire household use, it definitely doesn't mean independence from municipal water. Various models generate various amounts depending on atmospheric conditions, ranging anywhere from 1 to 7 gallons a day. This means that current models with current technologies offer an option for a back-up water supply, or clean drinking water away from the tap; but they can't generate enough for an average American household, which uses an estimated 180 gallons of water a day on everything from showers to landscaping.