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Health & Wellness

2008-08-01 09:35:00

Atmospheric water generators

Question: I recently heard about a home appliance that produces pure drinking water, but it is not hooked to any water line. They said it harvests the water from the air. What is this all about? How does it work?

Answer: What you have heard about is called an atmospheric water generator, or as it is sometimes called, an AWG. This is a new refinement of something you have seen many times in the past, but it opens up a whole new option for people who do not have satisfactory tap water available. What you have seen many times, I am sure, is water dripping off an air conditioner coil. Maybe you saw it coming from a window air conditioner, or maybe you saw the water puddle forming under the engine area of your car after you drove it on a hot day with the air conditioner running. The water is condensate. When warm humid air passes over the cold air conditioner coil, the air is cooled, and some of the water vapor in the air condenses into liquid. How much liquid water is created is a function of the relative humidity, the difference in temperature between the air and the coil, and the quantity of air passing over the coil. That is the physics of what is happening, but for many people, they could care less about the science. They are much more impressed by the results. An AWG is an appliance that plugs into an electrical outlet, and it uses the science I have just described. However, the AWG is designed to maximize the amount of water it harvests from the air while using as little electricity as possible. And, since the AWG is designed to provide drinking water, there are many enhancements that are required for maintaining purity and good taste. To start with, an AWG filters the air as it enters the unit to remove airborne impurities. The cold coil that causes the condensation to form is made of food grade materials, as are all of the materials that come into contact with the water. Many pieces are stainless steel. Also, the water itself must be purified, which is done by treating it with either UV light or by adding ozone. Some AWG units use both. As a result of these technologies, a good quality AWG will produce some of the most pure water available anywhere. Compared to the water produced by filtering tap water through a typical reverse osmosis system, such as that sold in many popular brands of bottled water, an AWG might produce water with only 1/10 of the impurities, or less. A typical AWG contains a 2 or 3 gallon water storage tank, and the unit only runs when water is removed. When the tank is full, the unit shuts off again. Also, in order to maintain the purity of the water stored in the tank, it is periodically pumped back through the UV and/or ozone water purification system. This allows you to be gone from home for a few days, and when you return, the water will taste as pure and fresh as when it was first made. Another nice feature of many AWG’s is that they refrigerate the water, so when you fill your glass, it is with pure cold water. Some have a second water tap that allows you to get hot water also. Most AWG’s that are designed for use in a home or office will produce at least 3 to 5 gallons of water per day, and under the right conditions, can produce up to 10 gallons. Atmospheric Water Generators are becoming common in some parts of the world, but they are relatively rare in North America. However, with the water problems many people are experiencing, I would have to think we will be hearing about them much more in the future. The market for these units will develop gradually, just as happens with most new technologies when they are introduced. Some of the target markets for AWG companies will be people without an adequate or reliable supply of domestic water, people with bad tasting or polluted water, and as an alternate to bottled water. In case you are wondering about cost, I find that most AWG manufacturers sell their units with a retail price in the $2000 to $2500 range. As with any appliance, the more bells and whistles, the higher the price. While this price might seem like a “boatload,” it’s nominal if you don’t have good water. What’s more, there’s not much expense after the initial purchase as there aren’t a lot of parts to wear out. I have found that most manufacturers claim an average cost to operate their AWG at about 10 cents per gallon of water produced. If that is true, an AWG could pay for itself reasonably quickly based on the savings of bottled and distilled water alone. It will be interesting to watch this new product become available in our country and see how people respond to it. And if you’re wondering why I know so much about an AWG, it’s because I can’t seem to turn down a new idea. I have recently ordered one for my personal use, and I expect it to arrive in a few days. I will be telling you about what I find in coming issues.