Air conditioning, as anyone who lives in more tropical climes, is not so much a luxury as it is a necessity. Without the ability to keep homes and other enclosed spaces during the summer months cool, people are not only uncomfortable and sweaty but are often in grave danger of dying of heat stroke.

Unfortunately, central air conditioners are not only energy intensive but also come with certain environmental costs and risks. Modern Air Conditioner systems work by transferring heat from an enclosed space and passing it outside, using expensive and toxic refrigerants to do so. Environmentalists, especially those who live in northern parts of the world, hate air conditioners and would like to see their use curtailed.

Fortunately, a group of researchers has developed what may be a cheaper, more environmentally friendly air conditioner that can be scaled from a hand-carried unit to one that can cool a building. As a bonus, the technology provides Drinkable Water.

The water-cooled air conditioner

The team at the National University of Singapore have developed an air conditioner unit that eschews the expensive refrigerants and costs much less to run. The process starts by passing air through a paper-like membrane that removes the moisture. Then the air is passed through a dew-point cooking system that uses the extracted water to cool a series of metal plates, thus cooling the air as it passes through. This step works on the same principle as human sweat does to cool the body. The air that comes out the other end is cooler and drier.

The water-cooled air conditioner takes 40 percent less energy to operate than the conventional kind. The experimental unit creates 12 to 15 liters of drinkable water a day.

Taking the technology to the real world

The team from NUS is currently refining their technology and are looking for commercial partners to market it to customers. The water-cooled air conditioner can be scaled up to cool private homes or even clusters of apartments or commercial buildings. Smaller units can take care of enclosed spaces that need to be kept at a constant temperature such as hospital operating rooms, wine cellars, tents in refugee camps, and so on. Indeed, since each unit also produces drinking water, the technology will have the side benefit of addressing another problem in the developing world, lack of potable water.

Retrofitting homes and buildings, which have been designed around conventional air conditioners that have inside evaporators and outdoor compressors, will be quite a challenge. However, since the most significant energy expense for most people is running the air conditioner, the expense might well be worth the effort.