NUS ME researchers have pioneered a new “green” air-conditioning system that cools air to as low as 18 degrees Celsius without the use of energy-intensive compressors and environmentally harmful chemical refrigerants. It uses a dehumidifier and the concept of evaporative cooling – such as when a layer of water on your skin vapourises and takes the heat away from the skin, leaving one to experience a cooling effect. Suitable for both indoor and outdoor use, the novel system is portable and it can also be customised for all types of weather conditions. The invention is also 20-30 percent cheaper to manufacture than conventional air-cons, and could save millions in capital and operating costs, as well as valuable space in buildings.
(Straits Times article: http://www.straitstimes.com/singapore/nus-team-develops-water-based-air-conditioner)