The Shanghai Academy of Science and Technology has invented a cell-phone sized device that can reduce the amount of power an air-conditioner used by more than 8 percent, it announced yesterday.

The academy, which has applied for patents for the invention on the Chinese mainland and in Hong Kong, said the device can also stop air-conditioners from dripping on pedestrians.

Two air-conditioner manufacturers -- TCL and Jiangsu Province-based Shinco - yesterday signed agreement with the academy to install the device on their products.

"Our invention is simple but useful to save energy," said Li Jianjun, director of the academy's energy and environmental development research center, which created the device.

The device is attached to an air-conditioner by a series of tubes, which collect condensation drops. The water is pumped to the device, which turns it into a fine mist that is sprayed on the back of the air-conditioner, cooling it down significantly. The device is expected to cost about 100 yuan (US$12.50), researchers said.

"The more quickly a machine cools down, the more efficiently it works and the less energy it needs," Li said.

Tests on several air-conditioners show the device can reduce power consumption by at least 8 percent. "The invention is very exciting because it uses the simplest and cheapest approach to saving energy," said Zhao Guotong, an energy expert.

During the hottest part of the summer, air-conditioners account for up to one-third of all power use in the city, researchers said.

(Shanghai Daily August 9, 2006)