Officials in southwest China's Chongqing Municipality have developed an energy-efficient air conditioning system that uses river water to provide heat in the winter and cool air in the summer.

 

The system is said to use between 20 and 30 percent less electricity per hour than a conventional air conditioner during the summer and between 40 and 50 percent less during the winter.

 

The system uses an electric pump that sucks up river water which is then sent to a heater, said Shen Lizhi, an official with the Department of Chongqing Municipal Construction Committee.

 

"In the summer the system will draw the heat out of a room, transfer it to the water and then take it away while in the winter the system will heat the water which will warm the room," Shen told China Daily.

 

He said Chongqing started experimenting with the water-based air conditioning system in late 2005 while searching for ways to save energy. Last year the municipality spent 2 million yuan (US$256,410) using the system on an experimental basis to heat and cool a 600-square-meter area near the Jialing River.

 

"The experiment showed that the system could maintain a room temperature of between 26 and 28 degrees Celsius in the summer and between 16 and 18 in the winter," Shen said.

 

The Ministry of Construction had selected Chongqing to demonstrate the effectiveness of the water-based air-conditioning system because the city has abundant water resources, the construction official said. Both the Yangtze and Jialing rivers pass through the city.

 

Using 1 percent of the water flowing down the Yangtze River, the system could heat and cool 10,553 square meters of residential and public space in Chongqing.

 

Shen said the system would raise the river's temperature by 0.1 degree Celsius in the summer and 0.08 in the winter. He added that the system wouldn’t cause environmental harm to the Yangtze River.

 

The city expects the system to reduce energy consumption and plans to use it to heat and cool 2 million square meters of residential and public space during the 11th Five-Year Plan (2006-10).

 

According to a joint circular issued on Monday by the Chongqing Municipal Construction Committee and the Chongqing Municipal Finance Bureau hotels and supermarkets with floor areas of 20,000 square meters and residential buildings with floor areas of at least 100,000 square meters can apply to be connected to the new system.

 

(China Daily January 23, 2007)