Early in the 1950s, Tianjin University's Research and Training Center for Thermoenergy began research on heat pumps. In 1965, the center developed China's first water-cooled heat-pump air conditioner. Yet China's heat-pump industry did not get off the ground until the last few years. The industry is growing vigorously, blessed by China's relatively strong research and application of heat-pump technology, and both the domestic and international drive in promoting energy conservation and renewable energy development.

Tapping unlimited heat

There are hot springs around Beijing's Fangzhuang neighborhood. It is said that emperors in the Tang (618-907?and Ming (1368-1644) dynasties once bathed in a hot spring there. After the baths, the emperors were invigorated and made great achievements.

But the water drawn into the heat pumps in Fangzhuang is regular underground water, rather than water from hot springs.

"The source water has a temperature of 13 degrees Centigrade when it is pumped into the evaporator. After heat is absorbed, the water is cooled down to 6 degrees Centigrade. The cooled water is then returned to the ground," said Hu Weiwei, Project Manager of the heat-pump air-conditioning project in Fangzhuang's Fangziyuan community. Heat is stored in the compressor to warm a refrigerant to 45 degrees Centigrade, which is then sent into the households.

Heat pumps were also installed in the Olympic Village, which brought cool breezes to the residences of athletes competing in the Beijing Olympic Games last Fall. The energy source for those heat pumps was not underground water, but sewage water in the neighborhood. "Using urban sewage water or industrial waste water is more economical and environment friendly than using underground or surface water," said Fan.

Even in places without adequate water supply, heat pumps can still function. Geothermal heat pumps can absorb energy through pipes buried in the ground. "At a certain depth underground, there is a thermostat layer, where the temperature does not vary much between south and north China," Fan said. Geothermal heat pumps can be used more widely than water-source heat pumps.

Even in heavily congested urban areas where there is little space to bury pipes, heat pumps can work, for they can draw energy from the surrounding air. The heat supply from the air is unlimited and low-cost. By replacing water-source pumps with air-source pumps, a large amount of water can be saved. "The key criterion for measuring the technical sophistication of air-source heat pumps is the temperature of the source air," Fan said. Lower temperature air is more challenging for a heat pump to work. Fan said researchers spent 10 years creating a heat pump that can function in cooler temperatures-from zero degree Centigrade in the Yangtze River basin to minus 15 degrees Centigrade in north China. Now, a heat pump from Fan's company can draw heat from air that is minus 20 degrees Centigrade and heat a room to a temperature above 20 degrees Centigrade.

China's heat-pump technology is internationally advanced. Yet heat pumps have not spread to a large part of China. Lu Zhicheng, President of Tsinghua Tongfang Artificial Environment Co. Ltd., said it took a long time and a lot of money to develop the heat-pump technology and then to commercialize the products.

Tsinghua Tongfang Artificial Environ-ment Co. Ltd. is much better known in China for its IT technology than its environment technology. Developing environment technology took more time and patience, Lu said. The company suffered business setback for several years and shareholders were skeptical of the performance of the management team. Lu himself once hesitated over whether he should step down. But he held on because he believed the future would be bright, he said.

Now 30 percent of the company's income is from its energy and environment business, Lu said, and the profit from green products and technology has exceeded that from its IT products. "The company's green business reflects our brand value. We have a consensus to promote social responsibility through scientific and technological innovations," Lu said.