A view of the Jangbei New Area Civic Center in Nanjing

The Jangbei New Area Civic Center in Nanjing, located close to the Yangtze River, boasts a sophisticated central air-conditioning system that uses the river water to control temperatures in the building, the largest of its kind in China.

The facility has no noisy AC condensers installed on the walls or visually-striking cooling towers on the top, but the room temperature remains at around 26°C because of this river water-based system.

River water feels warm in winter and cool in summer, about 10 degrees Celsius different from air temperature, so its application can be more energy-efficient compared with conventional air-conditioners, said Ma Lin, manager of Nanjing Jiangbei Public Utilities New Energy.

Workers inspect the heat pump at the Jangbei New Area Civic Center (Photo/Zhang Yun)

A visit to the center’s energy station, about 12 meters underground, will find pipes of two colors, light blue for river water input and dark blue for return water. As the heart of the AC system, the heat pump unit consists of evaporator, condenser and compressor components.

In summer, the river water flows into the device and the heat pump unit produces cold water to cool the building. In winter, the warmer river water is used by the system to heat the building. The energy station does not change the water’s quality, a good way to protecting the ecological environment.

With a total investment of 3.26 billion yuan, the project will include six energy stations and one water pump station. It also applies energy storage technology at night and then meets the need in peak hours in daytime, which effectively relieves the pressure on the power grid.

Data shows that the center had saved 588,000 kilowatt hours of electricity from its opening in 2020 to late June, compared with conventional air-conditioners. This is equivalent to reducing the use of 455 tonnes of coal and the emissions of 1,376 tonnes of carbon dioxide. As a result, the center has become a role model for the application of renewable energy in Nanjing.

Comparatively, the floor space for the air-conditioning system and maintenance costs for the cooling towers are deceased by 85% and 80% respectively.

Fan Kefei, chairman of Nanjing Jiangbei New Area Public Utilities Holding Group, said centralized cooling and heating solutions based on renewable energy will be promoted in Jiangbei, including the application for residential buildings.