Chinese Researchers Develop Affordable and Eco-Friendly Heating and Cooling Solution Utilizing Untreated Wastewater
Researchers from China have announced an innovative and cost-effective solution to keep homes cool in the summer and warm in the winter by harnessing untreated wastewater.
Wastewater from households is channeled through a heat separation device. Thanks to a series of filters, this device retains solid waste, ensuring that the pipes remain unobstructed, while the liquid is directed to a pump that transfers its heat to an absorption unit filled with freon refrigerant. The wastewater then returns to the heat separation device to transport solid waste to a treatment facility. Meanwhile, the freon gas is compressed to increase its temperature and sent to a condenser, where it transfers heat to a water-filled collection unit. A fan then circulates the warm air from the collection unit to spaces that need heating.
“This process uses electricity, but the additional heat from the wastewater makes it up to four times more energy-efficient,” stated Sun Dexing, a professor at the School of Environmental Science at Harbin Institute of Technology. According to him, even in extremely cold regions, the temperature of wastewater in urban areas can reach around 1,000 degrees Celsius, while the temperature in the heat pump is only about 300 degrees Celsius, meaning that wastewater can transfer most of its heat to the freon gas.
In the summer, the process is reversed. Heat from the air is transferred through the collection unit to the condenser and then absorbed by the wastewater. By transferring heat to the wastewater during the treatment process, this device can help mitigate the “urban heat island effect” in major cities in southern China.
Professor Sun remarked: “The heat separation device can replace traditional energy sources like coal for cooling or heating homes. It can be used in places with ample wastewater, such as hotels, apartments, and shopping centers.” This device can reduce heating and air conditioning costs by up to 20%. It is also eco-friendly, as it does not emit pollutants and does not use chemicals. This technology has been successfully tested in a hotel and a shopping center in Harbin, a city in Heilongjiang Province, northeastern China, known for its extremely cold winters.
The heat separation device has been patented and will soon be available on the market.
