China’s solar-heated sand floors keep homes cozy at 65°F even in freezing -1°F
The system featured a solar-thermal collector, a thermal storage tank, an air-source heat pump, a sand-filled thermal storage floor, and water pumps.
Many rural homes around the globe lack modern heating options and rely on wood or coal, leading to health risks and environmental harm. In China alone, around 400 million tons of standard coal are used for winter heating each year, with nearly half burned in inefficient small stoves in rural areas.
Transitioning to cleaner energy sources is crucial to reducing their carbon footprint, especially as global carbon dioxide (CO₂) emissions from fossil fuels and industry reached 37.01 billion metric tons in 2023, according to Statista.
To tackle the issue, Chinese researchers from the Zhongyuan University of Technology and Dalian University of Technology, have come up with a groundbreaking solution by developing a system that connects a solar-air source heat pump (SASHP) to a sand-based thermal storage floor (STSF).
According to the researchers, the system is capable of sustaining an average indoor temperature of 65.8°F (18.8°C), even as outdoor temperatures fluctuate between -1.1°F and 54.1°F (-18.4°C and 12.3°C).
Conducting the experiment
The innovative thermal storage floor system features cost-effective, stable sand-filled coils integrated with a SASHP to enhance rural heating efficiency.
Led by Pengli Yuan, PhD, lead author of the study from the Zhongyuan University of Technology, the team carried out several experiments, after setting up the system in a single-family rural residence in Chifeng, in the autonomous region Inner Mongolia, China.