TY - JOUR TI - Vertical U-shaped heat exchangers for construction engineering: New promises and future challenges AU - Liu Yin AU - Xu Sensen AU - Yuan Dongyan AU - Meng Zhaofeng AU - Gao Long JN - Thermal Science PY - 2021 VL - 25 IS - 3 SP - 2253 EP - 2261 PT - Article AB - The ground source heat pump system is a promising technology for building heating and cooling by using underground energy, however, many technical problems, e. g. low energy utilization rate and inefficiency operation, have greatly hindered its wide applications. This paper studies the key technologies of vertical U-shaped heat exchangers in construction engineering to solve the bottleneck problem and optimizes the system. Three commonly used backfill methods are analyzed, and a double U-shaped branch pipe is recommended to improve construction efficiency. The paper sheds a bright light on green energy utilization with high-efficiency, energy-saving, and environmental protection.