The study proposes a new low-grade energy utilization system, i.e. a pipe-embedded wall integrated with ground source-coupled heat exchanger, and investigates its energy saving potentials in five typical climate regions of China. The cool/hot water produced by the ground source-coupled heat exchanger is supplied to the pipe-embedded wall to intercept the heat gain/loss through the wall. A real-scale building energy simulation platform has been developed for estimating the energy saving potentials. The study results show that the energy saving potential of the proposed system varies with the climate regions. With the same sized pipe-embedded wall system, the building in warm climate regions achieves the largest energy saving percentage. It is followed by the buildings in the hot summer and cold winter climate region, the severe cold climate region, the cold climate region, and the hot summer and warm winter climate region in the declining sequence of energy saving. Meanwhile, a multi-criteria performance evaluation has been conducted to search for the optimal size of the low-grade-energy system in each climate region. The proposed system can be utilized in practice for energy saving, and the study results are helpful in guiding the practical applications of the pipe-embedded wall system in different climate regions. (C) 2016 Elsevier B.V. All rights reserved.