Multi-Source Heat Pump systems are intended to achieve a high system efficiency through the combined or alternate use of two or more sources for a heat pump. This thesis entails the research work to develop a hybrid Ground Source Heat Pump (GSHP) system integrated with a dry cooler with vertical underground loops for single-family houses. TRNSYS is used to verify the feasibility of this integrated system, so as to optimize the control strategy and quantify the energy and energy cost savings. The primary objective is to demonstrate the improved system efficiency of the GSHP through the combined use of a dry cooler in a single-family house under the eight ASHRAE-defined climates. The results indicate that the integrated system would not be an optimal option for houses located in cold climates, but it is feasible to be implemented in hot/warm areas to increase system efficiency at low cost.