Advanced control strategies in heat pumps must be developed to achieve a high energy efficiency in real time while ensuring thermal comfort. The objective of this study was to investigate the dynamic performance characteristics of a heat pump with consideration of the energy efficiency and thermal comfort. A dynamic simulation model for a heat pump was developed and validated using experimental data. The dynamic characteristics of the heat pump were analyzed at various outdoor fan speeds and compressor frequencies. The optimum outdoor fan speed and compressor frequency were determined to be 800 rpm and 50 Hz, respectively, for achieving the maximum energy efficiency. When the heat pump was operated to satisfy thermal comfort under the optimized conditions, the cooling time and energy consumption decreased by 56.5% and 74.8%, respectively, compared with the baseline cycle.