Air-source heat pumps have been used as essential equipment for building cooling systems owing to their high performance coefficient. The heat pump system operates on the simple principle of absorbing indoor heat and releasing it to the outside. During summer, the high temperature of the outdoor air causes performance degradation and excessive energy consumption in this system. Evaporative cooling technology can effectively improve the heat release performance of heat pump condensers, leading to higher cooling performance and lower energy consumption. In this study, energy simulations were conducted to compare two types of evaporative coolers in order to choose the most suitable one for installation on an actual building HVAC system. A 1076.39 ft2(100 m2) three-story commercial building in Seoul, Republic of Korea, was considered for the simulation. Detailed calculations were performed using the TRNSYS and Engineering Equation Solver simulation tools. Compared to existing systems, the proposed evaporative cooling-based HVAC system saved 16.1% of energy when simulated on a design-day based on the maximum temperature recorded during summer. In particular, the spray type cooler showed the highest energy saving performance; this resulted from conducting the overall energy simulation in summer using pad and spray types of evaporative coolers. Due to the small amount of water sprayed and the low pressure drop, the spray type direct evaporative cooler should be preferentially considered for future building installation applications.